Buying Air-Conditioning

Memorial Day has passed and, like clockwork, it has become hot and borderline uncomfortable in New York. If summer hasn’t hit your neck of the woods yet, it probably will soon. So how do you avoid annoying situations such as feeling dehydrated and not being able to wear the boxers you slept in? Hook up some air-conditioning, of course.

If you are lucky enough to live in a house or apartment with AC, then your only real concern should be budgeting your usage so that you don’t rack up an enormous energy bill. Blasting it for 12 hours just so that you can experience that feeling of stepping into an ice box at the end of the work day is simply egregious.

For those of us living in a leased spot sans-AC, spending thousands of dollars installing a central cooling system is clearly not in the cards. If you can't find a gaggle of pretty young things to swarm you with hand fans as you slumber, you're probably going to want to look into a window air-conditioning unit. Here's what you need to know before making a purchase.

Measure the room AND the window

As we’ve discussed before with mattresses and TVs, the lion’s share of the decision-making process for a copping an AC unit comes down to taking some simple measurements. Measure the width and length of the room and multiply to figure out the square footage of the space you want to cool. This will be essential in determining the strength that you require (see below). If two or more rooms are open plan, you’ll want to include the whole space in your measurement. However, the cool air will not go around corners, so if you put the unit in the living room don’t expect it to make much of a difference in your bedroom down the hall (or even next to the window where you install the AC unit). You also need to measure the window to make sure the unit will actually fit—all models will tell you the maximum and minimum dimensions. Ignoring these preliminary measurements could literally be disastrous.

Mind your Btus (and EER)

There’s a magic little number in the world of air-conditioning and it’s measured in Btus (British Thermal Units), the international measure of energy. There is some “science” behind this but suffice to say that the Btu is measurement that determines how efficiently the unit will cool a room. A higher Btu rating means the unit will be bigger, more expensive, and more powerful. Once you’ve measured the space, use this chart to determine your Btu requirements. (Alternatively, you can get a good ballpark figure by just multiplying the square footage by 35.) As mentioned before, base your calculation on the immediate room being cooled, not your whole apartment or a group of rooms connected by doors. Furthermore, don’t make the common mistake of assuming that you should just opt for more Btus than you need. It’s all about efficiency, not sheer power—going too high will result in an uncomfortably cold room.

Once you’ve determined the Btu you’re pretty much ready to hit the marketplace, but it’s also advisable to have a simple understanding of EER (Energy Efficiency Ratio). Divide the Btu by the number of watts used and, bob’s your uncle, you’ve got the EER. It’s going to be somewhere between 8.5 and 11; the higher the EER, the more the unit will cost. There are basically only three reasons you would want to go north of a 10: (1) You want to use your AC unit for several years and plan to use it a lot (i.e., you live in a place that’s hot a decent amount of the year and you spend a lot of time at home), (2) You live in a place that is mad hot, or (3) You are proactive enough to figure out how much you’ll save on your energy bill by shelling out for a more efficient unit.

For a good breakdown of AC-related terms, check out Lowes’ Air Conditioner Buying Guide.

Decide what type of unit you want (and determine your price range)

More than likely, you’re going to get a window unit. But just so you’re aware of the options and price ranges, SoYouWanna has a good breakdown of the three main types of air-conditioning and their respective price ranges. Here’s a summary:

1. Window unit: The standard kind you stick in any normal double-hung window. Should have multiple settings. These are what this survival guide is all about. Approx. $250-800.
2. Built-in window The fancier, more expensive kind that can go in the window or right into the wall. Usually has more settings, offers heat as well as AC, and uses more energy. Approx. $500-800.
3. Split-system Has an outside air-compressor unit that cuts down on noise. Maybe worth looking into if you're putting it in your bedroom and you're a sensitive sleeper. Approx. $300-1000.

In reality, you could find a window unit for anywhere from $100 to well over $1000. If you have a strict budget, go for what you can afford. If you’re flexible, use the discussion above about Btu and EER (the main determinants of price), as well as other “bells and whistles,” to decide how much you should spend.