When it's hot it's hot!

[Dolemite1971]

Hello I am a home owner and my question is during the heat of the summer when temperatures are at 90+ degrees my HVAC system located in the attic is not keeping the upstairs cool at all. It just hovers around 80 degrees until it cools off outside and then the temp gradually comes down. Is this becasue my HVAC system is not sized properly, improper circulation of air in the attic, or do my ducts need cleaning. The house was built in 2001 and I bought it in 2006.

[ar_hvac_man]

COuld be too small. Might not be working properly. Hard to guess. Have it checked out by someone local.

[gary_g]

The heat load on the home is more than the system can handle.

There are a variety of reasons: outdoor max design temp, indoor min design temp, air handler location, insulation, windows, ductwork design/leaks, refrigerant charge, system sizing, 2 systems needed and only have 1, dirty coil, dirty filter, dirty mind, ..........etc.

Good luck.

[ar_hvac_man]

The heat load on the home is more than the system can handle.


.

Maybe, but how can you be certain?

[gary_g]

Maybe, but how can you be certain?

The OP states that his problem occurs at 90+ degrees outside.

It's hard to tell from cyberspace, this is why I listed many of the possibilites.

[beenthere]

Do you have one or 2 A/C systems. If 2, what temp do you keep the first floor.
If one, what temp is it keeping the first floor. Are you using a set back stat, and letting the temp get high before turning the A/C on.
Has the unit been serviced this year yet. Have you checked or changed your air filter recently.
Has your house alway had this trouble since it was built.

[Dolemite1971]

I have a basement unit, a middle floor unit, and a upstairs unit. The problem has just started within the last year of buying the house. I bought the house in 2006. I have not had it serviced this year, and I have changed the filter. I try to keep the middle floor the same temp as the upper floor at 74 degrees. However the middle floor maintains it ok but not that great, and the upper level spikes to about 79 and stays there until it cools down in the evening. The attic where the unit is located for the upper level gets really hot during the heat of the day. The thermostat is one of those programable controls that you can set the temp according to the time of day or you can hold the temp constant through out the day. I am having a HVAC tech come over on Thursday.