Two ac window units instead of one large one

Old 04-23-19, 07:37 AM
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Two ac window units instead of one large one

I have a large room (about 16 x 24). I have a bow window on one side which I obviously can't put an AC in. The other side has two double hung windows close to each other. I would prefer to use a 600 btu ac in each of these windows (I already have these) opposed to buying one large heavy weight unit. It would be easier for me to put in and take out two instead of having to get someone to put and take out one heavy unit.

Your advice is much appreciated!

Old 04-23-19, 08:20 AM
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So your question is whether you can do this?

Have you determined how much cooling the room actually needs?
Old 04-23-19, 08:43 AM
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If I bought a large one it would be approximately 10,000 BTU. As I stated the room is 16 x 24 . Two of the smaller units (5000) each would be the equivalent of 10,000 unit. I'm trying to avoid buying the large, heavy one. I am a small woman and don't like to bother anyone to install and re-install this for me. I can handle a 5,000 btu unit.
Old 04-23-19, 09:17 AM
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What is your question? Are you asking which would be less expensive? Are you asking how much light a 5'000 btu AC is versus a 10K? Are you asking which would cool better?
Old 04-23-19, 10:44 AM
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6000 BTU's might cool the room. Id try one if it dosen't work put the other in.
Old 04-23-19, 02:19 PM
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The sizing charts are not accurate. You probably don't need 10k btu and 6 to 8 will do.

If you truly need the capacity, putting in two smaller units is a good idea because you can run only one when it's not that hot, resulting in longer compressor cycles and better dehumidification.

Each unit must be on it's own circuit though.
Old 04-23-19, 04:28 PM
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What is your question?
She wants to know if two 5,000 units will cool the same as one 10,000 because she can't pick up and install a 10,000 by herself.
Old 04-24-19, 04:59 AM
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I think USER10 has the best answer. But the down side I think is running two units is less efficient and being able to provide two separate circuits could be a show stopper. Also light will be reduced and noise level will be much higher than just one unit of the proper size.

Just for the sake of argument, have you ever considered a whole house A/C unit? The benefits are complete air conditioning throughout the house and less noise, no seasonal removal and installation of units and clear windows. Yes, initial cost may be high but considered it a long term investment and home improvement. And will last longer than window units. Window units will only have an average life span of about 5 to 7 years. Again just for the sake of argument.
Old 04-24-19, 06:02 AM
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Even with whole house A/C, some rooms will not be comfortable. Have you looked at a permanent minisplit for the room? It will heat and cool to whatever temp you choose. Also they are much more efficient and quieter than window units. Resale is better too.
We had them installed in all of our upstairs bedrooms.
Old 04-24-19, 10:41 AM
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if you care about comfort and noise, a mini split is more expensive than a window unit, but it's a lot more quiet and also more efficient. I believe in the long run it is actually cheaper to have a minisplit, by reducing the electric bill. plus it doesn't take space on the window, it only needs a hole in the wall about 3", and most minisplits also works as winter heaters

the actual cost of a small minisplit is not that much more than a window unit, however it's probably something you don't want to install yourself, and many installers ask for a lot of $$$ to install a minisplit here in CA. it doesn't cost you much to just ask for a quote over the phone to a local installer where you live though. if you find an affordable one it'd be a better choice if you can afford the upfront cost
Old 04-24-19, 01:11 PM
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The problem the OP has is she already has these two window units. She does not want to spend money one more A/C units. That's why I suggested a long term investment on a whole house A/C. Maybe try to sell the two window units.
Old 04-24-19, 04:16 PM
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I should have stated in my original post three things: 1. I have hot water heat, so you would have do duct work 2. I am hoping to move in about a year; 3. Not worried about electrical costs-my electrical bills are low
Old 04-24-19, 04:49 PM
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Everyone here is just trying to give you relevant info based on their thoughts & the over all situation.
Personally, I think the two units will be fine in your specific situation. Its not ideal but neither is your situation so you have to do what you have to do.
My initial though is that, it would be better if you put one AC at one end of the room & one at the other end. I may be wrong but my thinking is that each AC has teh thermostat built into the unit. The thermostat is what tells the AC how cool the room is & tells it when to cut on & off. If both units are in the same window, it may cool that end of the room & cut off before the other end of the room gets cool. Having said that, I would suggest maybe using the setting that makes them run continuously.
If you have ceiling fans, turn those on to move the air around.
Old 04-24-19, 05:36 PM
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Lesser weight making for easier installation/removal in spring/fall is a perfectly good reason to use two 5000 BTU units as opposed to one 10000 BTU unit.

But I have the suspicion that the two 5000 BTU units will consume a little more power compared with the one 10000 BTU unit for the same amount of cooling..

I am guessing that the two smaller units both at the same end of the room will result in roughly the same unevenness of room cooling compared with the single larger unit.
Old 04-24-19, 06:48 PM
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My first suggestion would be to put both on the shady side of the house, if possible.

Set them to different temperatures, I guesstimate at least 3 degrees difference to keep them from short cycling each other. I would set the lower temp unit to economy/power saver mode, leave the higher temp unit in normal mode. Idea is that
one unit will do the initial cooling, but once it gets hotter, the second unit kicks in.

I would set one unit to fan-on to circulate the air, probably the AC unit set to the higher temperature, while the lower temperature unit set to fan-auto.

Swap the settings every few weeks to even out the runing time/wear and tear on the AC units.

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