How to make your air conditioner more energy-efficient
As summer lingers on, you're likely enmeshed in some version of the following daily ritual: get home, drop bag, turn on air conditioner, bask in cool breeze. But with your AC unit rumbling to life day after day, you've probably noticed an uptick in your electric bill — not to mention how much energy you're using just to feel that cold air.
Because people generally want to be comfortable in their homes (the nerve), air conditioning can often "operate around the clock, quickly becoming the largest user of electricity in your home," Amy Gebrian, a senior product manager at heating and cooling company Lennox International, tells Mic. Federal statistics show that AC units alone account for about 12 percent of U.S. home energy expenses, and can make up as much as 27 percent in hot and humid places like Louisiana and Florida. That means that adjusting your AC habits to be more energy efficient could be a huge boon for your overall energy usage — not to mention easier on your wallet.
So how do you do that? First, it's important to get a sense of your current situation. Matthias Alleckna, an energy expert at EnergyRates.ca, tells Mic that your energy usage will depend on certain details, like your AC's wattage consumption and the electricity rates in your region. The rates are especially important, because different rates in different regions could mean your energy bill is wildly different from someone who has the same AC model as you but lives in a different city.
From there, there are a few ways to make your air conditioner usage more energy efficient and less costly to you. (Of course, the ultimate way is to use your AC unit less, but we know that's not always feasible during the peak of summer.)
Take good care of your air conditioner
Gebrian says it’s important to get your air conditioner checked by a licensed heating, ventilation, and air conditioning (HVAC) contractor on an annual or semi-annual basis. “Air conditioning systems will operate the most efficiently if properly maintained — dust, dirt, animal fur, and other items that are trapped by the filter can reduce air flow and cause the system to use more energy if filters are not checked, cleaned, or replaced regularly,” she explains.
Ben Garvey of Energy Upgrade California says you can swap out your filters even more often than that in the summer — like once every 1-2 months. Diligent replacement could "lower your energy use by five to 15 percent,” he says, and he also advises cleaning the coils and drain channels.
An HVAC professional can additionally help you figure out exactly how much energy you're using by measuring amp draws and wattage, and that person could suggest solutions tailored to your set-up. And if you just generally feel you’ve been running your AC a lot, looking at your last few utility bills can help you see any increase in usage. Installing a smart meter can also help you keep track, Gebrian says.
Consider getting a more energy-efficient model
Another easy trick is to check whether you have the most energy-efficient AC unit possible. If not, you may want to invest in a new one. “You’ll want a system that steadily adjusts to meet your level of comfort — you’ll commonly hear this referred to as a ‘variable-speed’ system,” Gebrian explains. These are the most efficient systems you can buy, so if you get one you can rest assured that you'll be saving energy.
Garvey of Energy Upgrade California also suggests purchasing an ENERGY STAR-certified air conditioner — it’ll be 15 percent more efficient, he says, and in some cases buyers are eligible to receive rebates from their energy company for purchasing one.
While there are some products that are more efficient than others, it’s hard to give a one-size-fits-all answer to which AC unit is better for you. “For spot cooling, you can use compact room window units, especially if you are budget-minded,” Stephany Smith, an electrician at Fantastic Services, tells Mic. “On average, the contemporary, powerful window units use 2.5 less energy than central AC systems.” But if you need to cool a larger area, window units may not be the most efficient, Smith says. The most important thing to keep in mind is to only run the AC where and when you actually need it.
Maximize your home
There are only so many ways to hack your air conditioning system, but certain modifications to your home can also boost your AC efficiency. Properly insulating and sealing your air ducts, for example, can reduce an air conditioning system’s energy use by 30 percent, Garvey says. “Inspect the seal between your unit and the frame to ensure no leaks,” he advises. Pay special attention to attics and walls, which he says are "classic culprits of warm air leaks that jeopardize the efficiency of a system.”
Other physical modifications to consider: energy-efficient windows, dark window treatments, and reflective roof materials, all of which can help maximize the effect of your air conditioner while also warding off some of the sun's heat themselves. Even your ceiling fans can be hacked: Run them counterclockwise during the summer, Alleckna says, and check to see if your fan has a "summer mode" to redistribute cold air more effectively. It’s also helpful to use heat-generating appliances such as the oven, stove, or microwave less often.
Additionally, remember that the temperature you set on your thermostat or air conditioner doesn't correspond to the temperature of the air flowing through the system, but rather the overall temperature of your home compared to the outdoors. “The lower the target temperature is compared to the outside temperature, the more the system will need to run," Gebrian explains, because it will take longer to cool your home. The target temperature only tells the air conditioner when to turn off, not how cold the air should be that it's blowing out. Per Joey Gibellino of California-based Alps Heating and Air Conditioning, ENERGY STAR suggests setting your thermostat to 78 degrees for an energy-efficient temperature that is still comfortable.
It can also be helpful to use a programmable or smart thermostat to keep tabs on things. The latter works through a phone app, as well as through smart home devices such as Alexa. “These can automatically increase your system’s efficiency by adjusting the temperature when you’re away and readjusting to your perfect level of comfort upon your arrival back home,” says Gebrian. Garvey agrees: “It is an easy and effective way to cut down on energy consumption and save up to 10 percent on annual heating and cooling costs,” he says.
With temperatures seemingly getting hotter and hotter in the U.S. and abroad, it's hard to ignore the question of whether climate change is contributing to excessive AC use and energy consumption. “Without getting political: Yes,” says Gibellino. “It affects my business, so I recognize that it is getting warmer and customers are using their AC systems more and more."
But it's not all doom and gloom, he says: "As a result, manufacturers are building AC units that are more and more energy efficient.” Now that's refreshing.