How To: Buy An Air Conditioner

Dept. of Cool. As summer approaches and all those AC's that have been languishing on Craigslist all winter look a lot more palatable, we thought it would be good to get out some tips on air conditioners. Who better to turn to than a fellow who has become an avid reader and sells lots of them, Levi Capland.

While he is totally biased as to WHERE you buy them, he is totally objective when it comes to HOW to buy them. This is what he says:

A. The goal is to buy an efficient unit that will cool the room using the least amount of electricity.

B. Know what you need. Figure out how many btu's your room requires.

Simplest way to do so is length x width x 35=btu's. Or sq ft x 35.

If you have high ceilings, are on a high floor of a bldg, have a kitchen attached to the room you are cooling, or get a lot of sunlight you want to multiply by 45.

C. Buying an undersized a/c b/c its cheap will save you in the short run, but you pay a lot in the long run. If the unit you buy is not strong enough to cool your room, all you will end up doing is paying very high electric bills. If it is too strong the unit will simply freeze over.

D. Energy Star units will save you about $15.00 in elec. bills per season. The higher the EER (energy efficiency rating) the more energy efficient the unit is.

E. With the exception of one model by Airtemp, all a/c's over 15000 btu are 220 voltage. Airtemp makes an 18000 btu on 110 voltage.

F. If trying to cool off more than 1 room, take into consideration that the further the cool air travels the faster it drops.

G. I see too many people trying to buy a 5000 btu unit for a 250 sq ft. room. I tell all my customers who are insistent on buying what they want (not what I suggest) "I will sell it to you, but I will not guarantee it to work for you."

Levi Capland (718.252.4000 ext 118)

Comments (4)

Ask anyone who really knows AC and they will tell you that buying and oversized AC is just as bad as an undersized. This from Energy Star:

Properly Sized Room Air Conditioners

"Many people buy an air conditioner that is too large, thinking it will provide better cooling. However, an oversized air conditioner is actually less effective — and wastes energy at the same time. Air conditioners remove both heat and humidity from the air. If the unit is too large, it will cool the room quickly, but only remove some of the humidity. This leaves the room with a damp, clammy feeling. A properly sized unit will remove humidity effectively as it cools."
see http://www.energystar.gov/index.cfm?c=roomac.pr_properly_sized

Argh: buying an, not buying and...

I just bought a 10,000 BTU wall-through ac since my small studio has a cut-out designed for one, and sliding windows.

You can google guides on matching BTUs to room size. Larger is not better, but I suspect most people trying to save money end up with a too-small AC.

My apt has a 220v plug next to the wall-through. I've been told one should always go with a 200v if that plug is available, since it's designed for the load. 220v has two horizontal slots.

FYI, some people believe that leaving the AC on when gone draws less power than turning it on or off. This is not exactly true. Newer ACs usually have thermostats and an auto setting. Set the thermostat to 78 or higher when you're out.

Some newer ACs now use a different refrigerant that is more environmentally friendly. There's no reason an AC shouldn't have an EnergyStar rating at this point.

Oops, 220v not 200v. But DO check the plug before you purchase, especially on larger units.