A do-it-yourself energy audit
Q. I don’t have a huge budget to work with, but I would like to make my house more energy efficient. Instead of spending some of it on a professional energy audit, how can I do an energy audit myself?
A. Even if your house is already reasonably energy efficient, there likely are quite a few inexpensive improvements that can yield a good return. Other than major equipment and material improvements, you should be able to do many of them yourself for only the material costs.
It is important to get an idea of how generally efficient your house is. One way to do this is to total all the energy used by your house over an entire year or more years if possible. This total amount of energy will be adjusted for your climate and size of your house. Obviously a large house in northern Michigan will use more energy than a small one in San Diego.
The total energy consumed by your house should measured in Btu (British thermal units). One Btu is roughly the amount of heat given off by burning a wooden kitchen match. The majority of the total can be determined from your utility bills, but don’t forget wood used in the fireplace or other energy sources such as propane and oil.
Find your utility bills for a one-year period, preferably a calendar year for simplicity. Use these conversion factors to get the Btu equivalents: 1 kilowatt-hour of electricity — 3,414 Btu; 1 cubic foot of natural gas — 1,025 Btu; 1 gallon of propane — 91,000 Btu; 1 gallon of oil — 138,700 Btu; and 1 cord of wood — 19 million Btu.
Contact your local weather station office to find the number of heating and cooling degree days for the year. Don’t just use an average for your area because it can vary significantly from year to year. This number represents the severity of the weather. Divide the total number of Btu by this number.
Divide this result by the total square footage of your house. A number less than 10 indicates a very efficient house and it may be difficult to find many cost-effective improvements. A range from 10 to 20 is more common. A number above 20 means the house is inefficient and it should be easy to find inexpensive efficiency improvements with a good payback.
The three primary inefficiencies are from air leakage, inadequate insulation and inefficient old heating and cooling units. On a windy day, move a lighted stick of incense around the edges of the windows and doors. Observe the trail of the smoke to locate leaky spots. This also works for finding leaks at joints in the duct system.
Putting your hand on the wall to feel the temperature can identify areas of inadequate insulation. Low-cost, hand-held devices are also available to find hot and cold spots on the wall. Tape a thermometer on the wall by the furnace thermostat to check the accuracy of the thermostat. You may be keeping your house warmer or colder than you realize, which significantly increases your overall energy usage.
Q. Last summer, I noticed water on the floor around my furnace when the central air conditioner was running. I assume it is from the evaporator coils. What can I do to eliminate the water leakage?
A. When the air conditioner is running, the evaporator coils get very cold. They sweat similar to a cold soft drink can on a hot summer day. This water is supposed to drip into a pan and drain out through a hose.
Hopefully it is just a clogged hose that is causing the drip pan to overflow. Clean out the drain tube. The other reason is a rusted out drip pan. This will require a professional service call to have it replaced.
Ÿ Write to James Dulley at 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit dulley.com.