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# How to stay cool and save on air conditioning

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Beatriz Costa-Lima/AP/File

(Read caption) A worker fixes a home air-conditioning unit in Tempe, Ariz. When temperatures heat up, make sure you know how to cool down and stay within budget.

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Summer 2016 is off to a sultry start, and that means one thing for millions of people: air conditioning. And while we may take A/C for granted, it's generally an expensive luxury. Americans spend more than \$11 billion a year on electricity to cool their homes with air conditioning. That accounts for at least 6% of all energy used in some homes.

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 A/C 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?)

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.

#### 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. 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 a piece. The nice thing about a ceiling fan is it can make you feel anywhere from 3 to 8 degrees cooler.

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, as it's part of your total cost for both buying and operating the unit. Most folks think bigger is always better, but not so.

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 quickly, but only remove some of the humidity. This leaves the room with a damp, clammy feeling. A properly sized unit will remove humidity effectively as it cools." Damp and clammy isn't much better than sweltering.

#### Get an Energy Star Model

If your unit is more than 10 years old, seriously consider replacing it. According to U.S. Department of Energy estimates, you'll use about 10% less energy with a new Energy Star appliance than one without that designation. Depending on how long you hold onto that new unit, you could save \$60 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 Rating (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'll 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 are 14% more efficient on average than standard models.

Energy Star central air units are 14% more efficient on average than standard 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 is 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 13 or better (14 in warmer climates). 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 Out Your Air Filters Regularly

With window units, air filters get dirty, and fast. Clean your AC filter at least every month, as 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 cooling 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 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 A/C

DealNews keeps an ever-updated list of air conditioning deals for you to peruse and compare. For instance, BJ's Wholesale Club offers this LG 10,000 BTU Window Air Conditioner (\$249.99 with free shipping, a low by \$49). Of course, this time of year, A/C 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.