|Home | Insulation | Conserving Energy
Heating | Books | Links
We can save money and live a more comfortable life by being fuel smart. Simple changes can save enough energy to make a big difference in your bottom line. This guide will provide information and guidance on some practical and affordable things you can do to your home and in your daily life to save energy.
First, a quick lesson on how your home loses heat.
— Conduction: Hold a glass filled with hot water in your
hand. The outer surface of the glass feels warm. Heat is transferred from
the water to your hand through the glass by conduction.
A material that slows the flow of heat can be used as insulation. Most insulation materials work in basically the same way. They trap air in tiny pockets and prevent air cur rents from quickly taking the heat away.
The ability of a material to stop heat flow and act as insulation is indicated by its “R-factor.” The higher the R-factor, the better the insulation. When buying insulation, always look for the highest R-factor. You must also consider other factors: cost, ease of installation, durability flammability, and water resistance.
— Convection: Hold a stick of incense next to a cold window. Which way does the smoke go? Down. Hold it next to a warm radiator. The smoke rises. The smoke is riding on cur rents of air. Because cold air falls, near a chilly window air currents go down. Conversely, near a radiator air rises. Air currents carry heat from one place to another.
On windy days, a thin film of air surrounding our bodies is swept away by the wind. We lose heat. Our bodies heat another layer of air. Again, it is swept away. This is another example of convection.
Homes lose heat through convection. Heated air constantly rises inside your home and is swept away through holes or cracks. Cold air enters, especially near the floor. Convection in the home is often felt as a draft.
— Radiation: Do you feel cold when you stand next to a large picture window on a cold winter day? Does your front feel warm and your back feel cold when you stand facing a hot woodstove? In each case, radiation is at work. Warm surfaces radiate or lose their heat to cold surfaces. You are radiating your heat to that cold window. The woodstove radiates its heat to the room. Radiators work through radiation and convection. The surface area radiates heat, and air cur rents carry it into the room.
We will be using these concepts as we guide you through ways to save energy. It is helpful to know how heat energy is transferred when you’re trying to reduce heat loss.
Note: The Sections on home weatherization cover mostly heating. If you live in a region where it is hot in the winter and even hotter in the summer, these same practices will help you save on your cooling bill. Sections later in this guide will focus on cooling.
Your Home Is a System
Over the past twenty years, we have learned that the house is a system. If you do something to one area, you will probably affect another area. That’s why you need to consider humidity, moisture, and air quality when you are contemplating energy improvements.
I will point out how these systems interact in the discussion of each topic. For example, condensation relates to the degree of insulation. Warm air can hold a lot of moisture. When the air cools down, it can hold less moisture. On hot, humid summer days, have you ever noticed water dripping down the outside of a cold glass of lemonade? As the warm air comes into con tact with the cold glass, the water vapor in the air loses temperature and is converted to water. The moisture is known as condensation.
In your home, warm air is conducted through glass, walls, floors, and ceilings to the outdoors. When you weatherize your home you want to make sure that the warm air, as it cools, does not condense in your walls, on your windows, or inside the insulation. One way to prevent condensation is by installing a vapor barrier toward the heated space. The vapor barrier prevents the moisture from leaving the heated space.
The key to success is understanding the way all the little things you do around the house add up to the big picture. The good news is that you can make a difference. If you apply even a fraction of the hints and tips in this guide to your own home, you will see immediate cost savings in your utility bills. Perhaps even more important, you will be helping to conserve the world’s energy resources.
Next: Get Ready for Winter!