A home energy audit is a very important assessment of your home's physical conditions as they relate to its energy performance. A home energy assessment allows you to identify and prioritize the most effective strategies to decrease your energy usage. According to the Department of Energy, you can save 5-30% on energy bills by utilizing the recommendations provided in an energy audit.1
Professional energy audits include examination and analysis of your home’s air infiltration, heat losses through the building envelope, and HVAC performance. Professional energy audit tests include: blower door test, thermographic scan, duct leakage test, and additional tests. You can find professional energy auditors in your area, and also can conduct a do-it-yourself home energy audit.
Blower Door Test
After closing all ducts, windows, and doors in the building envelope, a large fan is installed at the main door to depressurize the house which allows air to enter through leakages in the building envelope. The test simulates the effect of a 20 mph wind on the building envelope. The blower door system measures air pressure difference between the inside and outside to determine the air infiltration rate of the home. If the test shows large air infiltration rates, the professional will then will use a smoke pen to locate these openings and recommend strategies to seal them.
A thermographic scan uses an infrared camera to determine where the largest energy losses are occurring through the building envelope. When used with a blower door test, thermographic scans are a powerful tool to determine the most effective places to implement envelope upgrades (windows, insulation, doors, and roof) to reduce energy losses in a home.
Duct Leakage Test
While performing a blower door test, energy auditors will check if your air ducts are leaking by performing a pressure pan test. To do so, the auditor will cover each duct and measure the pressure difference between the duct and the inside environment (which is depressurized to 50 Pa due to the blower door test). The higher the pressure difference, the higher the leakage to the outdoor environment.
Combustion Safety Test
Most auditors will perform a combustion safety test to see how efficiently the furnace is burning the fuel source, and if any leaks are present. In this test, the auditor will check the inside of the blower wheel and filter in your home's furnace to ensure that dust hasn't accumulated on either of the fixtures. Dust accumulation can have adverse effects on the air quality in the HVAC system, and will affect the performance of the system. Additionally, the auditor will go outside to the flue (combusted air) gas exit to read the composition of the flue gas as well as the temperature.
As an addition to the above tests, auditors look over your past energy bills, and check your heating and cooling equipment along with your electrical system to ensure safe and efficient operation.
To find professionals in your area, there are several places you may look to:
- Your state or local government energy office may help identify a company or organization that performs audits.
- Your electric or gas utility companies (Columbia Gas Energy Audit) commonly conduct residential energy assessments or have recommendations of local auditors.
- The Residential Energy Services Network provides a directory
Though less effective than a professional home energy audit, you can follow the below options:
These auditing techniques allow you to seal air leaks, ensure proper insulation, analyze the efficiency of your heating and cooling equipment, and examine your electronics and lighting within your home.
- “Energy Saver 101 Infographic: Home Energy Audit” by Department of Energy - Infographic of what energy audits include.
- "Home Energy Audits" by ENERGY STAR - Energy audit resources provided by ENERGY STAR
- “Home Energy Audits” by Building performance group - An in depth overview of what energy audits look at, including additional tests not discussed in great detail on our website. Additionally, a four part video series is included that takes you through each of the important energy auditing tests.
- “Professional Home Energy Audits” by Department of Energy - Short page on how to prepare for an energy assessment, how to find an energy auditor, and what to do before contacting an energy auditing company.
- “Home Energy Yardstick” by ENERGY STAR - Do-it-yourself energy audit resource
- “Do-It-Yourself Home Energy Audits” by the Department of Energy - A do-it-yourself resource that walks through how to: locate air leaks, seal air leaks, examine ventilation, check insulation, inspect heating and cooling equipment, appliances and electronic, and lighting.