House Mechanical Systems

Without mechanical systems to breathe life into it, a house is only a brick, mortar and wood shell. It can be constructed with the most modern building techniques and using the most modern building equipment, but without properly working systems, the house really can't perform its functions of providing shelter and comfort. All of these systems — from heating to plumbing to electricity — must be installed properly and constantly kept in efficient working order.



Some time, thousands of years ago, long before the wheel was invented, a caveman brought fire inside his cave and thus invented the first home heating system. Most likely, the cave filled with smoke, causing the cave man’s eyes to burn and his lungs to choke. If he was lucky, the cave had a hole in the top and the smoke escaped through this primitive chimney.

In the majority of Greek and Roman houses, the hearth was the focus of cooking and heating. The Romans had a system, called a hypocaust, which was used only by the very rich. Heat from a furnace was collected under the floors and distributed to rooms throughout the house.

In the East, the kangi was used for centuries (and still is today

in India and Turkey ) to provide heat. It is simply an earthenware container filled with hot embers. Often it's placed under the dining table and covered with a heavy cloth.

The principal method of home heating has been, for more than a thousand years, a fireplace in the kitchen and more recently, in other rooms of the house as well (see “Fireplaces” in Section 5). Hot water throughout this same period was made in a pot, kettle or another container heated in the fireplace or on the cooking fire. Benjamin Franklin’s stove was a major advance. Its warm cast-iron sides radiated heat throughout the room.

The first modern central heating systems were built during the 1800s. They consisted of a boiler producing steam that was circulated by pipes into large, ornate cast-iron radiators. The boilers were fired by furnaces hand-fed with coal or wood as fuel; ashes and clinkers also were hand- removed at regular intervals.

The central-heating and hot-water systems of today generally are less than 100 years old. In many areas of the world, including England, modern systems were rare until after World War II. It is possible with today’s systems to maintain a level temperature throughout a house all year around, regardless of the exterior temperatures.

Central-heating and hot-water systems can be classified by dividing them into the kinds of fuels or the type of transfer medium used to carry the heat from the ignited fuel to the rooms in the house.

This section begins with a short explanation of the principles of heat. Then heating systems are explained, according to the transfer medium. Heat controls and hot-water systems are discussed, as are fuels and the methods of calculating their relative costs.

Principles of Heating

To understand the various heating systems and how they work, it's necessary to know a little about heat itself and what makes people feel warm or cold, for the principal purpose of a heating system is to make the people living in a house feel comfortable.

The body itself has its own heating system, providing enough heat for human survival in a wide range of temperatures, which explains how the human race survived so long ago without much heat. Maximum com fort, however, is obtained in a vary narrow range of temperatures and only when the heat loss given off by the body by radiation, convection and evaporation is in balance. When heat loss is too slow, a person feels hot, and when heat loss is too fast, he or she feels cool.

Radiation is the transfer of heat by direct rays form the body to cooler surrounding objects, such as cold windows, walls and floors. A person placing a hand next to a cold wall will feel a chill as the rays leave the hand.

Convection is the transfer of heat by circulation of air around the body. The movement of the air by wind or a fan or a draft speeds up the heat loss and chills the body. Evaporation is a minor source of heat loss.

The ideal heating system should supply the amount of heat that will keep the body-heat loss in balance. It also must prevent drafts, warm the floors and walls and provide steady temperatures from room to room and floor to ceiling.

Hot-Air Gravity Systems

The gravity-air system enjoyed wide popularity despite its deficiencies and still is being installed in some small houses. Cold air is heated in a furnace that looks like a giant octopus. Because hot air rises, it goes up unaided in a series of ducts and into the rooms being heated through wall, floor or ceiling registers (see Figure 8.1). When the air cools, it descends through other ducts or hallways by the force of gravity. This system is characterized by the uneven distribution of hot, dirty, dry air throughout the house. With some rare exceptions, in houses under 1,000 square feet, this furnace should be replaced with a modern forced-air system.

Fig 8.1 Gravity Hot-Air System

Another type of gravity-air system is a floor furnace. These also are used in small houses, especially in moderate climates. The furnace is suspended below the floor and the hot air rises from the furnace through a flush grille in the floor. There usually are no ducts. The system is inexpensive to install. The larger the area to be heated, however, the poorer the heat distribution.

Space heaters are rarely satisfactory except in mild climates or in cottages or for supplementary heat in areas beyond the main heating system.

Forced—Warm Air Systems

The forced-air system corrected the deficiencies of the gravity system. With this system, the furnace has a fan or a blower that pushes the warmed air through smaller ducts. These ducts may be run horizontally as well as vertically, allowing considerable flexibility in their placement. Filters can be installed in the system to clean the air and a humidifying system can be included to add the needed moisture. The air does not have to be as hot as in a gravity system.

A properly maintained and adjusted system does not create dirt or dust. It does, however, stir up already existing dust and redistribute it. This may be turned to an advantage by installing throwaway filters that will remove the larger dust particles or an electronic air cleaner that electrically charges the dust particles and removes as much as 90 % of them by attracting the particles to metal collecting plates. An additional advantage of this system is that often the ducts can be used for air- conditioning.

A common way to lay out the ducts is called the trunk line or extended plenum system (see Figure 8.2). A large trunk line (plenum) extends from the furnace across the length of the house under the first-floor joists. From the plenum, ducts run to the various rooms of the house. A return-air intake gathers the cooled air through return ducts. The air passes through a filter into the bottom of the furnace, where it's reheated and the cycle begins again. The fan creates a pressure in the plenum that forces the air through the ducts and out the registers and also creates a negative pressure that draws the air back into the return ducts. In better systems, the warm-air ducts are under the windows and along the cold outside walls of the house. Money can be saved at the cost of comfort by short duct runs to the inside walls.

Fig 8.2 Extended Plenum System

An extended plenum system is good because it responds quickly to temperature changes and it's economical to install in houses with basements or crawl spaces. It can be adapted by insulating the plenum and altering the registers to force the air upward to use for air-conditioning. It also adapts itself to the installation of air-purification and humidification equipment.

Perimeter systems can be used in houses built on concrete slabs or in houses with basements and crawl spaces. They require a downflow furnace that blows the warm air downward and accepts the returning cool air in through the top.

In a perimeter radial system (see Figure 8.3), ducts extend directly from the furnace to the various heated rooms by going under the floor joists or through the walls. The air is discharged through registers, which should be placed along the cold outside walls for best results. Cool air re turns to the furnace through return ducts or under doors. A room will not heat properly without a way for the cool air to return to the furnace.

Fig 8.3 Perimeter Radial Duct Warm-Air System

A more sophisticated system is a perimeter loop system (see Figure 8.4). The warm air is fed from the base of the furnace through feeder ducts into a duct that runs around the exterior wall of the house with registers under the windows in each room. This results in a warming of the concrete slab that eliminates the cold-floor feeling. As with the radial system, provision must be made for cool-air return from each room.

Fig 8.4 Perimeter Loop Warm-Air System

Warm-air perimeter systems are economical to install. They require little floor area, which is important in houses built on concrete slabs. and they can be adapted for summer cooling systems. Figure 8.5 shows the types of air registers.

Fig 8.5 Air Registers

Hot-Water Heating Systems

In a hot-water (hydronic) system, water is heated in a boiler of cast iron or steel. It then is pumped by one or more circulators through finger-size tubes into baseboard panels, radiators or tubes embedded in the walls, ceilings or concrete slab. Water is an excellent heating medium, retaining heat longer than any other common medium.

Some older systems, like the hot-air gravity system, depend on gravity for circulation. The more modern units have one or more circulating pumps that are controlled by thermostats pumping hot water into the pipes when heat is called for.

In a one-pipe series connected system, the radiators, baseboard panels or convectors are connected so that the pipe runs through each unit (see Figure 8.6). The main advantage of this system is its low cost. The major disadvantage is that because the water must run through each unit, there are no individual control valves. Also, the units at the end of the loop aren't as hot as the first units on the loops. By dividing the house into more than one loop or zone, each served by a separate circulator connected to a thermostat, some separate control is achieved. An alternate method of control is to have separate loops off a common circulator with a motorized valve connected to a thermostat regulating the flow of water through each loop.

Fig 8.6 One-Pipe Series Connected Hot-Water System: This system may be identified by looking up at the part of the basement ceiling that's directly under the first-floor radiators. In a one-pipe series connected hot-water system, one wide-diameter pipe will be seen going in and out of each radiator. There will be no small-diameter feeder pipes.

A better single-pipe system connects each unit separately to the loop with an individual take-off pipe and shut-off valve (see Figure 8.7). This allows individual regulating of each unit as well as control of the loop, as in the series connected system. Special fittings are required to keep the water running in the proper direction and to induce flow into the radiators.

Fig 8.7 Single-Pipe Individual Take-Off Hot-Water System: Looking up at the area of the basement ceiling that's directly under the first-floor radiators, one wide-diameter pipe will be seen under each radiator. Each of these pipes will be connected to its radiator by two smaller feeder pipes.

above: one-pipe return tee fitting

The best system is a two-pipe reverse-return system where one pipe delivers the hot water and another returns it to the furnace (see Figure 8.8). To take maximum advantage of a two-pipe system, it must be set up so that the first radiator to receive the warm water is the last radiator on the return line. This is called a reverse-flow system.

FIGURE 8.8 Two-Pipe Reverse-Return Hot-Water System: Looking up at the part of the basement ceiling that's directly under the first-floor radiators, two wide-diameter pipes will be seen under each radiator. Each will be connected to its radiator by a smaller feeder pipe.

A hot-water system generally uses radiators, baseboard panels or convectors to distribute the heat into the room (see Figure 8.9). These three units depend on both convection (air being warmed as it passes over the heated metal and then circulating into the room) and radiation (heat waves being transferred directly from the heated metal to the object being heated by radiant energy). There also are combination systems in which the heat is brought to the radiator by warm water. A fan in the radiator blows air over the radiator fins, heating rooms by convection.

Fig 8.9 Types of Radiators: one and two-pipe steam—cast-iron radiator; two-pipe steam—cast-iron radiator; baseboard convector

A radiant heating system depends solely on the direct transfer of heat by radiation from the hot metal to the object being heated. The heated water is pumped through coils of pipe that are embedded in the floor, walls or ceiling or some combination of these. This system is particularly adaptable to slab construction where the coils are embedded in the slab. A major advantage is the absence of visible radiators or baseboards. A disadvantage is slow response to changing weather or other conditions affecting the temperature of the room.

A hot-water system can be expanded to perform other functions, from melting ice and snow in the sidewalks and /or driveway to heating an indoor or outdoor swimming pool or greenhouse.

Steam Heating System

Steam heat is produced by a furnace that's a boiler with a firebox underneath it. The water in the boiler boils, making steam that's forced by its pressure through pipes into the radiators throughout the house. In a single-pipe system, the steam cools, turns back into water and runs back to the furnace to repeat the cycle. In a two-pipe system, it returns via a separate pipe.

A two-pipe system tends to be less noisy than a one-pipe system. Noise is a disadvantage inherent to all steam systems. Another disadvantage is the difficulty in controlling the heat when only small amounts are needed.

Electric Heating System

When electricity is used in the same way as oil, gas or coal to heat the air in a hot-air furnace or the water in a hot-water furnace, it can be thought of as just another fuel. What makes it unique in house heating is its use with resistance elements that produce heat at the immediate area to be heated.

Electric resistance elements, which convert electricity into heat, are embedded in the floors, walls and ceilings to provide radiant heat. They are embedded at the time of construction or may be factory-installed in the building materials. The advantages of electric radiant heat are the lack of visible radiators or grilles and the comfort obtained without heating the room air hot enough to drive out the moisture. Its acceptance by the public isn't universal and substantial experimentation still is being conducted by the manufacturers and others. Electric heat has the potential, however, of being a very satisfactory heating system because base board radiators with individual resistance elements are inexpensive to install compared to other systems. Electric heat also provides the advantage of individual temperature control for each room.

Electric heating panels, also with individual resistance elements, of ten are used for auxiliary heat in bathrooms, additions to the original house and summer homes.

The heat-pump electric system provides both heating and cooling from a central system. It actually is a reversible refrigeration unit. In the winter, it takes heat from the outside air, ground or well water and distributes it in the house. Its efficiency decreases when it's very cold out side and it must be supplemented with resistance heating. In the summer, the system cools by extracting heat from the inside of the house like a typical air-conditioning unit. This modern heating and cooling system still constitutes a small percentage of the systems being installed. It is increasing in popularity, however, and may turn out to be the system of the future.

Solar Heat

Solar heat still is in the experimental stages. With it, the sun’s heat is collected and used to heat water, which, in turn, is pumped throughout the house to provide heat. (See the “Fuels” section in this section.)

Heat Controls

All of the systems previously described can be operated by simple, automatic controls.

The first control one thinks of is the thermostat, which is designed to turn the system on and off to produce heat only when it's needed or route heat to the areas where it's needed. A thermostat is a temperature sensitive switch. While a thermostat often controls the heat in more than one room, it can read the temperature only at the point where it's located. Therefore, it must be located at a spot typical of the area being regulated.

Different heating systems allow various levels of control, ranging from some electric systems that control each room individually to steam, hydronic and air systems with only one control zone for the entire house. It is best to place the thermostat 2 to 4 feet from the floor. Common mis takes are to place it too high or to put a lamp, radio or TV near it.

More sophisticated thermostats contain a device, called an anticipator, which shuts off the heating shortly before the desired temperature is reached. Because the system does not cool off instantly, the room will be brought to the desired temperature. Thermostats that automatically lower the heat during the sleeping hours also are available. In many houses, this will result in fuel savings. In some houses, it's just as economical to leave the heat at a constant temperature. Many people think that if they turn a thermostat up higher than the desired temperature, a room will warm up faster. Because a thermostat only turns the heat on or off and does not control the timing of temperature changes, however, this isn't true.

When it's very cold outside, additional comfort may be obtained by setting the temperature a few degrees higher than usual to compensate for the increased body-heat loss by radiation to the cold outside walls. This also compensates for the tendency of thermostats with anticipators in them to run a few degrees colder under these conditions.


Dry air in the winter can be a problem with all types of heating systems, contrary to the popular misconception that it's a warm-air heating deficiency. The major controlling factor is the construction of the house. Moisture is generated by the activities of daily living, such as cooking and bathing, and is drawn out of the house in the winter to the dry air outside through leaks and cracks. A tight, very well-insulated house will retain enough moisture for comfortable living, which is about 25-percent to 30- % relative humidity.

A dry-air problem can be corrected by adding a humidifying device to a hot-air heating system or with portable humidifying devices. Often a small vaporizer in the bedroom at night will solve the problem.

Occasionally, in a super-insulated, electrically heated house, the re verse problem will develop, resulting in wet walls and windows. In this case, an exhaust fan connected to a humidistat control will effectively control the humidity.

Poor Heating

The major causes of poor heating are insufficient insulation and an in adequate or poorly functioning heating system. Insulation often may be added, and storm windows and weather-stripping.

The condition of the furnace usually is reflected in its appearance. An old furnace encased in asbestos probably is going to cause trouble. An adequate-sized, clean furnace without rust may require minor repairs, but usually it has plenty of good life left in it.

A free or nominally priced inspection of the heating system often is available from the fuel suppliers in the area. Fuel costs may be checked by asking for a year’s bills from the homeowner or fuel supplier. Fuel costs can vary considerably according to the habits of the residents.

The performance of many furnaces can be improved by a good cleaning, adjustment and replacement of clogged air filters.


Hot Water from the Furnace

Hot water may be made in a hot-water or steam furnace by installing a coil in the boiler. A storage tank may, optionally, be added to the system. This type of system, called a “summer-winter hookup” in some parts of the country, provides a steady, small supply of hot water that may be exhausted by too much use at one time. Another disadvantage is the need to run the furnace year-round. The recovery rate is fast, however, and the hot water will shortly replenish itself when exhausted.

Electric Hot-Water Heaters

There are two basic types of electric hot-water heaters. The “quick recovery” type has one or two heating elements that turn on as the water is used and bring the water temperature in the tank up, starting immediately after it's lowered. In some areas, an “off-peak” system is used. The tank produces most of the hot water during the night when the electric rates are low and makes hot water during the day only when the night- produced supply has been exhausted.

One-element and two-element “quick-recovery” tanks range in size from 30 gallons, suitable only for one or two people who use a limited amount of hot water, to the more popular 66-gallon and 82-gallon sizes. Most of the off-peak tanks are the 82-gallon size.

Gas Hot-Water Heaters

Gas hot-water tanks range in size from 30 to 82 gallons. Gas produces a faster recovery rate than electricity, so a slightly smaller tank than would be required for electric heat can be used. The cost per gallon of gas hot- water tanks of similar quality is higher, however, so the difference be comes academic. A 30-gallon or 40-gallon tank is suitable only for one or two people whose use of hot water is limited. The more popular sizes are the 52-gallon and 82-gallon sizes.

Oil Hot-Water Heaters

The recovery rate of an oil hot-water heater is very fast, compared to gas or electricity. Because of this, a 30-gallon tank will provide enough hot water for the needs of most families. The operating cost in most areas is less than gas or electricity. What limits the popularity of oil hot-water heaters is their initial high cost and high installation expense. This is especially true if there is no flue and oil storage tank already available.

The length of the pipe from the source of the hot water to the fixture should be less than 15 feet. Longer pipes cause a great deal of heat loss and the water must be run for a while before it becomes warm. This can be partially corrected by insulating the hot-water pipe. Also, it's possible, to install a return system from the fixture to the hot-water source, which provides a continuous circulation of water from the heater to the fixture and back to the heater. Sometimes, in larger houses, the best way to keep the pipes short is to install two tanks.

The final selection of a hot-water heating process usually is based on the relative fuel cost in the area. Using the same fuel that the heating system uses often results in a lower overall rate (especially if the cooking appliances also use the same fuel).

Because nothing is more annoying than the lack of hot water when it's needed, care should be exercised in selecting a system that's adequate for the family’s needs. Utility companies have recognized the problem and offer a practical solution to inadequate hot water by making available tanks that are rented from the utility company and paid for along with the utility bill.


War has broken out between the purveyors of heating fuels, each pro claiming the merits of his or her own product and the disadvantages of the competitors’ products. Each fuel has its own significant advantages and disadvantages that must be considered against individual needs and preferences and then weighed against the relative costs in each area.

The ideal time to select a heating system, of course, is before the house is built. It rarely pays to tear out an existing, working system and replace it. Often, however, it does pay to rebuild or repair a system to bring it up to peak efficiency. If the furnace needs to be replaced, consideration might be given to changing fuels.

Despite advertising claims to the contrary, natural gas, liquid petroleum (LP), gas, fuel oil and electricity are all about equally safe and clean. Coke and coal are definitely dirtier. Except when these fuels are used, the extent of safety and cleanliness is governed by the condition of the heating system itself. With the exception of a few isolated areas of the country, coal and coke rarely are used in new systems for residential heating. In general, systems using them as fuel are fast becoming obsolete.

Fuel Oil

Oil is still the least expensive fuel in the northeast and northwest sections of the country and is competitive in many other sections. It may be stored in the basement of the house in one or two freestanding tanks not more than 275 gallons in size (larger tanks and more than two tanks in a basement are considered unsafe). Outside tanks buried in the ground commonly have 550-gallon or 1,000-gallon capacities. Many oil companies offer automatic delivery, regulated by a system of measuring the degree days of heat required, that virtually ensures a continuous supply with a reserve in the event of interrupted supply. The larger the storage tank, the less the per-gallon cost of the oil. New kinds of burners have increased the potential efficiency, but they are more complex than gas burners, re quire more maintenance and have a shorter life expectancy. Oil tanks re quire maintenance and periodic replacement and take up living space in the basement.

The price of oil tends to fluctuate substantially throughout the sea son. The new laws requiring the use of only low-sulfur fuel in many areas have raised the price. The construction of more supertankers and the changing world political situation, however, eventually may produce price reductions.

Natural Gas

Natural gas offers the convenience of continuous delivery via a pipeline without the necessity of storage tanks. Many suppliers offer lower rates if the hot-water heater and cooking ranges also use gas. A gas furnace and burner is less complex than an oil furnace and burner. It requires less maintenance and has a longer life expectancy. It needs no on-site storage, but in the event of a supply interruption, there is no reserve supply. In most areas of the country (the major exceptions being the Northeast and Northwest), gas is the most economical fuel.

Liquid Petroleum Gas

Liquid Petroleum (LP) gas is used in rural areas. It requires on-premise storage tanks and usually is more expensive than natural pipeline gas. In other respects, it's similar to natural gas.


Electricity appears to be the fuel of the future. It requires no on-premise fuel storage and can be used like coal, gas or oil to heat air in a hot-air furnace or water in a hot-water furnace or water heater. When used with resistance units at the area to be heated, it's unique. This system is the least expensive to install, for it requires no furnace, no furnace room, no ducts, no flue and no plumbing.

It does require, however, a much larger electric service into the house and wiring to each unit. When used in colder climates, special care in construction is required to eliminate air leaks and provide sufficient insulation. The disadvantage of this system in that there is no emergency on- site supply. Electric-resistance heating systems and heat-pump systems are unquestionably the most versatile, convenient and controllable systems. To date, despite advertising to the contrary, electric heat costs re main high except in lower-cost power areas.

Solar Energy

The basic principles of most solar systems developed so far are similar. The sun’s energy is collected with an array of pipes or flat metal sheets that are painted, coated, plated or otherwise treated to increase their ability to absorb heat. Often they are encased in glass or plastic and positioned to catch the maximum amount of sun.

Air, water or other chemical mixtures in the piping collect the heat and distribute it either through a standard heating system or one that has been modified for solar energy use. Sometimes the heated water is pumped into a storage area for use when no sunlight is available.

Comparison of Fuel Costs

One does not have to be a mathematical genius to calculate the relative cost of fuel. Because there is so much confusion on this subject, it seems worthwhile to provide instructions on how to make the comparison.

Because it's impossible to compare directly the cost of one fuel against the cost of another, it's necessary to first find some common de nominator to use as a unit of comparison. Heat is measured in units called calories or therms. These units are so small, however, that they are hard to use. A bigger unit was developed called a British Thermal Unit, the BTU. This is the amount of heat that it takes to raise the temperature of one pound of water one degree Fahrenheit. This still is a very small amount of heat. In home heating, the cost per million BTUs is the standard measurement used.

To compare the cost of fuel, the cost of making a million BTUs with each kind of fuel in a specific area must be determined. Once the relative costs of the fuels are known, these can be weighed against the other ad vantages and disadvantages of each type of system and a final selection can be made. Following are the steps involved in calculating the costs of the different fuels.

Fuel-Oil Cost Calculation

Step 1. Estimate the efficiency with which a residential fuel-oil furnace will convert a number-2 oW (the most common type used in house heating) into heat. The efficiency ranges from about 50 % for an older converted furnace to 80 % for a new, properly adjusted furnace. Most major oil retailers will perform an efficiency test on a furnace at no or nominal cost. If no such test is made, however, make an estimate for an existing furnace or use 80 % .

Step 2. Obtain the price of fuel oil in the area. Use an average price, taking into consideration seasonal fluctuations. Do not be afraid to ask for a discount; they are a common practice in many areas. Also, check the saving offered by installing a larger tank. The conclusion may be that its installation soon will pay for itself.

Step 3. Calculate the cost to produce a million BTUs of heat. Multiply the oil cost per gallon by a factor of 7.15 and then divide by the system’s efficiency percentage. Example: if the oil cost is 80 cents and the furnace tests at 60-percent efficiency:

.80 x 7.15 / .60 = $9.53 per million BTUs

Natural-Gas Cost Calculation

Step 1. Estimate the efficiency of the gas furnace to convert gas into heat. The efficiency ranges from about 60 % for an older, converted furnace to 80 % for a new, properly adjusted furnace.

The gas company usually will make an efficiency test at no charge and at the same time offer recommendations to increase the system’s efficiency.

Step 2. Obtain the price of gas in the area. If it's not published in therms, ask the gas company for the price per therm. If the rate is on a sliding scale, ask for the typical average rate for a one-family house.

Step 3. Calculate the cost to produce a million BTUs of heat by multi plying the gas cost per therm by a factor of 10 and then dividing by the system’s efficiency percentage. Example: if the gas cost is 40 cents per therm and the furnace tests at 60-percent efficiency:

.40 x 10 / .60 = $6.66 per million BTUs

The same formula can be used for bottled liquid petroleum (LP) gas.

Electric-Heat Cost Calculation

Step 1. The efficiency of an electric baseboard system is close to 100 % because it converts all the electricity into heat and there is no flue through which the heat can escape.

Step 2. Obtain the price of electricity in the area (be certain this is the residential heating rate). Also check for a possible rate reduction by converting the hot-water heater and stoves to electricity.

Step 3. Calculate the cost to produce a million BTUs of heat by multi plying the electricity cost per kilowatt hour by a factor of 293 and then dividing by 100. Example: if electricity costs $2.00 per kilowatt hour:

2.00 x 293 / 100 = $5.86 per million BTUs


A few attempts were made during the late 1800s to cool houses, but little was effectively accomplished other than moving the air around with fans until after World War II.


Fans still are an accepted method of cooling. The air inside the house may be cooler than the outside air yet may feel warmer because of the lack of air movement. A simple room fan (especially when the temperature and humidity aren't too high) often will make the room seem much cooler. The fan in a warm-air heating system may be used to move the air and to bring cooler basement air up into the house. (Again, this works best when the temperature and humidity aren't too high.)

An attic ventilation fan cools in several ways. During the day, it re moves the hot air from the attic, which when left in place soon seeps down into the house, substantially raising the overall interior temperature. For best results, the attic fan should be large enough to remove air equal to the volume of the house every minute. E.g., a house that's 10,000 cubic feet should have an attic fan rated to remove 10,000 cubic feet of air per minute.

In many areas of the country, the outside air temperature drops sharply during the night. The attic fan is used to replace the hot daytime air with cool night air. In some areas of the country, a timing device is needed to turn off the fan to prevent the house from overcooling. If the house is well insulated and kept closed during the following day, the in side air may remain substantially lower than the hot outside air.

Window exhaust fans work on the same principle as attic fans. They are especially effective in changing cool night air for hot daytime air in bedrooms and living areas.

Evaporation Cooling

In some areas of the West, the humidity is low most of the time, even during periods of high heat. In these places, a simple system of blowing air across wet excelsior or some other water-absorbing material will cool the air substantially. What happens is that the water evaporates and , in the process, cools the air. Package units are manufactured for home installation in windows. They are simple machines and are less expensive than conventional air-conditioning.

Air-Conditioning Principles

With the exception of fans and evaporation cooling, most house air- conditioning uses either electric-power compressor-cycle equipment or gas absorption-cycle equipment. These are the same two types of systems used in household refrigerators. The basic law of physics that applies to both types is that when a liquid is changed to a vapor or gas, heat is absorbed and when the vapor is compressed back into a liquid, the heat it previously absorbed is given off.

In an electric system, the refrigerant that's changed back and forth from gas to liquid usually is Freon. The equipment consists of a device that compresses the Freon into liquid inside an arrangement of finned tubes that are located outside the area to be cooled (usually outside the house). As the Freon is compressed in these tubes, they become hot. The heat is disbursed by either running water over the tubes in a water-cooled unit or more often by blowing outside air over them with a fan.

The liquid then is run through a pipe to another set of thin tubes in side the room to be cooled. The liquid is allowed to expand back into gas inside these tubes, which become cold and absorb heat from the room air that's blown over them with another fan. Moisture in the air will con dense on the fins and tubes and drip off and must be drained away. This also reduces the humidity in the air, which, for human comfort, is just as important as temperature reduction. The gas then is pumped into the compressor and the cycle repeats itself. The condensation tubes and evaporation tubes can be close together as they are in room window and sleeve units or separated and connected by two insulated tubes as they are in most central air-conditioning systems.

In a gas-powered absorption-cycle system, ammonia often is used as the refrigerant with water as the absorbent or water is used as the refrigerant and a lithium-bromide solution as the absorbent. Instead of a compressor, there is a generator where heat is applied in the form of a gas flame and the refrigerant is boiled out of the absorbent; it passes in gas form into the condenser under high pressure caused by the boiling in the generator. Here it's cooled by passing outside air or water over it and it condenses back into liquid while still remaining under pressure. From the condenser, it goes through a metering valve into the evaporator tubes located in the room to be cooled. It expands in the evaporator, absorbs heat and condenses moisture from the air in the room. As an alternate, the expanding refrigerant can be used to cool water that has been pumped into coils or convectors in the room. The refrigerant, now in vapor form, passes on to the absorber where it forms the solution that's pumped back into the generator.

Electric Room Air-Conditioning Units

Millions of room compressor-cycle air-conditioning units are being manufactured and sold in this country each year. They now provide an economical solution to summer heat. Their main disadvantages are their ugliness, their high noise level and the fact that they are a haphazard solution to complete year-round home temperature control. On the other hand, if the family budget does not permit a central air-conditioning system, air-conditioning units provide a good deal of comfort for their relatively low cost.

Widely available are 4,000-BTU and 5,000-BTU units that can be carried home from the store and installed by many only moderately handy homeowners without the help of an electrician. These units run on 110 volts and use so little electricity that they can be plugged into a regular wall outlet in most homes with modern wiring. They will nicely cool a small room in many climates.

Larger room air conditioners range upward in size from the popular 8,000 to 12,000 BTUs to as high as 35,000 BTUs. These units generally re quire 220 volts and should be installed on their own separate electric line with a built-in ground wire.

The most common place to install a room air-conditioning unit is in the bottom half of a double-hung window. The window is secured tightly shut against the unit and the cracks plugged up with special felt and boards usually supplied with the unit. Specially shaped units also are made for installation in casement windows and through wall sleeves. The advantages of sleeves compared to window installations are that sleeve units don't obstruct window vision, tend to be more permanent and may be placed high on the wall for more efficient air distribution. If there is a choice of windows or walls, the units should be installed on the north or east side of the house.

Ducted Central Air-Conditioning Systems

These systems can be custom made or can be prewired, pre-charged factory-assembled packages that are connected at the home site. The con denser portion is set outside the house on the ground or on the roof. It is connected by pipe to the evaporator air-handling unit. The air-handling unit, consisting of the evaporator and a fan, is located inside the house and is connected to a system of ducts that distributes the cool air throughout the areas of the house to be cooled. If the house has a warm forced-air heating system, the air-conditioning system can use the same fan, filter and duct system. The ducts of the warm-air system, however, may not be suitable for air-conditioning because cooling generally re quires double the duct size as heating and the cooling system works much better if the registers are high on the wall or are the type that directs the air steeply upward.

A hydronic heating system also can be combined with a cooling system. A water chiller is coupled to the boiler to supply cold water to a special type of convector that has been placed in each room as a replacement for the old-style radiator. The conversion of old-style hydronic systems to combination systems often is so costly that it's less expensive to install a separate new set of air-conditioning ducts.

Heat-Pump Systems

The heat pump is a reversible heating and cooling system (see Figure 8.10). It both heats and cools the house but works best in climates where the winters aren't very cold. This system has been described previously in the electric heating section of this section.

Fig 8.10 Heat Pump


Plumbing is like an iceberg—only a small part of it's visible. There has been plumbing of a sort in houses for more than 2,000 years. Emphasis gradually shifted from running water used for washing and cooking to all kinds of bathing devices and finally to the inside toilet. Probably the biggest difference between houses being built today and those built prior to World War I is the plumbing system. The plumbing systems in many of these pre-World War I houses, however, now have been completely modernized. The old-style plumbing fixtures are becoming so rare that many are being sold as antiques.

The best way to cut through the mystery that exists in the minds of so many when it comes to plumbing is to discuss it in its various parts rather than as an incomprehensible whole system.

First, municipal water supplies and wells, water pumps, water softeners and water pipes will be discussed. Then the bathroom, kitchen and other fixtures in which water is used will be covered, as well as methods of removing the water from the fixtures through waste pipes to the sewer, septic tank or cesspool. Figure 8.11 shows how each component might fit in the larger system.

Fig 8.11 Plumbing System

Technically, parts of the heating, hot-water and air-conditioning systems also are plumbing. For ease of understanding, however, they are discussed separately in this guide.

Water Supply

Both common sense and the MPS require that when a public water sup ply is available, it should be used. An attempt to save money by using a well when this isn't necessary is an economy made at the possible expense of the family’s health.

In the absence of available public water, the next best supply is a well that's dug on the lot and water from it pumped into the house. Some houses obtain water from rivers, streams, lakes and even rainwater collected from the roof and stored in tanks. None of these latter systems are considered satisfactory water supplies, however, for they don't provide a sufficient quantity of dependably pure water.

Water supplied by a public water system must meet the purity standards of local health officials. Water usually is piped in the streets in water mains. A copper pipe of at least 3 diameter taps into this line and runs underground into the house. Instead of copper, 1-inch to 1¼ inch galvanized iron pipe also may be used. There should be a cut-off valve at the street edge to shut off the water in an emergency. This usually is found in a hole covered with a steel or iron plate. Another cut-off valve for the same purpose should be located where the pipe enters the house. The pipe shouldn't be run where it's likely to be disturbed, such as under the driveway. When the pressure in the water main is more than 80 pounds per square inch (psi), it's necessary to install a special valve to reduce the pressure in the house to below 80 pounds to prevent damage to the plumbing system. A water meter generally is installed right after the in-house emergency cut-off valve and often another cut-off valve is in stalled on the other side of the meter as well. In some older communities, the water company sells water at a flat rate or at so much per fixture rather than by metering it.

As the MPS states, “A well shall be capable of delivering a sustained flow of 5 gallons per minute. The water quality shall meet the chemical and bacteriological requirements of the health authority having jurisdiction.” Generally, except in arctic conditions, the well should be located outside the building foundation at a minimum depth of 20 feet. It should be located at least 100 feet from an absorption field or seepage pit and 50 feet from a septic tank. Bored wells should be lined.

An artesian well is a well that's drilled through impermeable strata, deep enough to reach water that's capable of rising to the surface by internal hydrostatic pressure. This type of well still requires a pump to pro duce enough pressure for household use. The only way to be sure a well meets these important standards is to have it tested professionally.

There are two basic types of well pumps, the submergible pump located inside the well and the basement pump. The pump capacity shouldn't exceed the flow rate of the well or it will drain it and bring up dirt. At least a 42-gallon storage tank is needed to provide a smooth flow of water.

Water Pipes

The water pipes must carry water throughout the house to the various fixtures without leaking, making noise, reducing the pressure or imparting any color or taste to the water.

Brass has been used for many years, but now it's expensive. Older brass pipes tend to crystallize and become coated on the inside in areas where the water is corrosive. Brass is easily worked, however, and generally is installed by threading the ends and screwing them into joints.

Galvanized steel is used in some areas. It is, however, easily attacked by corrosive water. Like brass, it's easily worked and is connected with threaded joints and fittings. Galvanized wrought iron is similar to steel but is more resistant to corrosion.

Copper is available as rigid pipe and flexible tubing. In many areas, it's the only acceptable material. Joints are made by soldering copper joints to both pipe ends. In some areas, mechanical joiners can be used. Lead used to be a popular material. It still is used for the pipe from the water main to the house in some areas but rarely is used inside the house.

Plastics are the newest material used for pipes. The manufacturers claim and many builders agree that plastic is as good as any other material and may indeed be better. It is gaining acceptance although its use still isn't permitted in many cities.

Water Softeners

In many areas of the country, especially where water is obtained from deep wells, large amounts of calcium, magnesium, sulphates, bicarbonates, iron or sulfur often are found in the water. These minerals react unfavorably with soap, forming a curd-like substance that's difficult to rinse from clothes, hair and skin. The bicarbonates, when heated, form a crust inside pipes and cooking utensils and a ring in the bathtub. Iron will stain clothing and sulfur makes the water taste and smell bad.

The simplest water softener is a manual shingle tank that's connected to the water line. Inside the tank is a mineral called zeolite that exchanges the offensive minerals in the water for sodium chloride (common salt). The zeolite must be poured into the tank. In a typical area with nor mal water use, salt must be added and the zeolite flushed out about twice a week. Also available is a two-tank automatic unit that will add the salt and flush the zeolite automatically. Of course, salt still has to be fed into the second tank every month or so. The zeolite is best at removing the calcium and magnesium. If the amount of iron, sulfur and other minerals still is very high, a third tank with special filters and chemicals may be needed for the complete removal of these materials.

Plumbing Fixtures

The parts of the plumbing system that compare to the above-water portion of an iceberg are the fixtures. Bathroom fixtures consist of lavatories, washbasins, bathtubs, showers, toilets (also know as water closets in the plumbing trade) and , occasionally, bidets.

Kitchen fixtures consist of sinks, laundry sinks, dishwashers and garbage disposals. Other areas of the house may contain additional laundry tubs, sinks, bar sinks, outside sill cocks and other specialized fixtures.

Technically, hot-water heaters and hot-water heating systems may be considered part of the plumbing system and fixtures, but they are discussed separately in this guide.

Washbasins (Lavatories)

The most satisfactory way to install a washbasin is to set it into a vanity counter. This provides the much-needed space alongside the basin on which to stand beauty aids, shaving equipment or toothbrushes.

Counter-mounted lavatories are available in four basic types. The flush mount requires a metal ring or frame to hold it in place. Although this type is very popular and inexpensive, dirt tends to collect around the edges of its rim. The self-rimming style eliminates this dirt-collection problem on the basin side of the rim but not on the counter side. A hand some effect can be obtained with an under-the-counter lavatory when used with a countertop that's or looks like marble. The seam where the lavatory meets the underside of the counter, however, is likely to collect dirt and is difficult to clean. The newest style is a lavatory that's an integral part of the countertop, making cleaning very easy. Wall-hung lavatories are available in several models. Generally, they are installed as an economy measure or where space is at a premium.

Basins are made of the same materials as tubs and these materials have the same advantages and disadvantages as when they are used for tubs. The most common satisfactory material is cast iron covered with acid-resistant vitreous enamel. The product of the future is a fiberglass basin molded together with the vanity countertop.

The size of the basin is important (see Figure 8.12). For a bathroom, an 18-inch-wide basin is the minimum standard. Larger sizes range from 20 inches to 28 inches to 30 inches in luxury models. Fifteen inches is a minimum satisfactory depth, but 18 to 20 inches is better. If there is no imprint of a national manufacturer under the basin, the fixture may be a second or the lowest grade.


The bathtub is the most expensive fixture in the bathroom and builders often are tempted to economize with it. Four different materials generally are used for tub construction.

Ceramic-tile tubs are built in place usually at the same time as the ceramic walls and floors are laid. These tubs are expensive and uncommon. They require skilled craftsmanship for proper installation and are prone to leaking unless perfectly constructed.

By far the most common type of tub is made of cast iron coated with enamel. The cheaper grades are coated with regular enamel and the better grades with acid-resisting enamel. Unfortunately, it's very difficult to tell by looking what type of enamel has been used, except that most colored tubs are the acid-resistant type.

Steel tubs covered with vitreous enamel are less expensive than cast- iron tubs. The problem with them is that they are less rigid and more likely to crack. They can be identified by tapping and listening for the less-solid sound or by pressing the bottom, which often will be springy.

Fiberglass is gaining in popularity and well may be the product of the future for bathtubs. It is light and often is cast in one piece in conjunction with the wall, thus making the tub easy to clean and waterproof at the edge joining the wall. The finish, however, isn't quite so hard as vitreous enamel and is more susceptible to scratches.

The most common tub is 5 feet long and 14 to 15 inches deep (see Figure 8.12). Even a few inches difference in depth, however, makes a big difference in comfort, as does 6 inches of extra length. Therefore, there is a big comfort difference between a standard 5-foot, 14-inch deep tub and a 5 16-inch tub. The cost difference is about $50.

Fig 8.12 Bathroom Fixture Sizes: tub sizes; shower stall sizes; lavatory sizes

Sunken tubs are status symbols that appeal to some people. The prestige of these tubs must be weighed against their hazardous nature and the backbreaking chore of bathing children in them. Square tubs are useful in certain layouts and will provide more tub area than a regular tub in the same spot.

The imprint of the name of the national manufacturer stamped on each fixture should be checked because a fixture without a name stamped on it often is the lowest grade or a second. In general, a cast-iron tub is better than steel.

The best grade of tub fixtures is solid brass coated with chrome, nickel or brushed or polished brass. Most good-grade fixtures have solid handles with grooves for fingers. Poor-grade faucets are zinc or aluminum castings and often have cross-shaped handles.

Tub-Shower Combinations

By far the most popular shower arrangement is to have the shower located over the end of the tub. This arrangement costs little more than to install the tub alone because the cost of a separate shower enclosure is eliminated. This saving is mostly lost, however, if there is a sliding-glass (or translucent-plastic) shower enclosure installed on the edge of the tub. A shower rod and curtain is much less expensive and preferred by many who don't like the closed-in feeling of the glass enclosure or the difficulty of keeping it clean. A shower rod with a double curtain works quite satisfactorily for many families.

Showers and Stall Showers

A separate shower stall is a troublesome, expensive luxury that many people feel still is worthwhile. This stall usually is located in the master bed room. A popular type of construction includes a floor pan of concrete covered with ceramic tile, walls covered with ceramic tiles and a glass door. Anything but a one-piece floor pan eventually will leak and other wall coverings rarely work.

A less-expensive prefabricated steel model also is commonly used. Its floor pan also is a one-piece concrete pan and its walls are painted steel or galvanized iron. The door usually is open with a rod for a curtain. These units are quite satisfactory although not very luxurious in appearance.

The newest product is a one-piece fiberglass stall. These are attractive, come in many shapes, often eliminate the need for a shower curtain and are reported to be quite satisfactory. Cleaning the ceramic tile and steel models is difficult and time-consuming, but the fiberglass model cleans easily.

Leakage usually takes place through the walls, at the joint between the wall and floor pan and around the seam at the edge of the floor pan and drain. In new houses, it's impossible to tell by inspection if the shower will leak, so a good builder’s guarantee is important. In older houses, inspection of the ceiling under the shower usually will show tell tale marks of any leaking. New painting or papering in this area may be suspect as it may have been done to hide leak marks. Ceramic-tile walls are most susceptible to leaking, but this problem is less likely with steel and is unlikely with fiberglass. Ceramic-tile showers and steel showers both may leak at the wall-pan joint. This is unlikely with fiberglass. All types of stall showers may leak at the pan-drain joint.


The design and quality of the toilet is more important than the other fixtures because the tub and lavatory primarily hold water while the toilet is a much more sophisticated mechanism. Most residential toilets consist of a bowl and tank that stores enough water to create a proper flushing action. There is another type of toilet, often found in commercial buildings, that does not require a tank. Few houses have sufficiently large pipes or water pressure for this tank-less type, however. Figure 8.13 shows common toilet types.

fig. 8.13 toilet types: wall-hung siphon jet; low profile siphon action; wash-down; reverse trap; siphon jet

Briefly, what happens when the flush lever on a toilet is depressed is that it lifts a plug off an opening in the bottom of the tank and the water flows into the flushing unit. As the water flows out of the tank, a large air-filled metal ball, which is called a float and is attached to a valve by a metal arm, drops down, opening the valve to let fresh water into the tank. As the tank refills, the float rises, and when the water reaches the correct level (as indicated by a line inside the tank), the valve is turned off.

There also is a standpipe (overflow) next to the valve with a small pipe emptying into the top of it. After the toilet has been flushed, water continues to flow from the small tube into the bowl, filling it again to the correct level. The standpipe also serves as an overflow protection in case the valve fails to shut off.

The quality of a toilet is judged by its performance in the following areas: self-cleaning properties, free rapid-flushing action, quiet during flushing action and ease of cleaning around exterior.

There are four basic types of toilets, practically all of which now are made of vitreous china.

The wash-down bowl type of toilet is an inferior product that's used only to save money. It is flushed by a simple washout action. The interior water level is very low, making the bowl subject to fouling, staining and contamination. Its flushing action is noisy and its self-cleaning proper ties are poor. It can be recognized by its almost round shape and its straight-line profile in front.

The majority of toilets currently made are the reverse-trap bowl type. The inside water level covers about two-thirds of the interior surface. It is flushed by creating a siphon action in the trapway, assisted by a water jet located at the inlet to the trapway. This siphon action pulls the waste from the bowl. Its self-cleaning characteristics and flushing action are quite satisfactory but moderately noisy. The reverse-trap bowl toilet is only slightly more expensive than a wash-down type and is a much better buy.

An improved version of the reverse-trap toilet is a siphon jet. This type covers a larger surface of the bowl with water. The trapway is larger and thus less subject to clogging and noise during the flushing action.

A still better siphon jet is the wall-hung model that makes cleaning easy around the toilet area. Because this model is suspended from the wall in the back and does not touch the floor, the wall studs to which it's fastened must be specially braced. Unfortunately, this toilet costs substantially more to install and usually is found only in custom-built homes.

The most luxurious toilets are the one-piece, low-profile, siphon- action toilets. They provide almost silent flushing action, almost no dry interior bowl surface and therefore excellent self-cleaning action.

One can easily test each toilet in a house by throwing in a piece of crumpled facial tissue or toilet paper and flushing the toilet. The water should flow swiftly over all of the interior wall, thereby performing a self-cleaning action, and the noise shouldn't be excessive. Watch how quickly and surely the paper goes down. Watch and listen to the refilling action to determine if it's quick and quiet.


Bidets are standard fixtures in Continental baths. In America, they are rare but slowly are gaining popularity. They usually are installed by people of European background or by those who travel to Europe often or more likely as a status symbol or conversation piece.

The bidet is perhaps the most misunderstood bathroom fixture. Many people incorrectly believe that the bidet is used for internal feminine hygiene. Actually, it's used by the entire family to wash the perineal area after using the toilet. A pop-up stopper holds water in the basin while washing. A spray is provided for rinsing and a flushing rim serves to rinse the entire inner surface of the bowl after using the bidet.

Bathroom Fittings

Fittings include faucets, spigots, shower heads, pop-up drains—the working parts of the plumbing system. These will require repair and replacement many times during the life of a house.

A faucet controls the flow of water into the fixture and often is designed to mix hot and cold water. The most common type of arrangement is two separate valves, one each for the hot and the cold water. In older or in very cheap installations, there is a separate spout for each valve, too. Most faucets now being installed feed into a single spout, but each handle is turned separately to control the water temperature.

A better arrangement is a single control valve feeding through one spout. The temperature of the water is controlled by moving a knob or lever to the right or left. Water volume is controlled by moving the same knob or lever in and out or backward and forward.

A pressure-balancing valve is most commonly found controlling a shower head. The water volume usually is preset and the user selects only the temperature by turning the valve handle. A pressure-sensing device adjusts the flow of hot or cold water to compensate for pressure changes, thus keeping the temperature even and safeguarding against scalding.

The ultimate is a thermostatic control valve that automatically senses the water temperature and adjusts the flow to maintain the pre-selected desired temperatures. This type of valve offers more precise temperature control than the pressure-balancing valve and it usually also permits control of the water volume as well.

Most manufacturers produce three grades of fittings. One way to spot the low grade is by the cross-shape or inexpensive-looking handles.

The best buy is the middle-grade, which usually has attractive rounded handles with contours for the fingers. Luxury-grade fixtures have elaborate handles and platings of such exotic materials as gold or brass.

A quality shower head swivels in any direction, has an adjustable spray-control handle and is self-cleaning. A shower should have an “automatic diverter control” that switches the flow of water back to the tub after each shower so that the next user will not accidentally get wet or scalded.

Kitchen Fixtures

Most kitchen sinks are installed in some type of countertop. This may be either a single-bowl or a double-bowl type set to have a drain board on one or both sides. Single-bowl sinks range in size from 12 by 12 to 20 by 24 inches and double-bowl sinks from 20 by 32 to 20 by 40 inches. The drain-board type has a drain board made of the same material as the sink rather than the countertop. A type seen more often in apartments is the combination sink and laundry tub that has one deep and one regular- depth sink. The deep sink has a removable cover that serves as a drain board when the sink is closed.

Kitchen sinks may be made of acid-resistant enameled cast iron, enameled steel, stainless steel or Monel metal. Most modern kitchen sinks have a combination faucet with a swing spout. A separate spray on a flexible tube also is very common.

The drain should have a removable crumb cup or, better, a combination crumb cup and stopper. Also available now is an attachment for a kitchen sink that provides boiling water instantly.

Though technically part of the plumbing system, a dishwasher really is a household appliance like the stove, refrigerator and washing machine.

The best place for a dishwasher is under a kitchen counter near the sink. Normally, it has to be connected by a plumber to the hot-water and cold- water pipelines and to the drain pipe. It also must be wired into the electrical system. These two installation expenses, plus cutting into the kitchen cabinets if the dishwasher is installed after the house is built, make installation costs quite high. Standard models come in front-loading and top-loading types. The front-loading type has the advantage of making the countertop available for other uses. Mobile dishwashers are available where permanent installation isn't possible or desired. Generally, however, their convenience isn't so great as those installed in the counter.

Waste-disposal devices are installed under the kitchen sink, connected to the drain. When filled with garbage and flooded with running water, their fast rotary action breaks up the garbage into particles small enough to go down the drain to the sewer or septic tank.

They are unquestionably a convenience, but they also present some problems. First, some cities will not permit their use because the local sewer plant can't handle the additional waste produced by them. Like wise, many septic systems can't handle the additional waste. The safety hazard of putting a hand into a running garbage disposal has been eliminated on some models that will not run without tops on them. Because this solution may cut down on the convenience of the disposal, many are wired to go on with a switch.

There still is much to be said for a laundry tub in the basement or laundry room even if there is an automatic washing machine and clothes dryer. The tub can be used for soaking clothes without tying up the washing machine. It also provides a good place to wash household articles, plants, paintbrushes and other supplies.

Laundry tubs are available in a wide range of sizes and materials. The most common are the one- and two-tub models made of enamel-covered cast iron on steel legs. With some styles, a countertop, which provides handy extra work space, can be installed.

Outside Sill Cock

An outside sill cock (or bibcock) is a water faucet on the outside of the house with a screw nose to which a hose can be connected. The MPS re quires a minimum of two per house. They should be located on opposite ends of the house. In areas subject to freezing, they should be the frost-proof type and should have individual shutoff valves inside the house so they can be drained and turned off for the winter months.


The biggest difference between waste pipes and water pipes is the lack of pressure in the waste-pipe system. The water pipe must be strong enough to contain the water pressure and does not have to depend on gravity to make the water flow to the fixture. Because there is no pressure in a waste drain line, the pipes must be slanted so that the waste will flow from each fixture through the main lines into the sewer or sewerage-disposal system. Generally, drain lines are much larger than water pipes. Pipes from the toilets must be 3 to 4 inches in diameter, from showers, 2 inches in diameter, and 1 1/2 inches in diameter from all other fixtures, according to the MPS.

The drainage system starts at each fixture with a curved pipe called a trap. A popular misconception is that the principal purpose of the trap is to catch objects that fall down the drain. The real purpose is to provide a water seal to prevent the seepage of sewer gas into the house. Some municipalities require a special trap to catch grease before it enters the sewer line.

Drainage lines that run horizontally are called branches and those that run vertically are called stacks. The pipes that receive the discharge from the toilets are called soil lines and those that receive the rest of the discharge are called waste lines. Vent pipes from each stack to the roof prevent the sewer gas from building up pressure in the system.

Pipes for the drainage system often are made of cast iron, copper, plastic, tile, brass, lead or fiber. Special fittings often are used, especially on the cast-iron pipes, that aid the flow of the sewage.

Defective Plumbing and Noises in the Plumbing System

Plumbing suffers from two major problems: leaking and clogging with rust and mineral deposits. Leaking can be detected by visual inspection. Old-style iron or steel pipes are much more likely to develop leaks than corrosion-resistant copper and bronze. Iron and steel pipes can be detected with a small magnet that will be attracted to an iron or steel pipe but not to a copper or bronze pipe.

Insufficient water pressure can be caused either by clogged pipes, an undersized water main from the street, low water pressure in the street main or problems in the well or plumbing system. Water pressure can be tested by turning on full all the faucets in the bathroom on the highest floor and then flushing the toilet. A substantial reduction of flow in the faucets is a sign of trouble and the system should be checked by a plumber to determine the cause and the cost to correct it.

Stains in the bathtub and lavatories are a sign of rusting pipes or unsoftened hard water. If hard water is suspected, a sample can be professionally tested by a firm selling water softeners. Such a firm also can recommend what equipment will be needed and can tell how much it will cost to provide soft water.

Leaks under sinks may be caused only by a loose washer but also may be caused by a cracked fixture.

If a high-pitched whistling sound occurs when the toilet is flushed, the valve in the toilet is closing too slowly. A simple adjustment by a plumber will eliminate the noise. A sucking sound when the water runs out of a fixture often is made by a siphoning action in the trap caused by improper venting of the waste stack. If unclogging the vent does not work, only a major change in the vent system will eliminate the noise.

A hammering noise in the water pipes when the water is turned off is caused by a buildup of pressure in the pipe. In high-pressure areas, air chambers, which are pipes filled with air, are installed at the fixtures connected to the water line. They provide a cushion of air that lets the pres sure build up more gently. Pressure buildup is a serious problem that, if gone uncorrected, will result in broken or leaking pipes. It may be possible for a plumber to install one or two large air chambers in the system or a variety of other mechanical devices designed to correct the trouble.

The sound of running water is caused by undersized pipes and pipes that run in walls that aren't sound-insulated. Wrapping the pipe with a noise-insulation material may help. If the noise is very objectionable, the pipe may have to be replaced with a larger one.


Few people will argue about the substantial advantage of being connected to a municipal sewer system by a single outlet or separately into the sanitary and storm-water disposal system. The MPS requires that, when available, the municipal sewer system must be used. With the increasing awareness of the damaging effects of pollution on the environment, the rapid improvement and expansion of these systems can be expected in the near future. Health experts estimate that 50 % of the septic systems now in use aren't working properly. Still, it's estimated that almost 50 million people in 15 million homes, especially in the suburbs and rural areas, depend on septic tanks for their waste disposal and that 25 % of the new houses being constructed aren't connected to municipal systems.

A typical septic system, shown in Figure 8.14, consists of a large concrete tank with a capacity of 900 gallons (about 8 by 4 by 4 feet) buried in the ground. One end accepts the waste material from the house drain line. Once inside the tank, the waste tends to separate into three parts. The solid waste materials (only about 1 % of the total volume) sink to the bottom. The grease (also less than 1 % of the total volume) rises to the top. The rest is liquid. Bacteria in the tank decompose the solid wastes and grease and a relatively clear liquid flows from the opposite end through the drain line either into a distribution box that directs the liquid into a network of buried perforated pipes called a leaching field or into a seepage pit. From there, the liquid runs off into the ground to be absorbed.

Fig 8-14: Septic Tank and Absorption-Field System

The required capacity of the tank depends on the size of the house and the usage. The size of the leaching field depends on the soil’s capacity to absorb water. The rate at which the soil will absorb water can be measured by making a percolation test. A hole at least 12 inches deep is dug in the ground and filled with water. Each hour the depth of the water is measured. Anything less than an inch decrease in depth each 30 minutes is substandard. This test should be carried out during the wettest season of the year and preferably by an expert. Usually, the local health department will conduct the test at no cost or for a nominal charge. Also, it's likely that the local health authorities will have previous knowledge of the individual system.

Septic tanks must be checked frequently to make sure that they aren't clogged and that the bacterial action is working properly. Chemicals must be used with care for they can kill the bacteria. Often, the tank must be pumped out and the cycle started anew.

A cesspool is similar to a septic tank except that instead of a tank there is a covered cistern of stone, brick or concrete. The liquid seeps out through the walls directly into the ground rather than into a leaching field or seepage pit. It is important to learn about a house’s particular system, including the location of the clean-out main, which often is buried in an unmarked spot, so that inspections and repairs can be made as required. A properly working system should produce no odor, which is one of the first signs of trouble.

To gain information on septic systems, a person should find out how often the system has to be pumped out. In many towns, the local health officer is very knowledgeable about many systems in his or her jurisdiction and of problems in general in a particular neighborhood. Learning the location of the clean-out main from the current owner saves a lot of digging and searching if the main is buried.

Septic-system problems sometimes may be corrected by simply pumping out the tank. Sometimes new leaching fields are required. Unfortunately, there are situations when the soil-absorption rate is poor or the water table is close to the surface and little can be done to make the system function properly.



Evidence in prehistoric caves shows that man was using inside lighting before the beginning of recorded history. Homer’s Iliad, written sometime before 700 B.C., tells of torches used for light. Metal torch holders are found in medieval houses and inside castles, indicating that torches were a popular light source. Abraham Lincoln, according to legend, read by the light of the hearth, which had been a light source long before his time.

Braziers filled with pitch and chips of resinous wood made a surprisingly bright, but smoky light. The candle probably was invented by the Etruscans and passed on to the Romans many hundred years before Christ. Candles still are very popular today for decorative, romantic, religious and emergency lighting.

Another basic light source was the liquid-filled lamp, such as rudimentary stone dishes burning melted fat; an advanced form was the whale oil lamp widely used in this country. The discovery of oil led to the kerosene lamp and the gas light fixture.

Thomas Edison created the first commercially practical light bulb in 1879. In addition, he developed a complete distribution system for electric light and power that included everything from the generator to the light socket and bulb, junction boxes, fuses, underground conductors and the other devices needed to make modern electric living a reality. In 1882, he built the world’s first central electric power plant.

It is possible to judge the total impact of Edison’s genius on modern life by comparing two Sears, Roebuck and Company catalogs. The 1898 Sears catalog had more than 700 pages and claimed to have “about every thing the customer uses.” It had books on electricity, an electric motor for no stated purpose and some telephones. It contained no electric light fixtures or bulbs, no toasters, a waffle iron that sat on top of the stove burner, no radios or TV sets.

By 1976 the Sears catalog contained about 1,600 pages and modestly stressed “guaranteed satisfaction” rather than completeness, although it certainly was a very complete representation of things then in use. It had books on electricity, an assortment of electric motors, telephones, numerous kinds of light bulbs, electric radios and televisions, plus ten pages of light fixtures. For the kitchen alone, there were electric stoves, refrigerators, freezers, ventilation fans, mixers, blenders, can openers, choppers, coffeepots, frying pans, waffle irons, oven broilers, hot plates, juicers, steam irons, ice-cream makers, knives and garbage disposals. Apparently, Americans have become addicted to electric appliances and have no intention of being cured.

Principles of Electricity

Electricity is a form of energy. A few simple universal and unchangeable physical laws apply to it. One of these laws, stated in very simple terms, is that energy can be changed from one form to another. This is what Thomas Edison did when he built the first commercial generator plant on Pearl Street in New York City in 1882. In this plant, energy stored by nature thousands of years ago in coal was changed into electricity. Today, that's what is being done in generating plants all over the country by the utility companies. These plants change energy stored in coal, oil, water and atoms into electricity.

Another law, again simply stated, is that energy may be converted into heat or light by running it through some resistance. This is what hap pens in a stove, light bulb, resistance heating unit and any other electric appliance that produces light or heat.

Electricity will travel from its source to the ground at the speed of light (which is instantaneous for all practical purposes) unless stopped by resistance. A substance that has high resistance is called an insulator (glass, wood, rubber and porcelain are a few common items that have high resistance). A substance that has low resistance is called a conductor (copper, aluminum, iron, steel and many other metals have low resistance).

The way to get electricity to a desired location is to provide a path of low-resistance material. This commonly is accomplished with wire made out of low-resistance metal. To keep the electricity from going into the ground before it gets to its intended destination, the wire is surrounded with insulation. Air is an excellent form of insulation. Therefore, bare wiring running through the air really is surrounded with insulation.

The electricity in the wire flowing from its source to the lights and appliances in the house can be compared to water flowing through the pipes from the well or water company. The rate of flow of water is measured in terms of gallons per second. The rate of flow of electricity is measured by amperes (coulombs per second).

The pressure in the water main and pipe is measured by pounds per square inch (p s i) The pressure forcing the electricity through the wire is volts. The water company may have very high pressure in the street main and reduce it to below 80 psi. with a special valve for home use. The electric company may have high voltage in the street lines and reduce it with transformers (devices for changing the voltage of electricity) to 110 to 120 volts or 220 to 240 volts, the two standard pressures used for house lighting and appliances. The actual amount of water used may be measured in terms of gallons. The amount of electricity used may be measured in terms of watt-hours.

When a bulb has 60 watts stamped on its end, this means that it will consume 60 watts of power for each hour it's lit A kilowatt hour (kwh) is 1,000 watt hours E.g., an electric light bulb that's rated 100 watts will use 1 kwh of power for every ten hours it's lit (100 watts x 10 hours). If a kwh costs 3 cents, it would cost 3 cents to leave that light on overnight.

A great deal of electricity is needed to make heat A typical range top may take 5 000 watts To keep it running for just one hour will use 5 kwh (5,000 watts x 1 hour). At the same 3-cent rate, it would cost 15 cents to cook dinner. Some typical watt ratings are as follows: light bulbs, 25 to 300 watts; refrigerator, 300 to 400 watts; garbage disposal, 350 to 500 watts; television set, 300 to 500 watts; toaster, 1,000 to 1,500 watts; washer-dryer, 4,000 to 5,000 watts; water heater, 3,000 to 5,000 watts; range top, 3,000 to 12,000 watts; and air-conditioners, 3,000 to 12,000 watts.

Electric Service Entrance

Figure 8.15 shows how electric service enters the home. The home wiring system starts with the service entrance that brings the power from the street through an electric meter to a distribution panel. The service entrance may be designed to bring 30, 60, 100, 150, 200, 300 or 400 amperes of electricity into the house.

Fig 8.15 Electric Service Entrance.

Here is the usual relationship between ampere service, number of circuit breakers and maximum number of watts:

Size of Service

30 amperes

60 amperes

100 amperes

150 or more amperes

No. of Branch Circuits (fuses or circuit breakers)


6 to 8

12 to 16

20 or more

Max. No. of Watts




30,000 or more

A 30-ampere service will provide electricity for a total usage at one time of 6,900 watts. This amount of service still is found in many older one-family homes. The panel box (usually black) most often has four fuses in it. It will provide enough electricity for lighting and very limited appliance use. This amount of service is below FHA standards, however, is obsolete and should be replaced.

A 60-ampere service was the standard for many years for small to medium-sized houses. It still is acceptable, according the MPS, when it can be demonstrated that the demand will be no more than 13,800 watts. A builder installing a 60-ampere service today, however, probably is trying to save money and should be judged accordingly. Many homeowners with 60-ampere services are converting to larger services. A 60-ampere service panel box usually has only 6 to 8 fuses or circuit breakers.

A 100-ampere service is the standard today for most small and medium-sized houses without electric heat or central air-conditioning. It provides 23,000 watts of power. A typical panel box will have 12 to 16 fuses or circuit breakers. There also may be some small separate distribution boxes for the major appliances. A house with less than a 100-ampere service is or soon will be obsolete.

In larger houses and where electric heat, central air-conditioning or a large number of appliances are used, 150-ampere to 400-ampere services are needed. The 150-ampere service is being used for houses without electric heat where pennies aren't being pinched by the builder.

Most homes today are served by a three-wire, 220-volt to 240-volt ser vice. The electricity is brought from the transformer at the street into the house through three wires. Two wires each carry 110 to 120 volts and the third is a ground wire. The wires are strung through the air overhead and connected to a service head, then run through a piece of conduit pipe down the wall to the electric meter (which may be inside or outside the house) into a distribution panel box. An alternate method is to bring the wires in from the street through underground conduit pipe. The use of underground wires is increasing as public resistance to the unsightly over head wires increases.

Figure 8.16 shows the components of the electrical system within the house.

fig 8.16 electrical system components: types of wire; types of fuses

Distribution Panel and Protective Devices

The distribution box first of all must provide a switch that will cut off all electric service to the house when the switch is manually pulled. This is needed in the event of an emergency, when work is to be done on the system or for any other reason when the system may be required to be disconnected. It also must contain either a fuse or a circuit breaker that will disconnect the entire system automatically if the system is overloaded. This occurs when the system is called on to provide more watts than it's capable of providing or if a short circuit takes place because of a break in a wire, a faulty appliance or two wires touching each other.

Fuses and circuit breakers are the two types of devices used to cut off the electricity automatically. A fuse is nothing more than a piece of wire that will melt when more than the prescribed amount of electricity flows through it, thus making a gap in the wire system across which the electricity can't flow. The type of fuse used to protect the entire service usually is cartridge-shaped. The fuse holder should be designed so that it will not hold fuses that are too large for the size of service being protected.

Circuit breakers are special types of automatic switches that will turn themselves off when excess electricity passes through them. They must be turned back on manually and will again turn themselves off if the problem that originally tripped them off has not been corrected. Circuit breakers are designed to wait a moment before they shut the electricity off because of an overload. This is helpful because electric motors draw a large amount of electricity for a brief moment when they start. This over load is harmless if it lasts just the normal short time.

Another advantage of a circuit breaker is that, unlike a fuse that must be replaced when used only once, a circuit breaker only needs to be turned back on to restore the electric service once the problem has been corrected. The only disadvantage of circuit breakers is that they are more expensive than fuses, which accounts for the lack of their widespread use.

The distribution box also divides the incoming electric service into separate branch circuits that lead to the various areas throughout the house. Special branch circuits should be provided for those appliances that use a large amount of electricity such as heaters, air conditioners (some small room air conditioners don't require a separate circuit), ranges and ovens, dishwashers, washing machines and dryers or any other high-use electric appliance.

Each individual circuit also must be protected by a fuse or a circuit breaker. If an overload or short circuit occurs on the circuit, it automatically will shut off without tripping the main fuse or circuit breaker and shutting off the whole house service.

The type of fuse used to protect an individual circuit is different from the cartridge types used to protect the whole service. Here a screw-in fuse is used. Its size may be 15, 20 or 30 amperes, depending on the capacity of the circuit being protected. A special type of fuse known as type S now is required by the National Electric Code (NEC) and the MPS. It has the same momentary delay feature as a circuit breaker. It also requires a special socket that holds only the correct size fuses. Once these sockets are installed in the distribution panel, they can't be removed except with a special tool.

Circuits and Wiring

In the panel box, the electric power is divided into separate branches known as circuits. Each circuit will serve a separate area of the house or an individual appliance. General circuits run to each area of the house. Connected to them are the permanently installed lighting fixtures and receptacle outlets, into which are plugged lamps and appliances. These general circuits are wired with two No. 12 or larger wires and are protected with a 15-ampere fuse or circuit breaker. They provide 1,800 watts of 110-volt to 120-volt power. The NEC and the MPS require 3 watts of power per square foot of floor space for general circuits. A better standard is 5 watts per square foot. Therefore, each general circuit should serve 360 to 500 square feet of floor area. A 1,500-square-foot house could meet the minimum standards with three general circuits but should have five for convenience and expansion.

Special circuits for small appliances are wired with No. 12 or larger wire and are protected with 20-ampere fuses. They provide 2,400 watts of 110-volt to 120-volt power and can't be used for large appliances. The MPS requires at least two special circuits in each house.

Large appliances such as clothes dryers, water heaters, ranges, dish washers, freezers and large window air conditioners require large amounts of watts and often 220 to 240 volts and special three-wire circuits using wire from No. 12 to No. 6 size (the lower the number the larger the wire). These circuits are protected with 30-ampere to 60-ampere fuses or circuit breakers.

If the size of the wire used in a circuit is too small, the lights and appliances don't work at peak efficiency. The bulbs shine dimmer than they should and the appliances don't work as well or get as hot as they are designed to do. In this case, the amount of electricity comes through the electric meter and is paid for even though the electricity isn't providing maximum performance. This is because the undersized wire itself is creating extra resistance and turning the electricity into heat.

The old system of wiring a house was to run two insulated wires parallel to each other from the panel box to the outlets and fixtures. A separate pair of wires was run for each circuit. The wires were run a few inches apart and attached to the house with white porcelain insulators called knobs. When the wire passed through a wall or joist, it went through white porcelain tubes, hence the name, knob-and-tube wiring. This sys tem is obsolete and often must be replaced, which can be a major expense.

Today, nonmetallic cable is the next cheapest system available. Each wire, in addition to its own insulation, is wrapped with a paper tape and then encased in a heavy fabric and treated so that it's water-resistant and fire-resistant. A similar cable has a thermoplastic insulation and jacket. The cables are attached to the joists and studs with staples. They must be protected from damage and normally shouldn't be used outside or underground unless they are plastic-coated. Both of these cables are prohibited in many major cities.

Armored cable (or B.X. cable) consists of insulated wires wrapped in heavy paper and encased in a flexible, galvanized-steel covering wound in a spiral fashion. This system has wider approval but not universal acceptance even though it's less susceptible to physical damage. Surface race- ways made of metal or plastic sometimes are used in houses, mostly for repairs and in solid-core walls and partitions.

Flexible steel conduit is constructed similarly to B.X. cable except that it's installed without the wire. Wires are drawn through the conduit after installation.

Rigid steel pipe, which looks like water pipe, still is the most preferred and expensive method and meets the most rigid codes. Like the flexible conduit, the wires are pulled through after it's installed. The larger the size of the conduit, the more wires and larger wires can be pulled through it. Most outdoor installations are rigid conduit, although a vinyl insulated wire has been developed that can be buried in the ground.

Telephones and doorbells use low-voltage wiring that does not present a safety hazard and therefore can be run loose throughout the walls and along the joists. Many houses now are prewired for telephones, which eliminates the necessity of the telephone company cutting into the walls and floors after the house is complete.

Intercommunication and music systems also are becoming very popular. These systems also use low-voltage, hazard-free wiring. Music at will through out the house, answering the door without opening it and talking from room to room without screaming are all possible with this equipment.

The rise in crime has increased the number of houses that are wired with burglar-alarm systems. Some houses also have fire-warning systems. and for the rich and the nostalgic, there is the button under the dining room table that, when stepped on, summons the maid from the kitchen, and there is a more complicated set of buttons throughout the house that summons the butler from the pantry.

Inadequate Wiring

The problem of inadequate wiring starts with inadequate voltage and amperage coming into the house. A minimum 220 to 240 volts and 100 amperes should be supplied and more if the house is large, has many major electric appliances (especially ranges and clothes dryers) or has electric heat and air-conditioning.

Lack of sufficient branch circuits to the various appliances and to rooms of the house can be corrected by installing a bigger distribution panel and additional wiring. Using fuses that have higher ratings than are called for is a sign that the wiring is under the needed capacity. Insufficient wall outlets in rooms leads to using dangerous extension cords and monkey plugs. The lack of outside outlets is an inconvenience.

Knob-and-tube wiring must be viewed very suspiciously. It often is old and its insulation has a tendency to crack with age, leaving exposed wires, which are very dangerous.


The duplex receptacle was, until 1960, the most common type of house hold outlet in use. It accepts a two-prong plug, the type most often found on lamps and small appliances. In 1960, the NEC and the MPS required that all receptacles be of the grounding type, designed to also accept a three-prong plug. Many small appliances are wired with a third ground wire that's attached to the frame or metal housing of the appliance. The third slot in a grounded outlet is connected to a water pipe or other grounding metal. Grounding of an appliance using a three-prong plug and receptacle reduces its shock hazard.

Special waterproof receptacles with caps are available for outside use, clock outlets, TV outlets, locking outlets and a variety of other special- purpose outlets. The receptacle for a 220-volt to 240-volt line is designed to accept only special plugs. A standard two-prong or three-prong plug can't be plugged into it. It also is designed to accept only plugs for appliances using only the exact number of amperes that it will supply.

Outlets should be located conveniently throughout the house (see Figure 8.17). The MPS requires that three-prong duplex grounding out lets should be installed in all habitable rooms so that no point along the floor line is more than 6 feet from an outlet. It also requires that an additional outlet between all doors and between doors and a fireplace should be supplied (unless the wall is too small for a piece of furniture); that in rooms without permanent light fixtures, at least three outlets should be provided regardless of the room size; that two outlets should be installed in the kitchen over the counters; and that an outlet should be installed next to the mirror in the bathroom.

Fig 8.17 Minimum FHA-MPS Convenience Outlets: Notice that no point on usable wall space is further than six feet from an outlet.


Wall switches are used to control permanently installed light fixtures and also may be used to control wall outlets. Rooms without permanent light fixtures are becoming very common as ceiling fixtures in some rooms continue to go out of style and lamps gain in popularity. It would be in convenient, however, to have to walk into a dark room to turn on a lamp. A wall switch near the door that controls the wall outlet into which the lamp is plugged eliminates this problem. It also is convenient to control fans, garbage disposals and some other small appliances by a wall switch rather than by the switch on the appliance itself.

The simplest and most common switch is a two-way snap switch that has two copper contact points inside. When the switch is up in the “on” position, a spring snaps the copper contact points together and lets the electricity pass to the fixture or outlet. When the switch is flipped to the “off” position, the spring pulls apart the copper contacts and the electricity is turned off.

Three-way switches are used to control a fixture or outlet from two different places. With this wiring and switching arrangement, the fixture or outlet is turned from “off” to “on” or “on” to “off” when the position of either switch is changed; therefore, the up position isn't necessarily the “on” position or the down position the “off” position. This arrangement is very useful for a stair light, so that it can be controlled from the top or the bottom of the stairs. Other good places are in rooms with two doors, for garage lights, outside lights and bedroom lights (a switch at the door and another at bedside).

Two-way and three-way switches also are made with silver-plated contacts. Because silver is an excellent conductor, less pressure is required at the contact points and the switch is much quieter. A completely silent- type switch uses mercury in a tube to open and close the circuit. The only disadvantage of silver contact or mercury switches is the higher cost. They often are a sign that someone was willing to pay for quality.

Some other, more expensive switches are those with lighted handles (some glow all the time and others only when the switch is in the “off” position). There also are switches that turn on and off when a door is opened or closed (often used in closets), key-controlled switches, pull- chain switches, outside weatherproof switches, touch switches, time-delay switches and a variety of other specialized switches.

Some houses are controlled by a low-voltage switching system. In stead of the switch directly opening and closing the circuit, it controls a. relay that, in turn, operates the switch. The advantage of this system is that control panels, located throughout the house, can control many lights and outlets from one place. These control panels often are located at the main entrance or in the master bedroom.

Dimmer switches are used to vary the intensity of the light while leaving the same number of fixtures on rather than by the old way of just turning some fixtures off. This more-sophisticated method allows for much better light distribution and better decorative effects.

A good indication of an adequate switching arrangement is the ability to walk anywhere in the house and turn on a path of light and then turn off the lights without having to retrace steps or walk in the dark. This includes getting in and out of bed and entering and leaving the house by both entrances and through the garage. Some houses have additional switches to control light at remote locations, such as a switch in the master bedroom controlling the outside lights.

Artificial Lighting

Studies continue to show that only a small percentage of houses have adequate lighting or the wiring needed to add the necessary Lamps and fixtures to correct this deficiency. The public, however, is becoming more and more aware of what adequate lighting is and all of its advantages. As more people demand this lighting, houses without it will become obsolete.

Most home lighting is provided either by incandescent bulbs or by fluorescent tubes. Each has very different light characteristics.

The amount of light a bulb emits is measured in lumens. In general, the more watts of power a bulb uses, the more lumens or light it gives out. To determine how much light a lumen is, one should consider that a candle gives off between 10 and 15 lumens. A frosted 100-watt bulb emits about 1,600 lumens (16 lumens per watt) when it's new and getting enough electricity. One hundred watts of fluorescent tubing will emit about 7,000 lumens (70 lumens per watt). More than four times as much light from fluorescent tubes is available than from incandescent bulbs using the same amount of electricity.

The amount of lumens required varies according to the activities carried on in each room. Following is a guide to the amount of lumens needed in each room according to a recent study: kitchen, 80 lumens per square foot; bathroom, 50 lumens; bedrooms, 35 lumens; living room, 40 lumens; family room, 50 lumens; dining room, 40 lumens; and hallways, 30 lumens.

It is easy to figure out the amount of bulb watts that's required to adequately light a room. E.g., a bedroom that's 10 by 12 feet has 120 square feet that, when multiplied by 35 lumens per square foot, indicates a need for 4,200 lumens of light. When divided by 16 lumens a watt, the answer indicates that about 260 watts of bulbs are needed. There is a difference in the number of lumens given per watt depending on the size of the bulb but not enough to make a significant difference. The same room can be lit adequately with about 60 watts of fluorescent tubing, as indicated by dividing the needed 4,200 lumens by 70 lumens per watt produced by the fluorescent tubing. Apparently, a fluorescent light gives a good deal more light for the same amount of watts used. Fluorescent fixtures, however, are much more complex and expensive.

The trend is to build more lighting into the house in the form of recessed fixtures using fluorescent tubes, spotlights, floodlights and other specialized fixtures that each produce a distinct pattern of light best suited to a specific area.

Bathrooms require special lighting. When the mirror is used for shaving or makeup application, both sides of the face and the area under the chin should be well-lit without shadows. The light should be bright but not so bright that pupils contract or squint from the glare. The color balance should make skin look lifelike.

There also should be additional general lighting in the bathroom and in the shower stall. Pull chains and switches located in areas where they can be reached from the tub should be avoided because they present a shock hazard.

It is beyond the scope of this guide to go into greater detail about house lighting. Suffice it to say that the entire interior appearance of the house is affected by the use of artificial light and that adequate light is important to a family’s health and happiness.


A popular home-automation system marketed nationally has a central keypad console that controls the entire system. The system also can be controlled remotely by calling it on the telephone.

It includes a complete home-security system that has infrared sound, smoke, fire, heat and noise detectors. It automatically notifies a central station or dials the police and /or fire department when a problem is detected.

It turns lights and appliances on and off at preprogrammed times. Besides regulating the traditional appliances, it can be programmed to control the pool pump, sink, bathtub, etc. It takes complete control of the heat and cooling systems.

When an occupant is away, he or she can call in and check on the home’s status. If anything has happened, it will be reported.

Many additional features can be installed independently or made part of the central electronic control and monitoring system.

Electronic water valves on the bathtub and shower automatically control the water temperature. Installed on sinks, they sense the presence of hands and supply water at preset temperatures whenever activated. Electronic water valves turn lawn-watering systems on and off at pre-selected times.

A variety of special alarms are available that detect any use of the swimming pool, motion inside or outside the house, floodwater in the basement, unusual rises or drops in home temperature, etc. Inexpensive TV cameras can be used to monitor doors, walks, pools and children’s rooms. Intercom systems are voice-activated, transmitting music through out the house, and are connected to the telephone system.

What these electronic controls will do seems limitless. They even open the cat door only for the cat who wears a special electronic collar that activates the door.

The cost of these complex home-automation systems starts at under $2,000. With all the available features, they can cost in the tens of thousands of dollars.

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