A home energy audit can help you understand the whole picture of your home’s energy use, comfort, and safety. An assessment can help you determine how much energy your home uses, where your home is inefficient, and which problem areas and fixes you should prioritize to save energy and improve the comfort of your home.
A home energy assessment should be your first step before making energy-saving home improvements, as well as before adding a renewable energy system to your home.
A professional home energy assessment will provide a thorough analysis of your home’s energy use. In addition to a room-by-room examination of the home, a home energy professional may use equipment such as blower doors, infrared cameras, gas leak and carbon monoxide detectors, moisture meters, and non-toxic smoke pens.
Blower Door Tests
Home energy professionals use a blower door as a diagnostic tool to determine how much air is entering or escaping from your home.
Professional energy assessors use blower door tests to help determine a home’s airtightness. Utilizing the diagnostic information provided by the test to identify areas of air leakage in your home and make energy-saving improvements.
These are some reasons for establishing the proper building tightness:
- Reducing energy consumption from excess air leakage
- Avoiding moisture condensation problems
- Avoiding uncomfortable drafts caused by cold or warm air leaking in from outside
- Controlling outdoor contaminants, pests, and odors from entering your home.
- Determining proper sizing and airflow requirements of heating and cooling equipment.
- Determining whether mechanical ventilation is needed to provide acceptable fresh air and maintain indoor air quality in your home.
While the blower test is being conducted, the analyst may use an infrared camera to look at the walls, ceilings, and floors, to find specific locations where insulation is missing, and air is leaking. The analyst may also use a nontoxic smoke pencil to detect air leaks in your home. These tests determine the air infiltration rate of your home, which is recorded on a laptop or tablet.
The blower door test is conducted as part of the energy assessment of your home. Your contractor may also operate the blower door while performing air sealing (a method known as blower door assisted air sealing), and after to measure and verify the level of air leakage reduction achieved.
Thermographic Inspections
Thermography measures surface temperatures by using infrared video and still cameras. These tools see light that is in the heat spectrum. Images on the video or film record the temperature variations of the building’s skin, ranging from white for warm regions to black for cooler areas. The resulting images help the auditor determine whether insulation is needed. They also serve as a quality control tool, to ensure that insulation has been installed correctly.
A thermographic inspection is either an interior or exterior survey. The energy assessor decides which method would give the best results under certain weather conditions. Interior scans are more common, because warm air escaping from a building does not always move through the walls in a straight line. Heat loss detected in one area of the outside wall might originate at some other location on the inside of the wall. Also, it is harder to detect temperature differences on the outside surface of the building during windy weather. Because of this difficulty, interior surveys are generally more accurate because they benefit from reduced air movement.
Thermographic scans are also commonly used with a blower door test 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.
Thermography uses specially designed infrared video or still cameras to make images (called thermograms) that show surface heat variations. This technology has several applications. Thermograms of electrical systems can detect abnormally hot electrical connections or components. Thermograms of mechanical systems can detect the heat created by excessive friction. Energy assessors use thermography as a tool to help detect heat losses and air leakage in building envelopes.
