How to Save on Home Air Conditioning & Energy Costs in the Summer

Summertime has a lot going for it: pool parties, backyard cookouts, baseball games, and Fourth of July fireworks. However, the one thing that’s not so great about summer is the heat. On a blazing July day with the temperature in the 90s (and, if you live on the East Coast like I do, soaking humidity on top of that), it can be tempting to stay indoors all day with the air conditioner cranked up.

Unfortunately, air-conditioned comfort comes with a high price tag. According to ENERGY STAR, nearly half of the average household’s summertime electric bill is spent on cooling the home. And according to the Energy Information Administration, the average household’s energy bill for the three months of the summer comes to more than $400, so that adds up to more than $200 a year spent on air conditioning.

However, there are ways to reduce that cost. Home energy expert Michael Bluejay explains that a central AC system is one of the biggest energy hogs in your home, using about 3,500 watts – or 3.5 kilowatt-hours for each hour it’s used. A window air conditioner, by contrast, can cool one room with only 900 watts, and a floor fan on high speed can cool you off with just 100 watts. So the less you run your central AC in the summer, the more you can shrink your utility bill – and your carbon footprint as well.

Keep the Heat Out

There’s not much you can do about how hot it gets outside, but there are plenty of things you can do to keep the heat out of your home. Improving your insulation and sealing up leaks helps keep hot air out and cool air in. You can also stop the sun from overheating your home with careful choices about window treatments, roofing, paint, and landscaping.

Here are several methods to investigate:

1. Insulate and Seal

It’s basic thermodynamics: When it’s hot in one spot and cool in another area close by, heat naturally moves toward the cooler area. You can’t completely stop this temperature shift, but you can slow it down by walling off the cooler area with a material that doesn’t transfer heat easily. So when you add insulation to your home, you’re basically slowing down the rate at which heat can pass through the walls, keeping cool air in and hot air out (or vice versa in the wintertime).

The level of insulation in your home is expressed as an “R-value,” which is a measure of how much heat can transfer across a given area in a certain amount of time. The higher a material’s R-value, the more insulation it provides. So, for instance, a typical exterior wall has an R-value of around R-19, while a double-pane window has an R-value of around R-2. Simply put, that means it’s much easier for heat to pass through a thin glass window than through a thick concrete wall.

To improve your home’s insulation, you can:

  • Keep Windows Shut. Keep your windows closed during the day, when it’s hotter outside than it is inside. Even if they provide only a little bit of insulation, a little is better than none. In the evening, when it has cooled down outside, open the windows to let in cooler air.
  • Upgrade Your Windows. According to the Department of Energy (DOE), your windows account for anywhere from 10% to 25% of the heat your home gains and loses – and older windows tend to fall toward the high end of this range. Many old windows have just one pane of glass, while newer windows have two or three panes with an insulating layer of gas sandwiched in between. Modern energy-efficient windows also have better-insulated frames, so less heat is lost around the edges of the glass. However, replacing windows is a costly job – between $450 and $650 per window, according to Angie’s List. So if your current windows are reasonably new and in good shape, replacing them probably isn’t worth the cost.
  • Add Storm Windows. A cheaper way to get the benefits of a multi-pane window is to install temporary storm windows. These are rigid panes of glass or plastic that you can put up either outside or inside your existing windows, trapping a layer of heat-blocking air in between. The DOE estimates that new storm windows cost between $60 and $200 per window and can save you anywhere from 12% to 33% on your annual heating and cooling bills. Installing them is a simple DIY job that should take approximately 30 minutes or less.
  • Insulate Your Attic. Many houses in this country – especially older ones – have less insulation than they need. This map on the ENERGY STAR website shows how much insulation you should have in different parts of your house, based on where you live. Insulation is especially important in your attic, which the blazing summer sun can heat up to oven-like temperatures. Adding insulation to the attic keeps all that stored heat from spreading into your living space. According to Michael Bluejay, this can save you as much as 40% on your summer cooling bill. The Family Handyman says you can add blown-in cellulose insulation to your attic as a DIY job for about $500. To get the most benefit out of your added insulation, take care to seal up any holes and air leaks in the attic before you add it.
  • Install a Radiant Barrier. You can insulate your attic still more by adding a radiant barrier – a coating of reflective material across the underside of the roof that blocks out radiant heat from the sun. Radiant barriers are usually made from aluminum foil applied to a backing of paper, cardboard, plastic, or wood. If you install it yourself, a radiant barrier costs around $250 for a 1,500-square-foot attic. The DOE reports that in a warm, sunny climate, adding a radiant barrier to your attic can reduce your overall cooling costs by 5% to 10%.
  • Seal Doors and Windows. Even the best-insulated walls won’t keep your house cool if there are big gaps around your doors and windows that allow cool air to escape. Fortunately, it’s easy to seal these air leaks with caulk or weather-stripping. The DOE says caulking is an easy DIY job that takes just a couple of hours, costs less than $30, and can cut your energy use by 5% to 10%. Weather-stripping around windows is even cheaper and easier, requiring just one hour and $5 to $10.

2. Shade Your Windows

When the sun comes beaming in through your windows, it heats up your house just like a greenhouse. According to Michael Bluejay, direct sunlight can increase the temperature of a room by 10 to 20 degrees Fahrenheit. This effect is known as “solar heat gain.”

However, any type of window treatment you use for privacy – including curtains, roll-up shades, Venetian blinds, and shutters – can also reduce solar heat gain. All you have to do is close the curtains or blinds on the windows that face toward the sun. If you’re out of the house during the day, you can just darken the house completely until you come home. If you’re at home, you can close the curtains on east-facing windows in the morning, then open those in the afternoon and close the ones on west-facing windows.

The DOE says curtains stay cooler than other window treatments because the movement of their folds and pleats disperses hot air. Curtains with white linings, which reflect radiation, are the best of all. According to the DOE, “medium-colored draperies with white-plastic backings can reduce heat gains by 33%.” To get the most benefit from curtains, hang them close to the windows and let them fall all the way to the window sill to block the light fully.

Other ways to block solar heat gain include:

  • Exterior Shutters and Shades. Shutters on the outside of the windows can block out sunlight before it even hits the glass. However, this only works with real shutters that open and close, not the decorative kind that are fixed in place. If your house doesn’t have shutters, you can hang roll-up shades made of bamboo or vinyl strips outside the windows on the sunniest side of your house. You can roll these up and down by hand with a pull cord. Close them in the morning to block out sunlight, and open them in the evening to let in cool breezes. Outdoor shades sell for $25 to $120 apiece at Home Depot.
  • Awnings. In hot climates, many houses have roof overhangs, which extend to the edge of the roof past the outside walls of the house. Adding an overhang to an existing house is difficult, but you can easily shade your windows by adding awnings. The DOE says awnings can cut solar heat gain by up to 65% on south-facing windows and 77% on west-facing ones. Awnings can be removed or retracted in the winter to let sunlight in. The DOE recommends awnings made of a light-colored, opaque, tightly woven synthetic fabric that’s water-repellent and mildew-resistant. These cost between $100 and $650 per window, based on prices at Home Depot.
  • Solar Screens. Most windows have screen inserts to block out insects, but they don’t provide much shade. However, if you replace your standard mesh screens with a denser mesh called solar screening, they can block up to 70% of the heat from incoming sunlight. Solar screening is sold at home improvement stores and comes in varying densities. It’s best to choose one that doesn’t block out too much light, since this could lead you to use more electric lighting and heat up your house from the inside. Solar screens are particularly effective on east-facing and west-facing windows, which get direct sunlight in the morning and evening. You can make your own by mounting solar screening in a frame that fits over the outside of your window, covering the entire pane. The materials cost about $25 per window, according to Home Depot.
  • Window Film. Instead of installing screens over the outside of your windows, you can line them on the inside with a film that can block up to 60% of the sun’s heat. These films are best for warm climates, since they also block out solar heat in the wintertime when it’s useful. Window films come in two kinds: tinted films, which change the color of the sunlight entering the room, and reflective films, which have a mirror-like finish. The reflective films are generally more effective, but they can also obscure your view and cause reflections inside the room. The DOE recommends installing film on east-facing and west-facing windows, which absorb most sunlight in the summer. North-facing windows don’t gain much heat from sunlight, and south-facing windows should be left bare to get the benefits of solar heat gain in the winter. Reflective window film costs around $10 per square foot. Like solar screens, window film should be chosen with care so it doesn’t block out too much light.

awning on a house shades back porch

3. Absorb Less Heat

Your windows aren’t the only part of your house that can absorb heat from the sun. You can prevent solar heat gain throughout the house with the following:

  • Light-Colored Paint. As you may know, dark surfaces heat up a lot more in the sun than light ones. Therefore, painting your house a lighter color can help reduce the amount of heat it absorbs from the sun, reducing your cooling costs. The downside is that a lighter-colored house also absorbs less warming sunlight in the wintertime. However, according to Bluejay, the summer savings outweigh the winter losses in all but the coldest climates. Having your house professionally repainted costs between $1,500 and $3,000. However, you can do it yourself with $400 to $600 worth of paint and other materials.
  • A Cool Roof. The next time you need to replace your roof, consider a “cool roof” – one made with special reflective materials or coatings to block out the sun’s rays. According to the DOE, cool roofs stay about 50 degrees Fahrenheit cooler in the summer sun than standard dark-colored roofs, and they cost about the same. Because cool roofs also absorb less heat in wintertime, they’re most useful in warm climates where people spend more on summer cooling than they do on winter heating. The Oak Ridge National Laboratory offers a Roof Savings Calculator that can help you figure out whether a cool roof is cost-effective for your house.
  • Shade Trees. Trees cool the area around them in two ways: by providing shade, and by moving and releasing water vapor through their leaves. According to the DOE, the air temperature directly under a tree can be as much as 25 degrees cooler than the air directly above a nearby road. Deciduous trees – the kind that lose their leaves in the fall – can provide summer shade while still letting the sun shine through their bare branches in wintertime. Tall trees on the south side of your home provide the best shade for the roof, while trees with branches closer to the ground are useful on the west side for blocking out the lower afternoon sun. The DOE says a six- to eight-foot-tall deciduous tree can provide shade for your windows as soon as it’s planted, and within 5 to 10 years it can begin shading the roof. According to Angie’s List, a six-foot tree from a nursery typically costs between $50 and $200 if you plant it yourself. However, hiring a professional landscaper to deliver and plant it adds $100 to $500 to the cost.
  • Other Shade Plants. Smaller plants, such as shrubs and vines, can be strategically placed to shade specific parts of your home and yard. For instance, you can plant a hedge to shade your sidewalk or build a trellis for climbing vines to shade a patio. Vines can also help shade your home’s exterior walls, and large potted plants such as bamboo can be placed in front of sunny windows. This Old House explains how to build a shade arbor for your patio for $800 to $2,000 worth of materials, and there are many types of climbing plants you can grow to cover it from a $2 packet of seeds.
  • Shade Cloth. If you have an outdoor living area, such as a deck, patio, or playground, you can keep it cool by adding a canopy of shade cloth. This loosely woven synthetic material is used in greenhouses to shield plants from direct sunlight, but it can do just as good a job of providing shade in your yard. Rolls of shade cloth sold at Home Depot cost around $0.30 per square foot. You can attach the material to an existing pergola or any other sort of wood or metal frame.

Add Less Heat Inside

Blocking out the heat doesn’t do much good if you just turn around and create more heat indoors. Sources of indoor heat include:

  • Cooking. When you heat up your kitchen by running the stove or oven, your air conditioning has to work overtime to remove that heat. So during the summer months, rely on smaller appliances that create less heat, such as a microwave, toaster oven, or slow cooker. You can also move the heat of cooking outdoors by using a barbecue grill. And if you do need to use the stove, make sure to run the exhaust fan to remove as much of the hot air as possible.
  • Appliances. Other appliances, such as dishwashers and clothes dryers, can also heat up your home from the inside. Running these appliances at night, when the air is cooler, reduces the burden on your air conditioner. You can also reduce the heat your dishwasher puts out by skipping the dry cycle and letting your dishes air-dry. And if it’s sunny out, you can skip the clothes dryer completely and use a clothesline to dry your laundry.
  • Showers. Even in the summertime, some people prefer to start the day with a hot shower. If you’re one of them, make sure to turn on the bathroom fan to vent all that steamy air, instead of letting the heat and humidity build up in your home.
  • Electronics. Your computer, stereo, and TV all generate heat that bumps up the indoor temperature. Even when they’re not turned on, these gadgets continue to draw a trickle of heat-producing current. So to keep your room as cool as possible, unplug these devices when you’re not using them, or plug them into a power strip you can shut off.
  • Lighting. If you’re still using old-fashioned incandescent light bulbs, more than 80% of the electricity they use is being turned into heat rather than light. It’s long past time to swap out those inefficient bulbs for new ones that stay cooler, such as compact fluorescent bulbs or LEDs. You’ll spend less on electricity and keep your house cooler at the same time. During the daytime, you can also make use of daylight without adding too much heat by opening the blinds on windows that aren’t in direct sun.

Aside from reducing your cooling needs, most of these heat-reducing steps also save energy directly, reducing your electric bill still more. And, as a bonus, they’re good for the environment as well.

man on a couch using a remote control for air conditioner

Cool Yourself Without Air Conditioning

On the hottest days, it’s tough to block out enough heat to keep the house comfortable. However, that doesn’t mean turning on the air conditioner is your only alternative to sweltering. There are many other ways to cool yourself down that use a lot less energy and a lot less money:

  • Dress for the Weather. Summer is no time to sit around in jeans and a sweatshirt. Switching to lighter clothes, such as shorts and tank tops, is much more comfortable. The more skin you’re showing, the easier it is for your sweat to evaporate and keep you cool.
  • Use Fans. A fan doesn’t actually cool your room, it cools you directly by blowing away the cushion of warm air that accumulates around your body. This doesn’t help much in extreme heat (over 95 degrees Fahrenheit) because there’s no cooler air to replace it. But at lower indoor temperatures, a fan can make you feel several degrees cooler. You can buy a basic desk fan for as little as $15 and a more powerful tower fan for around $60. Even on its highest setting, a tower fan uses less than 100 watts of energy – far fewer than the 900 watts a typical one-room air conditioner uses.
  • Apply Some Cold. If a cooling breeze isn’t enough to keep you comfortable, you can cool yourself directly with cold water or ice – taking a cold shower reduces your temperature immediately. You can also soak a cloth in cold water and drape it around your neck, one of the main spots where your body sheds heat. If that’s not cold enough, try an ice bag or a commercial cold pack that you chill in the fridge or freezer. You can buy cold packs at drugstores for about $10. Cooling vests are available for $100 to $300 with pockets for tucking in a cold pack so you can carry it on the go.
  • Bring Cooler Air In. At night, when the air is cooler, it makes sense to bring as much as possible of that cool air into your home. You can just open the windows, but a window fan, which costs less than $100, can pull in cold air much faster. A typical window fan uses no more than 70 watts of electricity.
  • Install a Whole-House Fan. If you want even more airflow, you can install a whole-house fan, which mounts in your ceiling and pulls in air through the open windows. According to Silicon Valley Power, these fans can move thousands of cubic feet of air each minute with just 500 watts of power. You should expect to spend a few hundred dollars on the fan and another few hundred to have it installed.
  • Use a Swamp Cooler. A swamp cooler, also called an evaporative cooler, blows warm air over water-soaked pads. As the water evaporates, it cools the air by as much as 40 degrees Fahrenheit, and it uses only 25% of the energy required to run an air conditioner, according to the DOE. Free-standing swamp coolers start at $120, and a whole-house evaporative cooling system can be installed for about $2,000. The main drawback of this type of cooling system is that it only works in dry climates. This map from the appliance company Air & Water shows which parts of the country are best suited for evaporative coolers.

two-way window fan exhaust

Run Your Air Conditioner Efficiently

In some parts of the country, a good fan and a couple of ice packs are all you need to survive the summer heat. But in the hottest, most humid areas, there’s pretty much no way to make it through a whole summer without switching on the air conditioner. So on those days when air conditioning is a must, the best way to save energy and money is to keep your AC system running as efficiently as possible.

How an Air Conditioner Works

Air conditioners are based on the physical principle that when a liquid gets converted to a gas, it absorbs heat. They work by circulating a fluid through a series of coils, evaporating and condensing over and over again. As the fluid evaporates, it absorbs heat, removing it from the air inside. When it condenses, it loses heat, which is released into to the air outside.

An air conditioner has three main parts:

  • Evaporator. This is the part of the air conditioner that sits inside the house. Warm air from the room gets sucked in to the evaporator through a filter and passes over a series of coils filled with liquid refrigerant. As the air cools, a fan blows it away from the evaporator and circulates it through the house.
  • Compressor. As the liquid in the evaporator takes in heat from the indoor air, it turns to gas. This gas flows into the compressor, which sits outside the house. The compressor squeezes the gas, increasing its pressure to aid its transfer back into a liquid.
  • Condenser. The hot, compressed gas is pumped into the condenser, where its heat gets transferred through a series of fins like those in a car radiator. A second fan blows across these heated fins to disperse the heat into the outdoor air. As the gas cools, it turns back into a liquid and flows back to the evaporator to start the process again.

Maintaining Your Air Conditioner

To keep your air conditioner running efficiently, you need to make sure all its parts are clean and in good working order. Fortunately, most routine AC maintenance is simple enough to do yourself.

Here are several tasks you should do regularly:

  • Clean the Filter. The AC filter helps keep the evaporator clean and also filters particles out of your interior air. Over time, the filter itself gets clogged with these particles, making it harder for air to pass through. This forces the evaporator to work harder to cool the same amount of air, and your energy bills go up. According to the DOE, a dirty filter can lower your system’s efficiency by 5% to 15%. Inspect your filter at least once a month and clean or replace it if it’s dirty. The manual for your AC unit should explain how to do this. Some filters are disposable, while others can be cleaned and reused. Most disposable filters cost less than $10, while reusable ones cost between $30 and $100. To clean a reusable filter, vacuum it to remove debris, wash it in warm, soapy water, and let it air dry before putting it back in place.
  • Clean the Coils. While you’ve got the filter out, you can easily check the evaporator coils for dust or debris, which can be gently removed with the upholstery attachment on your vacuum cleaner. You should also clean the coils and fins on the condenser at the start of each summer by rinsing them with a hose. On a central air conditioning unit, shut off the power at the appliance shutoff box or circuit breaker before cleaning the coils. A window air conditioner should be unplugged and removed from the window for cleaning.
  • Align the Fins. When you clean the fins on the evaporator and the compressor, check to see if any of them are bent. If they are, you can straighten them with a tool called a fin comb, which you can purchase from a home center for about $10.
  • Clear Away Debris. If you have a central AC system, you need to keep the condenser unit clear of debris such as tall grass or dead leaves. This kind of clutter restricts air flow around the condenser so it can’t disperse heat as effectively. Remove weeds and other debris when you clean the condenser at the start of each season.
  • Clear Clogs. Your air conditioner’s evaporator doesn’t just remove heat from the air – it also removes moisture. This excess water gets drained outside through a pipe called the drain line or condensate line. Over time, this pipe can get clogged with dirt and debris. To prevent this from happening, run a stiff wire through the drain lines from time to time to push out any blockages.
  • Check Seals. A window air conditioner has a seal around the edges where it fits into the window frame. Moisture can gradually damage this seal, allowing cool air to escape. Inspect AC seals each summer to make sure they’re making contact with the unit all the way around, and replace them if they’re damaged. A new foam seal costs just a few dollars.
  • Cover It Up. When cold weather comes, cover the outdoor parts of your central air conditioner to protect from debris and harsh winter weather. If you have a window air conditioner, either cover it or put in in storage for the winter.

Reducing AC Energy Use

Aside from regular maintenance, there are several other steps you can take to reduce the amount of energy your air conditioner uses. For example:

  • Adjust the Thermostat. According to Bluejay, for every degree you set your air conditioning below 78 degrees, you increase your energy usage by 3% to 4%. That doesn’t mean you should keep the indoor temperature so hot that you’re stifling, but don’t just assume that you need to keep it at 70 degrees year round. Instead, experiment. Wear lighter clothing, use an ice pack, or turn on a desk fan, and you can stay comfortable with the thermostat set at 80 degrees or even higher.
  • Seal Your Ducts. If your home has forced-air heating, you could be losing as much as 30% of your cooled air to leaky air ducts. You can hire a contractor to find and repair holes and leaks in your ductwork or do it yourself with mastic sealant or metal tape. But don’t use duct tape – despite its name, it does not do a good job of sealing ducts because it dries out. In some areas, the local utility will test your home’s ductwork for leaks for little or no cost.
  • Set a Timer. There is no point in running your air conditioner all day long if nobody is home. Many central and window AC units have built-in timers, so you can set them to switch off automatically when you leave for the day and turn back on half an hour before you arrive home. That should be enough time to get the house cool and comfortable by the time you arrive. Don’t worry about wasting energy by starting your air conditioner in the evening in a warm house – an experiment done by Bluejay shows that this uses significantly less energy than letting it run all day.
  • Use a Programmable Thermostat. If your air conditioner doesn’t have a timer, you can set it to shut off in your absence with a programmable thermostat. You can also use a programmable thermostat to keep the temperature at one steady level during the day and another at night, rather than fiddling constantly with the controls. The DOE says using a programmable thermostat can save you up to 10% on your year-round heating and cooling costs.
  • Use the Energy Saver Button. On most window air conditioners, the compressor shuts off when the room reaches the desired temperature – but the fan continues to run, wasting energy. However, many units have an energy saver button that turns off the fan when the compressor shuts off. According to another test by Bluejay, the fan by itself uses about 85 watts of energy, so letting it run unnecessarily for 12 hours a day would use more than 30 kilowatt-hours of energy per month.

One energy-saving tip you should ignore is the suggestion to close the registers in rooms you don’t use, such as a spare bedroom or formal dining room. A 2003 study at the Lawrence Berkley National Laboratory found that in a typical house, doing this actually increases the air conditioner’s energy use because it leads to more leakage in the duct system.

repairing an air conditioner

Upgrade Your Air Conditioning System

According to the DOE, the most efficient central AC systems today use 30% to 50% less energy than those built in the mid-1970s. Even compared to a 10-year-old unit, a new air conditioner can cut cooling costs by 20% to 40%. So if you currently spend $200 a year on summer cooling like the average American household, upgrading your system could save you up to $100 a year.

However, if your central AC system still works, you probably won’t save any money by replacing it with a new, more efficient system. Buying and installing a new central AC system costs between $3,500 and $4,000 on average. So your new system will take at least 35 years to pay for itself – if you own the house that long.

If your old AC system needs replacing anyway, it’s worth choosing an energy-efficient one. The efficiency rating of a central air conditioner is called its seasonal energy efficiency ratio (SEER). This is a measure of how much energy it uses to produce a specific cooling output. Old air conditioning systems often have SEER of 6 or less, while modern systems can reach 20 or more.

The size of your system is also important. If your central AC system is too small for your house, it won’t be able to cool the entire space on the hottest days. On the other hand, a system that’s too large for the house will cost more and may not do as good a job distributing cold air.

Another question to consider before replacing your central air conditioner is whether to switch to a different type of system that uses less energy. For instance, you could choose:

  • Window Units. There’s no point in cooling a whole house if you’re using only a few rooms. If you tend to spend most of your day in a single room, such as your home office, perhaps you can skip the central air conditioning and just use a window air conditioner in that one room. A new window air conditioner typically costs between $110 and $300 and uses around 900 watts to run. Even if you have to install window units in several rooms, it’s cheaper to cool one room at a time than an entire house at once, and there’s no energy lost to leakage through the duct system. However, if you really need to cool multiple rooms simultaneously, a central AC system is more efficient.
  • A Mini Split System. Instead of using a single evaporator and a fan to cool the whole house, these systems have several indoor air handling units hooked up to a single condenser and compressor. This setup allows you to cool specific rooms that are in use instead of cooling the whole house. It also eliminates the need for ductwork, so there’s no air leakage. Mini split systems are easier to install than central AC systems, especially in houses that don’t already have forced-air heating. Their main drawback is that they’re usually more expensive. A ductless air conditioning system costs around $5,000, while a central air conditioner costs $3,500 to $4,000 in a house that already has heating ducts. In a house with no ductwork, however, the cost of a central air conditioning system jumps to $7,000 to $8,000, making a split system the more cost-effective choice.
  • A Geothermal System. A normal air conditioner transfers heat from your house to the air outside, which, in the summer, is pretty hot already. Geothermal systems, by contrast, transfer indoor heat to the ground about 10 feet below the surface, which stays at around 54 degrees Farenheit all year long. One advantage of geothermal systems is that you can use them for heating your home in the winter, as well as for cooling it in the summer. A geothermal system costs about $3,500 more than a conventional heating and cooling system, but you can get an ENERGY STAR tax credit to cover part of the cost, and it can save you more than $30 a month on home heating and cooling bills.

Final Word

One thing you shouldn’t do to save on your summer cooling costs is let the temperature in your house climb to dangerous levels. When the temperature is above 90 degrees and the humidity is also high, your body can no longer cool itself by sweating, putting you at risk for heat-related illnesses, such as heat exhaustion or heat stroke. If you start to have symptoms of heat illness (such as extreme thirst, muscle cramps, fatigue, headache, dizziness, or nausea), forget about your electric bill and cool yourself as quickly as possible.

Fortunately, there’s no need to put yourself in danger – or even discomfort – just to save money. By combining the tips listed here, you can take a big bite out of your summer electric bill without having to swelter in an overheated house.

What’s your favorite trick for staying cool in the summer?