Air Conditioning - Sizing bedroom window ac and recommdtns

I need help on determining what I need in a new AC. The room is basically 12 x12 , with 9 ft ceilings. One wall was made into a closet, of close to 2 ft in depth, with louvered doors which I frequently don't close. Above the closet are large storage spaces with no doors because I removed the ugly sliding panels that had been installed. I throw things like blankets and suitcases up there, but it isn't full. Part of this adhoc closet (not my idea, folks; it was there when I bought the house in 1979), is the house's chimney, which runs pretty much right thru the middle... an awkward and space consuming arrangement at best. This is a Philadelphia row house, 2 story, early 20th century construction, if that matters.

There are two east facing windows of about 15 square feet each. Previously I had an 8000 BTU Emerson "quiet cool" AC in one, but it stopped being quiet (or I got more sensitive to it), I couldn't sleep, so I got rid of it. One of the things it did was to cycle on and off a lot, which I've read is a sign of an oversized unit.

Different people and calculators recommend different capacities so I don't know what to believe. I also don't know if my perception of the 8000 BTU as too much for the room is correct, since one of the applicance stores asked for the basic room dimensions and immediately said I need this much capacity. They never asked (and neither do some online calculators) anything about the ceiling height or the window sizes or which way they faced. Online calculators generally come up with capacities more towards the 5000 BTU, but I think that's pushing it.

1) Should I include the odd ball closet in the dimensions of the room to be cooled, regardless of whether the bottom doors are open or closed, since the top is always open (altho not needing cooling, of course)? Would you subtract the space the chimney takes up?

2)Do the windows or ceiling height make a difference in the calculation?

3)Did the on-off cycling of the previous unit indicate what I have come to believe? I'd rather have something consistently on at a low level instead of starting and stopping frequently.

4) what recommendations can you give for the quietest, but still well made (if there is such a thing these days) unit? I've seen online praise of a brand called LG, which I've never heard of.

Thanks for your help.

jo

One of the books I have on window AC Say for a 200 sq ft room 6,500 btu. For high ceiling add 10% and for a Sunny room add 10%.
With the AC you do want them to run longer and not be so big that it turns on and off right away. When they run longer they get the humidity out of the room and you feel cooler at a higher temp.

ED :thinker:

4) what recommendations can you give for the quietest, but still well made (if there is such a thing these days) unit? I've seen online praise of a brand called LG, which I've never heard of.

Thanks for your help.

jo

Good luck. That's why we call them window shakers :D. LG is what used to be called Goldstar. They make a good unit. Just remember you get what you pay for. If you go to Wally World and buy the $88 dollar unit don't expect it to be quiet for long.

I'm a little confused. You say Lg makes a good unit but everything else you wrote was negative. Are you saying the cheap LGs are bad, but the higher priced ones are good?

I've had a sharp 5000 btu electronic model for years. It's as quiet as I'd expect a window unit to be. I think it was around $150

I'm sorry if I confused you. I meant that LG makes a unit that will last.

Any window unit regaurdless of brand, the cheaper ones are made of weaker cabinets and less insulation causing them to start rattling after a while.

It will also depend on the window. If you have the old loose double hung windows you'll get a good rattle and a nice heavy window you may not hear it at all, even a cheaper model.

Buy what your budget will allow and if it's to noisy take it back to the store and try a different one.

Thanks for the clarification. The noise wasn't from the window (at least I don't think so). I have wood windows, pretty decent, although not brand new by any stretch of the imagination. The noise I was hearing was the ac motor-- I think. Could I be confusing it with something in the window? Also, the starting and stoping probably accentuated my sensitivity to it.

I'm really confused by the BTU estimates I'm getting from the stores. They invariably whip out 8000 BTU, which doesn't correspond to charts for my room measurements .... more like 6500 BTU. They also don't ask about ceiling height, window size or direction. What's so unique about 8000 BTU? Is there more of a markup on that size than the smaller capacity units? 8000 is what I had before and I intuitively feel that the motor noise and on /off cyclcing was related to it being over powered for the room.

jo

You probably were hearing the compressor and fan motor. Being that they are housed together they can make some racket esspecially after a few years of service. Here is a sizing chart for window a/c's. If you want an exact heat loss calc there is one here and if you follow the link correctly I think there is a one time free trial version. http://www.hvaccomputer.com/



Area in
square feet Btu/hour
100 to 150 5,000
150 to 250 6,000
250 to 350 7- 8,000
350 to 400 9,000
400 to 450 10,000
450 to 550 12,000
550 to 700 14,000
700 to 1,000 18,000

That's basically the chart I have too and I don't come close to being inthe 8000 BTU range. The room is 12 by 12 with a 2 ft closet on one wall which, since it's always open, you could say 12 by 14 at best. I have 9 ft ceilings and 2 east facing windows in Philadelphia. Even my neighbor has a 6500 and her bedroom is basically the same.

I think the main noise that bothered me was the on/off cycling which was happening much too much. I want a steady level of both noise and cooling and would rather run the unit at a low level all night than have it start and stop.

Thanks for the link.

jo