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OT - window units vs central air

Plum Street

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Jun 21, 2009
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Have central air now in the house with 3 floors to cool. Two rooms upstairs still don't really get cool until the sun goes down. Sometimes I miss the days when I lived with mrs . Plum in a small ranch and one big window unit cooled the whole place .
 
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Maybe your central ac isn't sized properly for your home, or your home isn't properly insulated.

Try closing vents on the lower floors to force more cooled air upstairs. You can also try closing doors upstairs to trap the cool air up there (since cool air will settle down the stairs).
 
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Maybe your central ac isn't sized properly for your home, or your home isn't properly insulated.

Try closing vents on the lower floors to force more cooled air upstairs. You can also try closing doors upstairs to trap the cool air up there (since cool air will settle down the stairs).
Could be insufficient attic insulation above the two rooms that are not getting cool. That's a pretty easy fix. Also, if the attic is not properly ventilated, this could add to the problems.

A good compromise between central AC and window units are split systems, where a cooling unit is mounted near the ceiling of a room on an outside wall, and a condenser is mounted outside.
 
Like @Knight Shift said, you might need one of these....

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If you have an old house retro fit with CAC it's tough to get it to work right. My neighborhood is all 1940s capes (attics converted to second floor living space) and you have to cool from the top down. That means the air handler and thermostat are upstairs. I often close 1/2 the vents downstairs and the cooling is pretty balanced. Remember that in addition to blowing cool air, CAC will also suck out and dehumidify the warm humid air so you also need a lot of returns upstairs.

If your cooling is with your furnace in he basement and thermostat is on the first floor, you're going to have problems. Expensive solution is get multiple zoned system. Middle of the road would be get a ductless system upstairs. Cheapest is to throw some window units on the third floor during the hottest months.
 
Have central air now in the house with 3 floors to cool. Two rooms upstairs still don't really get cool until the sun goes down. Sometimes I miss the days when I lived with mrs . Plum in a small ranch and one big window unit cooled the whole place .

Close of some of the lower vents and open all the upper level ones. Cool air settles.

Also make sure you have a return upstairs to suck in the warm air that rises and close off any lower level return.
 
I have central air that needed help, so my ac guy suggested
fujitsu mini-split for 2 bedrooms upstairs, where the central was
not so effective.....if you are not familiar, this is both ac and
heat unit that is put into your wall, with a condenser outside, but much smaller than a standard ac ......

I shut the vents off in the two bedrooms for the central air and use the mini-split alone when I am using those rooms

..... this keeps the bedrooms cool in the summer, warm at night.....and I figure it makes it easier for the central air not
have to cool those two rooms
 
I have two zones (basically two central air units) one does upstairs and one down stairs. They run independently on separate thermostats. Works great.
 
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