Of all the places in your house to increase energy efficiency and comfort level, the attic is the easiest. But how do you know if you need more insulation? This is easy to determine with a visual inspection of your attic.
The two things you want to look for are density and distribution. Do you have enough insulation in your attic, and is it spread evenly throughout your attic? You can determine your insulation density first by just gauging how much you see. If you can see the floor joists in your attic, you probably need to add more insulation.
How much? R-Value is the measurement for insulation’s thermal resistance. Your insulation’s R-Value will determine how much of it you need to lay down for max efficiency. The EPA has made recommendations for R-Value based on region. For instance, a Tempe attic with an existing 3-4 inches of insulation would require R25 to R38. There are many types of insulation with different R-Values and thicknesses. Your goal is to build up enough insulation to achieve that R-Value. Going past that R-Value yields little benefit, though. Keep in mind, R-Values are additive, so you can mix and match insulation to reach your R-Value goal. There are two caveats to mixing insulation types: One, loose fill insulation requires a blowing machine for application, necessitating a professional; two, if you lay fiberglass over loose fill, it needs to be “unfaced” fiberglass with no backing.
Your final consideration for insulating your attic is distribution. Is your insulation evenly spread around the attic? Again, you can use the joist test. If you see joists in some areas and not others, you need to redistribute to those areas where the insulation is deficient. Generally, insulation is adequately high in the easy to reach places, like the middle of the attic, and insufficient near harder to reach places like around the eaves.
Wolff Mechanical has been serving the Phoenix area with an A+ rating from the BBB for over twenty years. For more expert advice about insulation, energy efficiency, or other comfort system issues, please contact us.
Our goal is to help educate our customers in the Phoenix Valley area of Arizona about energy and home comfort issues (specific to HVAC systems).