Components of HERS Ratings Pt. 3: Insulation Inspection
Continuing with our series of blogs on HERS ratings components today we focus on the importance of the insulation inspection. In this part of the HERS rating the rater will check for effectiveness of insulation in walls, ceilings and floors above unconditioned spaces such as crawl spaces and garages. The insulation inspection is part of the HERS rating for both new and existing homes.
The HERS rater will check for gaps, voids and compression in insulation to determine effectiveness. This is done before the drywall is hung in new homes so the rater can fully assess each exterior wall within the home. Areas like wall cavities that contain wiring and other hard to insulate around items are especially important. It is crucial for the rater to verify that batt insulation has been cut to fit neatly in each wall cavity. If this is not done, compression could occur, rendering the insulation less effective. It could also mean gaps occur within the cavity as seen in the image below. Notice the void around the electrical outlet.
This picture illustrates typical compression that may occur if batts are not fitted around wiring.
Blown in insulation is a better option for insulating around these hard to fit areas, however the rater must then do a density test to make sure the wall is not over or under blown.
In existing homes infrared can be utilized to verify wall insulation. If an infrared camera is not available the rater may use a wooden rod or other probe-like item that will not conduct electricity by removing an electrical outlet cover and probing around the area for evidence of insulation. This however, is less conclusive. As you can see in the picture below, the infrared camera is able to pick up thermal deficiencies within a wall cavity of a finished wall.
The above picture indicates there is insulation missing within some wall cavities of this particular home.
The rater will also verify that the attic is insulated to the appropriate level for the climate zone the home is located in. Crawlspaces, floors above garages, attic knee walls and any other area of the home that is connected to an area of unconditioned space (i.e. rooms with floors above porches) are also inspected ensuring the home has a complete thermal boundary.
Whether your home newly built or it is a hundred years old, knowing the effectiveness of the insulation is important to your home’s efficiency. Contact us today to schedule your home energy rating.