Tim Gould
Many homeowners want to conserve the energy used to heat and cool their homes, but they are not sure where to start.
One of the best first steps is an energy audit. But not all audits are created equal. An effective energy audit will give homeowners accurate and useful information that they can immediately use to make energy-saving home improvements. Homeowners can do research over the Internet to make sure they are contracting for a thorough energy audit or ask questions of an auditor based on the information given below.
In order to conduct an effective energy audit, the right diagnostic tools are necessary. The first tool is a blower door. The blower door is basically a big fan; it has a digital gauge that measures the rate of air flow leaving a house at an established inside versus outside pressure difference.
The blower door is temporarily installed and fitted, using an adjustable frame, to the home's front door. The reported rate of flow through the fan indicates how leaky a house is, and while the fan is running, it allows the auditor and homeowner to walk through the premises and find the areas of air leakage. This depressurization test is a valuable diagnostic tool and most always reveals air leaks in previously unsuspected areas that can be caulked and sealed to save energy.
A second diagnostic tool that is very helpful is an infrared camera. The camera can be used to see conductive heat loss, as well as where insulation is inadequate. When the infrared camera is used during the house depressurization test, convective heat loss is visible.
Problem areas come alive in a colorful display (with a range of colors showing temperature variances). Accurate infrared thermography shows where outdoor air is traveling through ceilings, walls and floors so that they can be air-sealed and better insulated.
The third component of an effective energy audit is a knowledgeable auditor. The auditor should have a good understanding of energy principles, heat transfer and home construction so that he or she can identify the problems and not miss opportunities for significant energy savings. An auditor should know how to interpret the results from the blower door with actual energy-consumption information gathered from the house and the homeowner.
This analysis is crucial to providing accurate comparative data demonstrating whether it is cost-effective to undertake energy conservation measures, as well as which measures are most cost-effective. Lastly, a well-trained auditor should be able to show how much heat loss in dollars is attributable to air leaks, be able to interpret infrared images and know how to create an understandable report that is useful to homeowners in prioritizing their home's energy conservation measures.
As a reminder to National Grid gas customers, the 75 percent rebate up to $2,000 on audit and energy efficiency improvements expires March 31. Audits and improvements must be done by a pre-approved contractor.
Tim Gould is director of Energy Egghead, an Amesbury-based company that can be found at www.energyegghead.com and provides professional energy audit and conservation services.
