Running the Numbers on Your Air Conditioner

The U.S. Energy Information Administration (EIA) calculates that nearly 20% of your annual electricity use goes directly to your air conditioner. EIA data also shows that the average residential customer in the US used 11,000 kilowatt-hours (kWh) in 2016.

Even with that data, it can be difficult to give a clear answer to the question of how much electricity your HVAC uses in the summer because it depends upon several factors:

• The size of your air conditioning unit
• The type of air conditioner (i.e. window or central)
• The thermostat setting you choose
• How long your air conditioner runs throughout the day

Without knowing all of this highly specific information about air conditioning in your home, we can’t give you an exact answer, but we can point you in the right direction so you can calculate it yourself.

Analyzing the Information

The air conditioning experts over at All Systems Mechanical have created a helpful walkthrough that breaks down the different details into manageable chunks and straightforward math. We’re going to simplify their guide even further.

• Just like your microwave and other electrical devices, your air conditioning unit is rated at a certain number of Watts.
• A kilowatt-hour is a unit of measurement commonly used by electricity companies regarding your electricity usage, as it’s simply a way to determine how many kilowatts of energy you use in one hour.
• The average sized air conditioner for a typical residential HVAC system in a house is 3,500 Watts.
• Since 1,000 Watts equals 1 kilowatt, your 3,500-Watt air conditioner unit will use 3.5 kilowatt-hours if you run the unit consistently for one hour.
• Summer technically lasts 3 months, which is 90 days, and with 24 hours in a day, the season lasts 2,160 hours.
• If your AC uses 3.5 kWh for 2,160 hours, that becomes 7,560 kWh used in the summer.

And if you factor in what your energy company charges for electricity usage, you quickly begin to see how your air conditioner greatly impacts the size of your energy bills.

Lowering Your Electricity Usage

Now, we’ll be the first to admit that your air conditioner does not and should not run for all of those summer hours. Because if it does, not only will you face a very large electricity bill for the summer, but your entire air conditioning unit will fall into disrepair long before it should.

Thus, we want to give you a few tips to help you lower your electricity usage for the summer.

1. Set your air conditioner thermostat between 75-78° F (23.8-25.5° C) when you’re home.
2. Set your air conditioner thermostat between 82-85° F (27.7-29.4° C) when you’re away from home.
3. Point your ceiling fans to where air flows into the center of the room.
4. Save your heavy appliance usage until after 8pm.

The best way to control how much electricity your air conditioner uses in the summertime is to find a balance between how hot it is outside and how cool you need it to be inside. Because if you combat the summer heat with a super-low thermostat setting, your air conditioner will truly run all the time to keep your house cool. Not only will that certainly drive up the amount of electricity you use, but it will give you a very substantial electricity bill.