Air conditioner usage varies based on the size of your AC. However, generally speaking, a central air conditioner will consume between 3000 and 3500 watts per hour. While window units use between 900 and 1440 watts per hour, portable units consume between 2900 and 4100.
The short answer is yes, it is cheaper to leave your air conditioner on all day. But this does not mean that you should leave it on full blast, keeping your home so cold that you need a sweater or jacket to be comfortable.
A 220-volt supply can transmit the power more cheaply because a smaller current is needed, and so you can use thinner cables and/or lose less energy through heat generated in the cables.
Every degree above 78 saves about 2 percent on your bill, while every degree below costs an extra 6 percent. Fans are cheaper to run than air conditioners, and can be used in place of air conditioners or along with them to save money. If you have a ceiling fan, run it at the same time as the AC.
Leaving your air conditioner on is actually more efficient than frequently turning it on and off. Having your AC on also allows you to better control humidity in your home throughout the day.
If you left the unit on during the day, it would turn on and off throughout the day. If you live in a colder climate where your HVAC does not have to work as hard to maintain a comfortable temperature, turning your air conditioner off during the day could help you save money.
Benefits of keeping a relatively constant temperature
Alongside substantially lowering your energy costs and extending the lifespan of your AC unit, there can be additional benefits to your home such as keeping your hardwood floors and wooden furniture in better condition.
If you set your preferred temperature very low, your air conditioner is still going to run longer than necessary. But using the AUTO setting with a reasonable set temperature will keep your energy costs low, especially if you turn your unit off when you're away from home or asleep.
For many, 72 degrees is the optimal indoor temperature, but on days that surpass 92 degrees your AC will be running extra hard to meet those expectations. When outside temperatures are pushing 100 degrees, try setting your thermostat at 78-80 degrees.
Anyone who's opened an eye-popping energy bill in the middle of winter or one for air conditioning in the summer has probably wondered which system costs more to operate. According to analyses, it's no comparison: heating your home requires four times more energy in the US than cooling your home.
The simple answer to that is that they are almost the same cost to operate or are just within a few dollars. Most people think that 240V is cheaper because it uses half the amps that 120V uses. Amps isn't what consumers pay for, it's actually the wattage used by the electrical device.
According to the Department of Energy1, 78° Fahrenheit is the sweet spot for air conditioners to balance energy savings and comfort when people are at home and need cooling.
Debunking a Common Air Conditioner Myth
While this might sound logical, this is actually 100% false. Why though? Sure, turning your air conditioner on uses energy, but if you're keeping your air conditioning system on at all times (including when you're not home) you're not using your air conditioner efficiently.
Can I leave my air conditioner on all night? While we've established that falling asleep with the AC on can help you sleep well, leaving it on all night might actually be harmful to your health and sleeping cycle.
According to the GHI, placing a bucket of ice in front of a fan as a homemade AC unit is just as effective. 'As the air passes over the ice it will be chilled and will circulate refreshingly cold air around the room,' they explain.
"It's more energy efficient to keep the unit on but turn the temperature setting up," she advises. Turning off the AC unit during the day is not necessarily a bad thing — it is a myth that the AC unit has to work extra-hard to cool off a hot house.
In general, it is cheaper to leave the AC on all day during very hot temperatures. However, it's not efficient to keep it on full blast all the time. Your exact results may vary depending on your AC system. So, it's best to consult a professional if you aren't sure about how to lower your energy bills.
We'd actually suggest keeping your home's thermostat in between 72 degrees and 76 degrees to make things as simple and straightforward as possible for your home. It's a reasonable temperature that will keep you cool without overworking your AC.
How cool should my house be if it's 100° outside? The majority of air conditioning units are designed to only cool the air about 20 degrees from the outside temperature. If the temperatures outside are approaching triple digits, you should set your thermostat at about 78°.
Best AC Temperature Settings While You Are Home
The U.S. Environmental Protection Agency suggests that people set their air conditioners to 78 degrees in summer while they are home for maximum savings on their utility bills.