Increasing Cooling Capacity

[RGC]

I'm looking for advice to improve the cooling on my home. The house is 9 years old and built using an EWC NCM-300 control and three zones. We are in Boise ID and I was told that they designed my home cooling for about 93 degrees outside and we often see temperatures over 100, with an occasional 110. The house has a single 4-ton system. When the outside temperatures get over 93, during the hottest part of the day, I don't have the cooling capacity to keep the upstairs zone cool. My master bedroom is downstairs and on it's own zone and there just doesn't seem to be enough cooling to run all three zones and keep the upstairs cool. Often at the hottest part of the day, with the upstairs zone set on 78 the temperature upstairs will be 80 or 81 and cooling running continuous can't get the upstairs down to 78. This then makes it hard to keep the downstairs cool as well, as the main air return is upstairs.

I'd like to replace the system with a 5-ton more efficient system, but don't know how to tell if that will do the trick and improve upstairs cooling when the outside gets really hot. The home has 2x6 construction and good windows and insulation. I've had my local HVAC people do everything they can think of to improve the existing system. (Had the ducts cleaned and sealed and the sealing process fixed major leaks and was supposed to make significant improvements in system performance.)

Just wondering if others have had success going to a larger system with no other changes to their home, in solving this problem, or are you just suppose to live with it, when the outside get's unusually hot? The home seems to cool fine if the outside temperature only gets up to about 90 degrees.

[Paul Z.]

You can call the office 1-800-446-3110 X490. We can then talk about your problem and maybe give you some help.