Commonly called an Energy Audit – The process of diagnosing and recommending improvements to reduce a home’s energy consumption. It is not a new idea, but the reasons to get your home tested are more pressing as concerns about energy costs, comfort, personal health and the environment loom larger than ever. There are many “Energy Audit” offers these days, even some of the “big box stores” offer them. Most of these are visual inspections with scripted recommendations. The better solution is a Comprehensive Home Energy Audit performed by trained, experienced experts using sophisticated testing equipment. T he primary tool used is an infiltrometer, sometimes referred to as a blower door test.
You may have seen these on TV, on This Old House or HGTV or i n magazines like Popular Science and National Geographic. Using the infiltrometer during H.E.E.T, we depressurize the house. Once the predetermined pressure is attained, we record the amount of airflow required to reach that pressure. This is how we quantify the home’s leakage. The more airflow it takes to attain the predetermined pressure, the leakier the house.
So,now we know how tight the house is,now what? This is where the standard,generic or scripted responses,like you need new windows or more insulation, fall short. Because we measure and can physically see (using a smoke puffer) if there actually is leakage around windows.We can also determine if there is missing or inadequate insulation in walls or attics using an infrared thermal imaging camera. While the infiltrometer is still running, we use the smoke puffer and the infrared thermal imaging camera and a special tool, called a balometer, that measures airflow in cfm (cubic feet per minute) to measure for duct leakage. According to a Department of Energy report, duct repairs may be the most important energy improvement you can make. Typical duct systems lose 25-40% of the heating and cooling energy put out by the furnace, air conditioner or heat pump. Homes with ducts in protected areas, like basements, may lose somewhat less than this while other types of duct systems, like attic or kneewall systems, often lose more.
Most duct systems are original to the home. Some older houses have duct systems that date back to coal burners and gravity furnaces. Even if they are newer, they were probably engineered and installed by the lowest bidder the builder could find. Duct leakage is a primary concern. Ducts experience much higher pressure than house leaks. One square inch of duct leakage to the outside has approximately the same impact as 30 square inches of leakage around windows and doors.