Professional Energy Audit
Professional auditors use a variety of techniques and equipment to determine the energy efficiency of a home. Usually requiring several hours to a full day to conduct, they generally range in price from $250 to $500 depending on the services performed. Any retrofit work would of course cost additional money, but some companies offering energy audits will discount the price of the audit if follow-on work is performed.
A professional energy audit should include a walk-around and a walk-through to identify problems. The auditor should do a room-by-room examination and do a careful examination of past utility bills. Thorough audits often use equipment such as blower doors, which measure the extent and location of air leaks, as well as infrared cameras, which reveal hard-to-detect areas of air leakage and missing insulation.
A blower door is a powerful fan that mounts into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings. These tests determine the home's rate of air infiltration.
Infrared scanning, or thermography, is used to detect hot spots, cold spots and air leakage in building envelopes. Thermographic scans are also commonly used when the blower door is running. The blower door helps exaggerate air leaking through defects in the building shell. Such air leaks appear as black streaks in the infrared camera's viewfinder.
Before the auditor visits your house, make a list of any problems or concerns you want to discuss. Have copies or a summary of the home's energy bills. The auditors use this information to establish what to look for during the audit.