from Terri in Green Bay, WI:
#410
Why doesn't our home air conditioning unit cool the second floor of the home? The main floor and basement are fine but the second floor stays too warm. The attic floor was insulated about 15 years ago, the exterior side walls were insulated about 9 years ago. We had a attic ridge vent installed about that same time.
There may be several reasons.
There may be several reasons why the second floor doesn’t cool properly. It could be something as simple as re-directing the air flow of the supply registers to “push” a bit more air to the second story (results in less air delivered to the basement and main floor). Since cooler air is heavier, it will tend to “fall” to the lower levels. This will probably increase your energy bill somewhat as you cool a larger area that was not being cooled previously.
Even though you had the attic floor insulated, it is probable that no attempt was made at that time to properly air seal many of the penetrations that continue to allow air leakage from your hot attic into the conditioned space of your home below the attic floor. Because of the (now) existing attic insulation, it becomes difficult to locate and air seal those penetrations effectively. One way to find out whether you have air leakage is to have a blower door test conducted. The blower door test is part of the in-home evaluation process with a Home Performance with ENERGY STAR® consultant. The consultant can determine approximately how much leakage is occurring between your home and attic, as well as the total leakage for the entire home.
With regards to the ridge vent: it is part of a system that can be effective in reducing the attic temperatures when complemented with soffit venting. Here is a link with an illustration to depict that scenario.
Published Wednesday, August 26, 2009