Air conditioning season is here! We’ve got the scoop on choosing a unit that best fits your needs. And check out our annual air conditioner picks post where we find the top rated models for the year.
The most common way to determine which air conditioner size you need is to calculate the square footage you want to cool then choose the air conditioner with the recommended BTU. Most home window units typically run anywhere from 5,000 to 15,000 BTUs and can cool from 150 to over 500 square feet. They’ll work in a regular 115 volt outlet (one unit per outlet!). If you want an air conditioner with more BTU power, you’ll need a 230 volt circuit. But keep in mind – the bigger they are, the heavier they are. Smaller home air conditioners weigh in at around 40 pounds while 15K BTU units can be over 60 pounds.
While BTU is a good size guide, where you place the unit can affect the coverage. Hot southern and western exposure will make your air conditioner work harder – even more so if there’s no shade. If that’s the spot it needs to go, however, consider plantings or even a window awning to provide some cover. But if you don’t have those options, half the square footage the air conditioner is supposed to cover.
Within the room, if you want spillover to other areas, you’ll want to place it in a window directly opposite or very near the doorway. But don’t expect the same amount of cooling in the areas outside of the room. It’s actually better to choose multiple smaller units to cover larger areas – including a single, large room. Multiple units keep the cool air moving around the room reducing warm spots.
No Window, No Problem
No windows or window units not allowed? You (or a contractor) can cut out and mount a unit through an outside wall. Another option, portable air conditioners, need a place for water to drain. That could be a window, utility sink or floor drain.
Energy efficiency is another consideration. Air conditioners use EER ratings (energy efficiency ratio) to determine effectiveness. A rating of 10 or more is a highly efficient unit. Even modestly priced air conditioners have ratings this high. The next best option is an Energy Star rated unit which must have an EER of around 9.
If you can afford it, choose units with energy saver options. Those that shut down the entire unit rather than just the compressor are big energy savers. Timers and programmable settings/thermostats will also help you save. You can even find wi-fi enabled units that let you remotely turn your air conditioner on and off.
Don’t forget to measure your windows! Most units have slide out panels on each side to adjust to various window widths. You also may need to screw the panels into the molding as well as the window frame so make sure you can do that. The window opening also needs to accommodate the unit’s height. In cases where you have narrow sills, get an air conditioner shelf for the unit to sit on.
Proper installation and maintenance are both critical. A good fit without air holes and sufficient insulation along with regular cleaning of coils and filters all help you get the most from your air conditioner. If you intend to leave the unit in year-round, skip the cover. They actually trap moisture and debris. Better to check and clean the exterior each season.
While some of us don’t care and might even find the sound of the fan soothing, the rest of us are driven crazy. No air conditioner is truly quiet, but some are quieter than others. Read the specs to find out what the decibel level is (the lower, the quieter) but on average, it’s around 50 – a little quieter than normal conversation. The quality of the sound can make a difference, too. Some brands emit a loud hum rather than the familiar vibrating fan/compressor but it’s a matter of taste as to which you prefer. Noise, however, is the price you pay to stay cool. Just don’t try to muffle the unit with pillows or blankets. Use ear plugs instead.
Personal Air Conditioners
What about those personal air conditioners you see advertised on TV? Called “swamp” or evaporative coolers, they’re essentially cool air humidifiers that push mist through the room with a small fan. These work best in dry climates where a little extra humidity isn’t a problem. While they won’t cover large areas – most are sold as “personal” devices – they can provide 5-10 degrees of relief for those sitting nearby. But skip them if you live in naturally humid areas. The last thing you want to do is add even more humidity to already sticky air.