Buying a new air conditioner isn't quite like buying, say, a new bottle of shampoo. We buy shampoo often enough that we know what we need, what we like, and we just get that. But an air conditioner is a big purchase, one we rarely make, and it's important to keep in mind a few things to make sure you're getting the right one. Air conditioners can get expensive, so you need to make the right purchase the first time.
How much power do I need? How many BTUs?
This is the most important question. Everything else flows from this. Air conditioners are rated in terms of BTUs, or British Thermal Units. The important thing is that a higher number means a more powerful unit, and most homes don't need a big air conditioner. So let's take that into consideration.
Most living rooms are about 250 square feet, so if you're buying a unit just to cool your living room, you probably don't need more than 7000 BTUs. That's a small window unit right there. So, going from there, your BTU needs scale up with your home size. Find out which is right for you by using the BTU Calculator.
How can you use this information? Easily! With this knowledge, you can plan out your AC air home cooling system with great accuracy. If you own a small apartment, you can get by with no more than two small window units. If you own a large home, it'd probably be more efficient to work out a more comprehensive central cooling system that's capable of regulating the temperature of your entire home with one unit. Whatever your needs, you can effectively plot out your cooling solution with the BTU Calculator.
Where will I be installing it?
Different people want different things out of their air conditioning systems, which is often dictated by their living spaces. The home cooling options for a studio loft in Midtown Manhattan are quite different than those for a single-family suburban home in Poughkeepsie, and it's important to be aware of your choices so you can pick responsibly.
Apartment rentals that aren't served by building-wide central air conditioning are limited to window units, that means an entire living space can be served with the simple seasonal installation of these flexible units. Urban, suburban, or rural homes have considerably more options, including units which require a more-involved one-time installation.
Both mini-split and through-the-wall units require installation through exterior walls rather than windows. That means that part of the wall will need to be knocked out for the installation of the unit or the necessary ducts. This lets you both avoid yearly installations and keep your window clear, while also offering superior insulation than a standard window unit. Mini-split units offer a special advantage in that as many as four rooms can be cooled off of a single outdoor air conditioning unit.
Do I want a unit that includes a heating system?
Air conditioner units can do more than just cool your home, and some of them even offer heating potential.
What? An air conditioner can provide heating and cooling for my home, too?
Surprisingly, yes! There are many different AC units that offer distinct forms of home heating solutions in addition to home cooling.
Heat pumps, one of the basic components of air cooling systems, can be used in reverse to provide heat. As long as temperatures don't dip too far below forty degrees Fahrenheit, a heat pump can extract heat from outside air and use it to provide warm air for your home. Heat pump systems are great for moderate, temperate climates that don't vary too wildly. Electric heat systems utilize traditional heating technology, using a standard electric element to provide the heat, and the air conditioner’s own fan to distribute it through the room.
Neither an electric heat system nor a heat pump are intended as a stand-alone heating solution, but as a supplement to more common home heating systems, such as radiators or central air, so you shouldn't lean on it to provide that.
Heating capacity is also measured in BTUs.
How loud is an air conditioner?
Most air conditioners run pretty quietly, so don't stress too much about a unit being terribly loud. Most AC window or through-the-wall units, which tend to be the quietest air conditioners, run about 25 decibels, which is quite literally whisper-quiet, while portable air conditioning units can be as loud as 55 decibels, which is approximately as loud as a dishwasher or a normal speaking voice. For comparison, a telephone dial tone is 80 decibels and a jackhammer is 95 decibels, so we aren't talking about anything particularly loud.
Do I want individual room climate control?
The most efficient and flexible system out there for large-scale home cooling is the mini split or ductless air conditioning system. While most of us here in North America tend to rely on central air conditioning if we want a comprehensive home cooling solution, central air systems are pretty energy inefficient and only allow for a single temperature to be maintained throughout the home. That means that if there's any disagreement on temperature, everyone ends up unhappy.
Mini splits offer individual room temperature control for as many as four rooms off a single unit. This means that you get unparalleled flexibility and energy efficiency at minimal cost. These units are widespread in Europe, where they've become the standard over our central air conditioning system, which requires extensive ductwork and takes a long time to begin cooling the home.
Individual room climate control can also be accomplished with individual window AC or wall air conditioning units in each room, but this is profoundly more energy-intensive. Window air conditioning units would be an ideal solution for apartment or home rentals without special permissions to install a mini-split system.
What climate do I live in?
Different climates have different air conditioning requirements. Most moderate climates, such as the Mid-Atlantic, parts of the Pacific Coast, and anywhere else that doesn't feature crazy climate extreme are easily served by most standard air conditioners.
But if you live in, say, the Florida Panhandle, in the marshes of South Carolina, or anywhere else that's notorious for high and heavy humidity, you're going to want to pay attention to an air conditioner's dehumidification power, as that will probably have as much an effect on how comfortable you are as the base temperature, if not more so. Strong dehumidification is usually present in most top-flight systems, but for other systems, it may be necessary to purchases a standalone dehumidifier. You can reduce the need for dehumidification by keeping your unit to "fan off," which will prevent it from blowing in the humidity it's been working so hard to fight.
Meanwhile, people in Arizona, New Mexico, Nevada, parts of Utah, or anywhere else with a dry, hot climate will want to make sure they're getting the best EER, or energy efficiency rating, they can find, because they're going to be running these units hard for much longer periods of time than someone in Brooklyn or Lansing, so they'll want the most efficient air conditioner they can find.
Can I power this air conditioner safely?
Different amperages make use of different types of plugs and outlets, and it's important when you make your purchase to make sure you're properly equipped to power your new air conditioner. Below is a handy chart of different outlet styles. Most air conditioners will use a 5-15P, 6-15P, 6-20P, or 6-30P.
Click below on the 5-15P, 6-15P, 6-20P, or 6-30P outlets for units that use them:
Voltage for air conditioning units needs to be either 115 or 230/208 volts.
Air conditioners can be very intensive in terms of eating up electric current, so make sure you're giving your air conditioner a dedicated line, or a wall outlet with only a single receptacle. If you can't provide a dedicated line, you need a unit with a maximum of 115 Volts and 7.7 Amperes in order to prevent blowing a fuse.