Air conditioners are not one-size-fits-all cooling solutions. They come in different varieties, each suited to different environments. There are four main types of air conditioners: portable air conditioners, window air conditioners, split air conditioners, and central air conditioners.
Portable Air Conditioners
Portable air conditioners are small, mobile units that can be moved from room to room. They’re cheaper and use less electricity than fixed units. They vent air through a hose attachment that is connected to your window, commonly referred to as a window kit.
Besides the hose, portable air conditioners require no additional installation. They’re ready to go right out of the box.
The downside is that their cooling area. It’s generally much smaller than the other units on the list, which means they’re not effective unless they’re used in small, enclosed spaces.
Window Air Conditioners
Window air conditioners are designed to fit in your window and cool a single room. Because they vent hot air directly outside, instead of through a hose, they heat they generate isn’t re-released back into the room, which means they can cool faster than a portable AC unit. It also makes them great humidifiers.
Like a portable air conditioners, window air conditioners circulate interior air, but vent they vent it directly outside, so there’s no need for draining or additional maintenance. Installation is easy. Most units can be installed without professional help.
Split Air Conditioners
Split air conditioners are hybrids between single room and central AC systems. Like central AC, they use an outdoor compressor-condenser unit to generate cold air and vents it through a small, indoor wall unit connected directly to the compressor through a tubing line drilled straight through the wall.
Split air conditioners are normally used to cool only one or two rooms, but because their compressor is located outside, they’re much quieter and less obtrusive than portable or window air conditioners.
Central Air Conditioners
Central air conditioners are powerful cooling systems designed to cool entire buildings. They use large, outdoor condenser units that pump cold air in through a system of air ducts.
Like split ACs, they’re quiet, unobtrusive, and, because they lower the temperature of the entire house, rather than a single room, they’re generally more efficient than portable or window units. Though their installation and operating costs are considerable higher.
What Type is Right For You?
The type of air conditioner you need depends on the area you need to cool. You need to account not only for the size of the room, but also what kind of activities take place there.
The size of the unit you select is the most important aspect above all other features. Why is this so? Because the size (in terms of tons or BTU output, not physical size) determines:
- The overall cooling capability of the unit.
- How often the compressor will turn on & off.
- Factors heavily into the energy efficiency & operating cost.
- Maintenance costs over the life of the unit.
Strangely enough, the most common problem encountered in existing construction is over sized units.
In studies performed by utility companies on the west coast, one found that slightly over 1/2 of the home air conditioners checked were a ton (12,000 Btu/h) or more oversized and another company found the same in 1/3 of the home air conditioners they checked.
Why is this so? Because the correct method of calculating the optimum size of the unit needed is rather complicated and most contractor use shortcuts to save time. Either that, or they just don’t know how to do it properly.
The MANUAL J calculation is the universally accepted standard. It was jointly developed by the Air Conditioning Contractors of America (ACCA) and the Air-Conditioning and Refrigeration Institute (ARI). It is a lengthy publication, and rightfully so since it factors in all of the variables that must be considered to properly size home air conditioners.
Consumer Reports recommends 20 BTUs per square foot of space you want to cool down. Here’s a convenient list for figuring how much A/C power you need based on the room’s square footage:
- 150 – 250 sq. feet: 6,000 BTUs
- 250 – 300 sq. feet: 7,000 BTUs
- 300 – 350 sq. feet: 8,000 BTUs
- 350 – 400 sq. feet: 9,000 BTUs
- 400 – 450 sq. feet: 10,000 BTUs
- 450 – 550 sq. feet: 12,000 BTUs
- 550 – 700 sq. feet: 14,000 BTUs
- 700 – 1,000 sq. feet: 18,000 BTUs
- 1,000 – 1,200 sq. feet: 21,000 BTUs
- 1,200 – 1,400 sq. feet: 23,000 BTUs
- 1,400 – 1,500 sq. feet: 23,000 BTUs
- 1,500 – 2,000 sq. feet: 30,000 BTUs
- 2,000– 2,500 sq. feet: 34,000 BTUs
We’ve distilled our recommendations down to a single chart, to the right. It contains cooling suggestions for every room in your house.
Low-Priced A/C Units
- Emerson Quiet Kool 5,000 BTU Window Air Conditioner with Remote Control
Mid-Priced A/C Units
- LG Energy Star 6,000 BTU Window Air Conditioner
High-Priced A/C Units
- Frigidaire 10,000 BTU Cool Connect Smart Window Air Conditioner with WiFi Control
- Friedrich Commercial Kuhl Window 5,800 BTU Air Conditioner
When selecting the type of air conditioner do you need, a complete analysis should be performed. This will provide the HVAC contractor with proper numbers that will help them recommend the right AC for your home.