Schmitt Heating's Blog
Your AC Window Unit Has to be the Right Size
Did you know that according to some surveys that have been done, most air conditioning systems are actually 50% too big? Yes, that's true, but in some ways, it is believable. It appears that some people think bigger is better. That is, of course, not necessarily the case. It's real important that you get an air conditioner of the right size. That can be determined by an air conditioning professional, although it is probably easier for you to find out for yourself if you are operating a wall or window unit.
You will need a unit with 10,000 BTUs to properly cool a room that is 400 square feet; that is, one that is 20 feet in length and 20 feet in width. For 600 square feet, you're talking more in the neighborhood of 14,000 BTUs. All this based on a ceiling that would be eight feet. And kitchens, because of the presence of appliances, takes more BTUs.
While you need the unit to be pushing out enough BTUs to do an adequate job, you also don't want to overpower the room with it. The more work the AC has to do, the more energy may be going for naught, and that is never a good thing. You need to get the right size unit for the room you're looking to cool.
There are some variables you can consider, or put in place. Remembering that if you are using a window unit in the first place the room can't be terrifically big, you have the opportunity to supplement the work you air conditioner is doing with a few other things. One of them is to ventilate through another window, if it is available, or the single window in the room, if you have a unitary system that goes through a wall opening and not a window opening. Another is to have ceiling fans and/or portable fans carry some of the load. One of the things you want to do is to make things as easy on that AC unit as possible, which in turn will make things as easy on your pocketbook as possible. This is not a bad way to do it.
If you are in small rooms, it is entirely possible to go with a wall or window unit and be quite comfortable. If you take the extra measures to go about it in the right way, you'll really be able to do so economically.