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Conducting Energy Audits

A great follow-up step to using a home energy calculator is to conduct a home energy audit. The goal of an audit is to develop a specific list of existing problems that may, when corrected, save the homeowner significant amounts of energy expense. Home energy audits identify where energy is being lost from a home. Audits can also determine the efficiency of a home's heating and cooling systems.

Home energy audits identify drafts and leaks around doors and windows or in the ductwork through which conditioned air flows. They can also determine whether a home has adequate insulation in its walls, ceilings, attic, and foundation. Audits can highlight ways to conserve hot water and electricity. There are two ways of obtaining a home energy audit— homeowners can do it themselves or hire a professional home energy auditor.

Do-It-Yourself Energy Audit

With a little time and attention, the homeowner can perform an effective energy audit. A home energy audit covers several key areas: air leaks in the building envelope, adequacy of insulation, and efficiency of the heating and cooling systems.

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  Air Leaks:

  The first step is to identify and note where air is leaking and drafts are entering the home. Common air-leak locations include window frames and doors, ceiling hatches that lead into an attic, fireplace dampers, wall or window-mounted air conditioners, baseboards, and electrical switch plates and outlets. The potential energy savings from fixing these types of home air leaks ranges from a 5 percent to a 30 percent reduction in energy bills.

   

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  Insulation:

  The next item to examine is insulation. Many homes, depending on age, may have inadequate amounts of insulation. Heat loss through a home's ceiling and walls could be quite large if the insulation levels are less than the recommended minimum. In homes with attic hatches, the hatch should be weather-stripped and insulated at least as heavily as the attic. It should also close tightly.

   

  The attic should have a vapor barrier under the attic insulation. The vapor barrier might be tarpaper, kraft paper attached to fiberglass bats, or a plastic sheet. If there is no vapor barrier, the interior ceilings can be painted 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.

  Checking insulation levels in exterior walls is more difficult. Checking electrical outlet openings can provide a sense of how much insulation is in the wall cavity. Another approach is to make a small hole in a closet, behind a couch, or in some other unobtrusive place to check the filling of the wall cavity. Ideally, the wall cavity should be totally filled with some form of insulation material. Unfortunately, this method does not reveal whether the entire wall is insulated. To determine this, only a thermographic image can provide the needed perspective.

  Homes with unheated basements should have insulation under the living area flooring. In most areas of the country, an R-value of 25 is the recommended minimum level of insulation. If the basement is heated, the foundation walls should be insulated to at least R-19. The water heater, hot water pipes, and furnace ducts should all be insulated.

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  Heating and Cooling Systems:

  Heating and cooling equipment should be inspected annually or as recommended by the manufacturer. The filters in forced-air furnaces should be checked and replaced as needed. Generally, the filters should be changed about once every month or two, especially during periods of high usage. A professional should check and clean heating and cooling equipment once a year.

   

  The homeowner could benefit from replacing a heating and cooling system more than 15 years old with one of the newer, energy-efficient units. A new unit would greatly reduce energy consumption, especially if the existing equipment is in poor condition. Dirt streaks, especially near ductwork seams, indicate air leaks and should be sealed with duct mastic. Ducts or pipes that travel through unheated spaces should be insulated with a minimum of R-Value 6 insulation.

• Lighting:

  Quick and easy energy savings can often be found by auditing a home's lighting system. The higher the wattage of a light bulbs, they more energy it uses. A 60- or 75-watt bulb might be fine where a 100-watt (or larger) bulb is being used. Using fluorescent tubes or compact fluorescent lamps (CFLs) can provide significant energy savings especially if they are replacing conventional incandescent bulbs.

Professional Home Energy Audit

A professional energy auditor will provide a detailed and in-depth look at where energy is being wasted within a home. The energy auditor should do a room-by-room examination of the home, as well as a thorough analysis of past utility bills. The outside of the home including number and size of windows and wall area should be examined.

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  Preparing for an Energy Audit:

  Prior to the arrival of the energy auditor, the homeowner should make a list of existing problems such as condensation and uncomfortable or drafty rooms. It is important to have summaries of energy bills covering electricity and natural gas consumption. Utility companies can provide these upon request.

   

  The professional energy auditor will likely use specialized equipment to detect sources of energy loss, such as blower doors, infrared cameras, furnace efficiency meters, and surface thermometers. These tools and technology provide a comprehensive and accurate assessment.

• Selecting an Energy Auditor:

  Several sources help the homeowner locating professional energy auditing services. State or local government energy or weatherization offices may help identify a local company or organization that performs audits. They may also have information on do-it-yourself audits. Electric or gas utilities may conduct residential energy audits or recommend local auditors.