A/C unit for small house

House I'm renting is about 800 square feet and needing to throw a window mounted air conditioner in for the summer. I have a small 5,000 btu A/C unit available that is only a couple years old. The house has two big maple trees on the west side that will shade the house during the latter part of the day. I'm not looking to turn the house into an ice box, just remove the humidity and cool it slightly for sleeping. Could I get by with this A/C unit and some fans to circulate the air?

(quoted from post at 11:14:07 05/06/12) House I'm renting is about 800 square feet and needing to throw a window mounted air conditioner in for the summer. I have a small 5,000 btu A/C unit available that is only a couple years old. The house has two big maple trees on the west side that will shade the house during the latter part of the day. I'm not looking to turn the house into an ice box, just remove the humidity and cool it slightly for sleeping. Could I get by with this A/C unit and some fans to circulate the air?

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had one of those little 5000 btu units once, in a bedroom of 300 sq ft & about all it did was make noise & cool my face if sitting close enough to blow directly on me. There are of course many, many variables, but as a 'general' rule of thumb, you need about 12,000 btu per 500 sq ft.

50000's seem to be quite disappointing in most cases, except for one small room. We have an 8000 in our cabin on the Canadian border (500sq ft) and it is just right. There is not that much difference in power consumption and the newer ones are very efficient.

One that size will help but will be over worked and not do a very good job. A unit like that will do the bedroom and that is about it

The unit was in the window of a bedroom that was about 180 square feet at the previous house and it did a good job at that task. I had a feeling it probably wasn't going to be large enough to do the job but figured I would ask more knowledgble folks. Thanks for the help guys, I'll be looking for a larger unit to throw in the window.

Rich, we have a small house like yours and for the last 2 summers we cooled the main floor OK with one 6,000 BTU window unit...BUT our house is square and has doors in appropriate places to enable 2 fans to blow it from room to room (sort of around in a circle through the house).

This year we just bought a 10,000 BTU free-standing unit that you just vent its exhaust hose out your window (I presume to get rid of the heat created by the unit). Cost was $299 - has remote control and is self-evaporating regarding the moisture. When it is running, it should be like Alaska in here. When it is not running, we will be free to open all the windows for cross-ventilation as none will be plugged up an AC unit.

Rich, the 5K is too little. Before you buy anything else, what does your electric system look like, old wiring, outlets (2 vs. 3 prongs, your breakers, loops etc.
Assuming that the above is ok, you want to have at least 2 units on separate breakers and 110, unless you have a 220 outlet.
http://www.goodhousekeeping.com/home/air-conditioner-calculator
There are many, just pasted the first decent one for you.
Slightly larger is better, be sure it is energy star compliant. And don't forget to support large window units from the outside with blocks or a pole/post/2x4/ etc. Insulate well around ac opening in window, they make foam/etc. pieces for that or do your own.

Hello Rick Iowa,
Like JMOR said 1 ton or 12000 btu's per 500 square feet, is a good rule of thumb.
It is also assumed that the space to be conditioned has an 8 Ft. ceiling.
Ceilng fans will help quite a bit. Also.
Power attic ventilation would help the air conditioner as well, they are, as a rule a thumb, worth about 6000 BTU's of cooling.
Guido.

It's all about the unit and it's efficiency and where/how you are going to use it.

The list goes on with what is the circulation foot print, what kind of insulation do you have, you hit part of it on the tree shade, where will it be located with respect to prevailing winds and sun rise and set, what kind of heat load are you going to put on it with people, cooking and the like, what kind of electrical capacity do you have where you are going to mount it?

The big chain home improvement stores have some really nice, efficient units, at very accommodating prices. Get the highest EER you can without going nuts on the price, and don't get the combo heater/AC if you can help it. The AC will wear out B4 the heater and you spent a lot of money for nothing (my opinion).

And last, get one with electronic controls.....no knobs, just LED lights and push buttons. The reason is that the compressor cycling is controlled with electronic circuits, not manual sensors and mechanical relay contacts. The temperature is maintained much better and the thermostat doesn't wear out because it has no mechanical contacts......in the past, the first thing to fail on any AC, Ref, freezer I ever had.

I'm not going to suggest a rule of thumb size or brand. Best bet is for you to go to a big builders supply and buy one with a customer satisfaction tag. If you don't like it you can bring it back, get your money back and move up (probably) to a higher cooling capacity unit.

But I guarantee you a 5k is too small to do much of anything with other than cool your bathroom.....if it isn't too large. BTDT

HTH,
Mark

Oh, don't dilly dally about getting it. In the spring they have them piled 6' high on pallets in the front of the store. Before summer gets rolling the pallets are empty and the AC's are just a fond memory. BTDT too.

Mark

Yep larger is better. Then you're not comfy cause it got cold but did'nt 'DEHUMIDIFY' (get the water out). Size for the intended result, bigger is not better always. XWZPDQ websites, do this or that. Check with someone in your climate/area that knows what works where you're at.

(quoted from post at 18:44:23 05/06/12) Yep larger is better. Then you're not comfy cause it got cold but did'nt 'DEHUMIDIFY' (get the water out). Size for the intended result, bigger is not better always. XWZPDQ websites, do this or that. Check with someone in your climate/area that knows what works where you're at.

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n all fairness, he did say 'slightly'......"Slightly larger is better,...."

This house has 3 prong outlets, some newer wiring. I'm renting the house from a buddy, when he lived here he had a huge old window unit that never caused any problems. I figure if the system can handle an old energy hogging unit like that, a new one should be no problem at all.

I will be doing something to insulate around the AC unit, those thin plastic flaps that are included are just about worthless.

It's just me here along with the dog. So there won't be much of a heat load as far as people and kitchen use go. I also use the couple ceiling fans and have a portable fan to keep the air moving, which I know helps. Like I said in my original post, I don't want to make it super cold. I try to save money and keep it comfortable at about 76 degrees or so but not freezing.

I installed the unit this afternoon and let it run for a few hours while I was out mowing. It didn't make the place much cooler (brought thermostat down a couple degrees to 74) but did seem dryer. When I was home I noticed it was not running constantly, but it's not 90 degrees out with 80% humidity either. I'm going to take a look while in town tomorrow to see if there are any deals to be had. Think if I get another 5,000 btu unit and put it in the bedroom, the two of them will create a circulating effect because they would be in opposite corners of the house. If I do find a bigger one, that be fine too.

Rich, go with something SLIGHTLY larger than exactly 5000 btu. 5100, or 5200, and the prices of a 6000 btu unit is literally a handful of dollars more. On superhot days, you will appreciate the extra.... A lot of the small units can be had with a little remote, bought a Haier 6K, digital E-Star compliant unit a couple yrs ago, love it. I think from WalMart or Lowe's or HD...
If you think about adding any insulation to the house, attic insulation gets you the most bang for the buck, year round....and well sealing windows and doors as well.

Lowes has some 6,500 and 8,000 btu units I'm going to look at tomorrow.

Good luck. BTW, if you have a Lowe's card and charge it, they give you 5% off right-away, even if you pay the bill in full when due... saves a little extra!!

I was in Lowes a couple of days ago and yepper, they're down here too. As I said, leave the ones with knobs alone. Get the ones with electronic controls; you won't regret it.

Insulation is priceless for these little critters. A lot of houses down here that were not built to be air conditioned have no insulation in the ceiling nor in the walls. Even if you can insulate the ceiliing with 4 it will help. 6 is much better. Other than air entry/exit, most of your heat absorption (cooling loss) is through the ceiling....attic is hot and square footage is large.

Certainly fans help and having another just doubled your capacity and as you said your circulation.

You have to realize that the price of the unit is a one time event. The light bill and the comfort is with you all summer long.

For the record, I built my house, insulated it as best I could, use ceiling fans and an attic fan (in season) and have window units. I prefer them over central as they are more efficient for several reasons:
Cycling efficiency is higher since the distance is much shorter.
The condenser coil gets splashed with liquid condensate (water) from the evaporator coil making head pressure and power consumption much less.
They are much cheaper to purchase and last as long as a central.
You don't have the heat loss of all your ducting in the 140 degree attic with just 1" of insulation around it.
If you don't use an area just turn off the AC and close the door.

Course I built my house to be cooled with window units. Obviously everyone is in a unique situation that has to be handled accordingly.

I use gas for clothes and heating in season.

My highest light bill last year was during the August drought with a month or so of 100+ ambient temps, and I consumed 1736 KWH of electricity with a 2400 sq ft house. July was 1302 KWH and June was 1125 KWH. We buy it from our local coop for $15 plus $0.114 per kwh with no fuel surcharge.

Mark

My brother had central air installed, and we
went to a birthday party and couldn't stand it,
his house was so hot, and i was wipen sweat the
whole time..He complained to the dealer who shrugged, and said: "it was SIZED RIGHT for the
house".
I'd rather have a large unit loafing, and be cool
than have a small unit working itself to death,
and not keeping up!

I have a 5k unit that works fine in a 16x16 living room and you can open the door to the kitchen and still be comfortable.I use the air conditioner on the worst days.People seem to go nuts with air conditioners,They want the house 60 in the summer and 85 in winter.When the heat really bothers me I turn on the air conditioner.Power usage is not bad on a 5k.I still work outside so I dont like to be overcooled.Cant stand stores that are freezing in summer time,too much shock when you go outside.