Do-it-yourself home energy audits
Ahome energy audit will show you problems that may, when corrected, save yousignificant amounts of money over time. During the audit, you can pinpoint whereyour house is losing energy. Audits also determine the efficiency of your home'sheating and cooling systems. An audit may also show you ways to conserve hotwater.
You can easily conduct a home energy audit yourself. With a simple, butdiligent, "walk-through," you can spot many problems in any type ofhouse. When auditing your home, keep a checklist of areas you have inspected andproblems found. This will help you prioritize your energy efficiency upgrades.
|Step 1: Locating air leaks|
- First, make a list of obvious air leaks (drafts). The potential energy savings draft reduction may range from 5% to 30% per year, and the home is generally much more comfortable afterwards.
- Check for indoor air leaks such as gaps along the baseboard or edge of the flooring, and at junctures of the walls and ceiling.
- Check to see if air can flow through electrical outlets, switchplates, window frames, baseboards, weather-stripping around doors, fireplace dampers, attic hatches, and wall- or window-mounted air conditioners.
- Look for gaps around pipes and wires, electrical outlets, foundation seals, and mail slots.
- Check to see if the caulking and weather-stripping are applied properly (no gaps or cracks), and are in good condition.
- Inspect windows and doors for air leaks. See if you can rattle them, since movement means possible air leaks. If you can see daylight around door and window frames, then the door or window leaks. You can usually seal these leaks by caulking or weather-stripping them.
- Check the storm windows to see if they fit and are not broken. You may also wish to consider replacing your old windows and doors with newer, high-performance ones. If new factory-made doors or windows are too costly, you can install low-cost plastic sheets over the windows.
If you are having difficulty locating leaks, you may want to conduct a basicbuilding pressurization test. First, close all exterior doors, windows, andfireplace flues.
- Turn off all combustion appliances such as gas burning furnaces and water heaters. (Remember to turn them back on when you are done with the test.)
- Then turn on all exhaust fans (generally located in the kitchen and bathrooms) or use a large window fan to suck the air out of the rooms. This increases infiltration through cracks and leaks, making them easier to detect. You can use incense sticks or your damp hand to locate these leaks. Moving air causes the smoke to waver, and you will feel a draft when it cools your hand.
On the outside of your house, inspect all areas where two different buildingmaterials meet. For example: inspect all exterior corners; where siding andchimneys meet; and areas where the foundation and the bottom of exterior brickor siding meet.
Youshould plug and caulk holes or penetrations for faucets, pipes, electricoutlets, and wiring. Look for cracks and holes in the mortar, foundation, andsiding, and seal them with the appropriate material. Check the exterior caulkingaround doors and windows, and see whether exterior storm doors and primary doorsseal tightly.
A word of caution: When sealing any home, you must always be aware ofthe danger of indoor air pollution and combustion appliance"backdrafts." Backdrafting is when the various combustion appliancesand exhaust fans in the home compete for air. An exhaust fan may pull thecombustion gases back into the living space. This can obviously create a verydangerous and unhealthy situation in the home.
In homes where a fuel is burned (i.e., natural gas, fuel oil, propane, orwood) for heating, be certain the appliance has an adequate air supply.Generally one square inch of vent opening is required for each 1,000 Btu ofappliance input heat. When in doubt, contact your local utility company, energyprofessional, or ventilation contractor.
|Step 2: Inspecting insulation|
Heatloss through the ceiling and walls in your home could be very large if theinsulation levels are less than the recommended minimum. You should check to seeif the level of the attic and wall insulation of your home is at least at theminimum recommended amount.
When your house was built, the insulation recommended at that time wasinstalled. Given today's energy prices, and that future prices probably willbe higher, the level might be inadequate, especially if you have an older home.In 1997, the U.S. Department of Energy updated its recommended insulationR-Values (see Insulation Fact Sheet, below).
First, the attic
- If the attic hatch is located above a conditioned space, check to see if it is at least as heavily insulated as the attic, is weather-stripped, and closes tightly.
- In the attic, determine whether openings for items such as pipes, ductwork, and chimneys are sealed. Any gaps should be sealed with an expanding foam caulk or some other permanent sealant.
- If you have recessed light fixtures, determine if they are IC rated fixtures. It is strongly recommended that only air tight-IC rated fixtures be used. Other types allow large amounts of your heating dollar to escape into the attic. If you do not wish to purchase new IC rated fixtures, be certain to allow a three-inch space around any recessed lights. This will prevent the recessed light from overheating.
- While you are inspecting the attic, check to see if there is a vapor barrier (retarder) under the attic insulation. The vapor barrier might be tar paper, kraft paper attached to fiberglass batts, or a plastic sheet. If there does not appear to be a vapor barrier, you might consider painting the interior ceilings with vapor barrier paint. This reduces the amount of water vapor that can pass through the ceiling. Large amounts of moisture can reduce the effectiveness of insulation and promote structural damage.
- Make sure that the attic vents are not blocked by insulation. You also should seal any electrical boxes in the ceiling with flexible caulk (from the living room side or attic side) and cover the entire attic floor with at least the recommended amount of insulation.
Checking a wall's insulation level is more difficult.
- Select an exterior wall and turn off the circuit breaker or unscrew the fuse for any outlets in the wall.
- Be sure to test the outlets to make certain that they are not "hot." Check it with a lamp or portable radio.
- Remove the cover plate from one of the outlets and gently probe into the wall with a thin, long stick or screwdriver. If you encounter a slight resistance, you have some insulation there.
- You could also make a small hole in a closet, behind a couch, or in some other unobtrusive place to see what, if anything, the wall cavity is filled with. Ideally, the wall cavity should be totally filled with some form of insulation material. Unfortunately, this method cannot tell you if the entire wall is insulated, or if the insulation has settled. Only a thermographic inspection (by a professional auditor) can do this.
On to the basement:
If your basement is unheated, determine whether there is insulation under theliving area flooring. In most areas of the country, R-25 is the recommendedminimum level of insulation. The insulation at the top of the foundation walland first floor perimeter should have an R-Value of 19 or greater. If thebasement is heated, the foundation walls should be insulated to at least R-19.Your water heater, hot water pipes, and furnace ducts should all be insulated.
|Step 3: Inspecting heating/cooling equipment|
Inspect heating and cooling equipment annually, or as recommended by themanufacturer.
- If you have a forced air furnace, check your filters and replace them as needed. Generally they should be changed about once every month or two, especially during periods of high usage.
- Have a professional check and clean your equipment once a year.
- If the unit is more than 15 years old, you should consider replacing it with one of the newer, energy-efficient units. This would go far to reduce your energy consumption, especially if the existing equipment is in poor condition.
- Check your ductwork for dirt streaks, especially near seams. These indicate air leaks, and they should be sealed with a duct mastic.
- Insulate any ducts or pipes that travel through unheated spaces. An insulation R-Value of 6 is the recommended minimum.
|Step 4: Inspecting lighting|
Energyfor lighting accounts for about 10% of your electric bill.
- Examine the wattage size of the light bulbs in your house. You may have 100 watt (or larger) bulbs where 60 or 75 watts would do.
- You should also consider compact fluorescent lamps for areas where lights are on for hours at a time. Your electric utility may offer rebates or other incentives for purchasing energy-efficient lamps.
Information in this story comes from the U.S. Department of Energy EnergyEfficiency and Renewable Energy Network (EREN).
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