Tri-level home with one central AC unit...won't cool the upstairs?

Question

I have a tri-level home and the central AC unit won't cool the top level. Main level is kitchen, dining, living rooms, half bath, lower level is den and garage, and upstairs is bedrooms and baths. Den stays REALLY cool. Main level is pretty cool as well, but the upstairs is always about four degrees hotter than the mail level. You wouldn't think four degrees would be a big difference, but with temps. in the triple digits this year it did! There's a big difference between 85 and 89 when you're trying to sleep! Someone suggested installing a separate unit for the upper level. Someone else suggested replacing the current unit with a dual zone unit. My power bill has been $450 plus for the last few months. My house is pretty well insulated, so I really think it's just that the unit isn't proficient. It's not that old either and is serviced twice a year. Any suggestions??

Yes, there is an air return upstairs. I do use ceiling fans, but it doesn't seem to help. I also have no idea what "dampers" look like or where to find them. :*

Answer 1

We used to have a two story home with central air. Never was satisfied with performance.

Decided years ago that I wouldn't have central air again. Too difficult to cool upper level. Sounds the same as you.

Would rather have window air conditioners. That way you can regulate the air yourself. If upstairs isn't being used say during the day time hours then you wouldn't have to put air on until later.

Because of the shape (crank) of our windows, we have a floor model which exhausts the hot air out a small opening near the baseboards. It also has a dehumidifier unit build in the same unit. Nice feature for those really damp days, but cooler outside. Then we have small window unit in our bedroom.
This is our main living area. No two story anymore.

We do have a lower level (finished) basement with three bedrooms, 1/2 bath and living area. Obviously, we don't need air in this area.

Upstairs the ceiling fans are always running for air flow. Now have ceiling fans downstairs also. Ceiling fans make a big difference during the summer and winter. They are all reversible fans.

Window air conditioning for me. That's the way to go as far as I'm concerned.

Niece also has two story with same problem. She has a large home and should probably have another unite. However there bedroom is on the main floor, but it gets warm upstairs. That's just the way it is with two story homes and air conditioning unless you want to double you money and get another unite.

Answer 2

If after finishing your basement the upstairs is not cool enough you could try cutting back some of the vents in the lower floors to push air upstairs, you may not need to close off too much air, just enough so that the unit cooling stays on a little longer. If that does not work then you would probably have to increase the indoor and outdoor units with larger units and more capacity. Depending on how your duct is run it may be hard to install a second unit for the upstairs.

Answer 3

First off it is simply put Your roof is too hot and something called conduction causes heat to come through anything it touches. Hopefully your ducts do not go through the attic and down throught the ceiling.

A attic fan helps slightly but if you really want results you will need a sprinkler system installed on your roof. Sounds funny but they have been in use since the 70s. People have seen as much as a 50% savings on their utilties.

The sun heats up those nice black sun absorbing shingles on the roof. They heat the wood beneath it. That heats the attic, which in turn heats your top floor ceiling. THIS is the real reason the upstairs is always hotter.

Attics get up to about 190 degrees in the summer. With a water system they usually stay about the same as the outside temperature. Instead of wasting money on a 2 day project by a heating cooling man, spend a little money on a energy saving idea.

Answer 4

First-Do you have a return air in the upstairs? Most older houses were not ducted with a return air upstairs. The old fix was a hole through the floor. Also you can install dampers in the duct and adjust the air flow to get more air upstairs. This will not help much without a return though because you have to remove the humidity from the air by pushing it through the AC coil. If you install a return air it will fix the problem. Also ceiling fans aid in mixing the air.

Answer 5

I have a 2 story with central air, and originally the same problem.
Up in my attic, coming off the main cooling coil, all the duct work branches off to different parts of the house. On each on is an internal flapper valve. On mine, I loosened a external wing nut, allowing the internal valve to be moved. I adjusted valves so more air was going upstairs than downstairs, then tightened the wing nuts to lock valve in place.

Answer 6

I had the same problem in Ohio. I installed a roof fan to increase the air flow through the attic. I was surprised how much this helped. Also closing vents in the den will allow that air to go elsewhere, hopefully upstairs. Also switching your furnace fan to run continuously can help.

Answer 7

Unfortunately, your problem is down to simple physics, hot air rises... So however high you turn up the A/C you're not going to be able to easily cool the upper level.

So, it's reasonble to think that your exisitng A/C could cool your house without any problems, maybe it just needs moving to the upper level.

Answer 8

If you look, most homes have dampers in the output side of the duct work. A lot of homes with different levels have a big damper on the output side.....You can adjust these to send more air to certain rooms....works better than closing off registers in certain rooms. Your problems sound typical....just find the dampers and send the cold air to upper area....works fine for us around here. Then in the winter...send the heat to the rooms you want it.

Answer 9

Trilevel Home

Answer 10

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