Summer 2017 is here, and that means one thing for millions of people: air conditioning. And while we may take AC for granted, it’s generally an expensive luxury.
If you’re shopping for a new air conditioner, you’ll notice quite a few different sizes and models. Here’s a quick primer on staying cool and keeping your wallet from overheating while picking out an AC unit.
Know how many BTUs you need based on room area
Chances are you already know that BTU stands for British thermal unit, and the more BTUs an air conditioner cranks out, the stronger its cooling power. But here’s the problem: Most American consumers aren’t sure how to translate BTUs into the square footage of a room. (No disrespect to the Brits, but maybe we need an American thermal unit, where 1 AMU corresponds to 1 square foot?)
Lobbying for the AMU aside, you don’t have to guess how much BTU power you’ll need to cool your space. Instead, check out this (similar) handy Energy Star website. It simply correlates the area you want to cool into BTUs per hour.
So for example, an air conditioner with a rating of 8,000 BTUs can cool a room that’s 300 to 350 sq. ft., or one that measures about 18 ft. x 18 ft. Of course, you still have to measure your room, but we trust you can work a tape measure and apply this formula: Area equals length times width.
For irregularly sized rooms, you can always estimate by breaking down the room into smaller geometric shapes and calculating the size of those.
Most people think bigger is always better, but it’s not always so with AC. According to the Energy Star folks, “Air conditioners remove both heat and humidity from the air. If the unit is too large, it will cool the room, before it has a chance to remove the humidity. The result will be a room that’s not very comfortable to spend time in,” and “That cool moist air will make the room feel damp and clammy.”
Damp and clammy isn’t much better than sweltering.
Use a ceiling fan, too
It’s one thing to run an air conditioner in your room. But combine its power with a simple ceiling fan, and you can have the best of both worlds. Often costing less than a penny an hour to run, ceiling fans have an immediate impact on your domestic comfort once you buy and install them.
They generally start at about $40 apiece. The nice thing about a ceiling fan is it can make you feel anywhere from 3 to 8 degrees cooler.
Calculate your yearly costs before you buy
When you buy any air conditioner these days, it should come with one of those bright yellow Energy Guide stickers on the box that tells you exactly how much the unit will cost to run. Take this into account because it’s part of your total cost for both buying and operating the unit.
Get an Energy Star model
If your unit is more than nine years old, seriously consider replacing it. According to the U.S. Environmental Protection Agency, room air conditioners that are Energy Star certified are typically 13 percent more energy-efficient than standard models. Depending on how long you hold onto that new unit, you could save $99 or more over its lifetime in energy costs alone — a de facto rebate just for upgrading to an Energy Star model.
The key number to look for is the energy efficiency ratio, or EER: The higher the EER, the more efficient the unit. So if you replace an old EER 5 unit with a new EER 10 unit, you can cut your cooling costs in half.
You should also look for the “Energy Star” and “Energy Guide” labels when purchasing a window unit. An energy-efficient unit will cycle the compressor on and off so it doesn’t operate continuously. And Energy Star central air units have higher EER ratings and use 8 percent less energy when compared to conventional new models.
Consider central air
If you’re thinking about upgrading to central air, it’s easy to beat yourself up for being an energy hog or to get intimidated by the sticker price. Yes, it’s true that central units will use a lot more power than, say, a single window unit on each floor of a 2-story dwelling. But if you have more than two rooms to cool, then your best bet is to go with a central unit, which also provides long-term resale value for a home.
Well-designed central systems also win out in terms of being able to filter the air for allergens and pollutants, and for controlling humidity.
Again, keep in mind that window units aren’t necessarily more energy efficient than central air units. A window unit that’s too small to cool a room may run continuously, wasting energy. When shopping for a central air conditioning system, make sure the SEER number (seasonal energy efficiency ratio) is 15 or better. A less efficient system will cost you more to run.
Get a programmable thermostat
It’s easy to think that buying a new air conditioner or two will solve all of your summer cooling problems. But your AC could use a little help. With central units, for example, a programmable timer or thermostat can save you about $180 every year in energy costs by regulating the temperature when you’re out of the house, and by turning on only when you return home.
Clean your air filters regularly
With window units, air filters get dirty, and fast. Clean your AC filter at least every month because a dirty filter makes your AC work harder and use more electricity. Regardless of the type or age of the unit, you should change your filters after every 90 days of use.
Block sunlight with drapes
What’s more, you’ll use less energy to cool down a room by keeping direct sunlight out during the day. Sunlight can raise the room temperature by 10 to 20 degrees. The less heat that gets into your home, the less you have to pay to remove it. It just so happens that drapes block sunlight and heat better than blinds.
Do some careful deal shopping for your AC
DealNews keeps an ever-updated list of air conditioning deals for you to peruse and compare. Of course, this time of year, AC sales are as plentiful as backyard barbecues.
The worst thing to do is feel a heat wave hit you in the face, rush to the first store you can find and buy the first unit you see. Do some comparison shopping, checking out multiple units for price, efficiency, reliability and features.
The few minutes you spend comparing notes and using your shopping smarts will do more than show off how cool you are. It’ll help you make a prudent choice that will keep your living space comfy all summer long, and for many summers to come.