Home Repair

Why is my upstairs so hot?

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I live in a 2 year old home-- everything in it is brand new, in fact the a/c unit itself is less than 2 years old. The downstairs in the house is cooled great by the air-- no complaints, couldn't be better. However, the upstairs is always almost 10 degrees warmer than the lower level. I expect it to be warmer but it's really excessive. We tried closing off some of the vents on the first level and the basement and, no dice, it's still really hot upstairs. The house is well insulated so I don't think it's escaping.The vents are blowing strong too. It's driving me nuts!

A couple of people have given me these suggestions: get those little fans that go over the vents on the floor to pull the air up and circulate. To me, that didn't seem like it would solve the problem. Someone else also mentioned something about the heat in the attic not circulating, or something like that. As you can tell, I'm really mechanically inclined (Sad) so I can't even remember the rest of what that person told me. But, what are your thoughts on what might be causing it and how to make it cooler? It's been so humid lately, it's almost like I don't have a/c, which I feel is a real rip off since I do!

Hmmm. Do you have access to the attic? If the attic is super heated because of poor circulation, then that could cause the second floor to be hotter like that.
Since cold air sinks, the cold air that comes out of the vents on the second floor will sink to the first floor through the stairway. If you close off the vents on the first floor sometimes the air conditioner will have to run longer to get the thermostat to reach the desired temp. I would talk to an HVAC guy (or girl) and explain what is going on. They may be able to put in a flow booster in the line that goes to the second floor to increase the amount of cold air. You would only need this in the summer though so it would be tied in with the cooling part of your system and not the heating
Hey Butterstotch- I'm definitely NOT the Guru... but my folks have had this issue in their 3 year old townhome. The upstairs was hot in the summer, and the downstairs cold in the winter. Here's what they do- in the summer, they close all the vents downstairs forcing the upstairs to get all the cold air from the air conditioner. the cold air will migrate down stairs by itself, but it originates upstairs, making it much more comfortable. In the winter they do the opposite- closing all the vents upstairs alowing the warm air to originate on the ground level and rise up the stairs... Which is basically what Guru told you. Laughing It works really well in their home!!! good luck!

Karen Smile
Dear Guru,

We have a new unit ... 2 1/2 ton for 850 sq. ft. upstairs. This is a new upstairs apartment with a bedroom, bath, den and athletic closet. We have insulation in the walls and more than enough on the ceiling. We have turbins in the roof. The unit will not get it cool. Air coming out at the vents is 66 degrees. What do you think the problem is? Any help would be appreciated. Thanks
well here we go here is the problem solved, You do not have enough cold air exchanges at the top of the walls on the second floor and to much on the first floor.

In the winter the heat gets recirculated and re heated but in the summer the cold air exchanges must be at the top area of the wall or ceiling to bring the hot air back to the furnace / AC so it can cool it off, if the cold air return vents are on the floor area or bottom of the wall it is impossible to get the hot air back to the furnace /AC so it can be cooled simple problem

The way to fix this is to change the cold air vents at the bottom to ones that can be closed when needed, and cut new vents closest to the ceiling as possible just over top of the existing cold air returns that should be in every room in the house so make sure there is one in every room,

The new vents should also be able to be closed when needed so you can close them at the top in the winter and open the bottom ones and close the top ones so you don't suck up the heat and not the cold air that is at floor level in the winter...

Read a couple of times it will make sense !!! hope I helped I normally charge for these things at work so take this to heart!


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