Introduction – How Much Electricity Does Air Conditioning Use
Air conditioning consumes 22% of household electricity every year. In fact, it is the biggest consumption of electricity in the household in the US. It’s not necessarily the largest consumption of energy because in cold climates heating consumes energy in the form of both electricity and natural gas and oil. Most of air conditioning use is concentrated in the summer months, which in the Northern Hemisphere is June, July, and August, whereas in the Southern Hemisphere is December, January, and February.
Here we show you the electricity used by 3 types of air conditioners and the average US use over the year and for each month during the 3 summer months. We show units of MBTU (million BTU) or kWh. If you don’t understand what is a 1 ton vs 4 ton AC, then think about your living space. A small apartment would be 1 ton of cooling required, and a medium sized house would be 4 tons of cooling required.
|Annual electricity MBTU (kWh)||Summer monthly MBTU (kWh)|
|Central AC 1 ton||6.4 MBTU (1,867 kWh)||2.1 MBTU (622 kWh)|
|Central AC 4 tons||25.1 MBTU (7,467 kWh)||8.4 MBTU (2,489 kWh)|
|Window unit||7.4 MBTU (2,160 kWh)||2.5 MBTU (720 kWh)|
|Average use in US||7.5 MBTU (2,200 kWh)||2.5 MBTU (733 kWh)|
We also show you the electricity cost of 3 types of air conditioners and the average US use over the year and for each month during the 3 summer months. We assume 16 hours of use per day, which is on the high side. If you use only 8 hours a day for example, just reduce the cost by 50%. We use the electricity rates for each country found below.
|Country||Central AC 1 ton annual cost (monthly)||Central AC 4 ton annual cost (monthly)||Window AC annual cost (monthly)|
|US||$298 annual ($99 monthly)||$1192 annual ($397 monthly)||$345 annual ($115 monthly)|
|UK||$765 annual ($255 monthly)||$3061 annual ($1020 monthly)||$886 annual ($295 monthly)|
|Ger||$877 annual ($292 monthly)||$3509 annual ($1169 monthly)||$1015 annual ($338 monthly)|
|Australia||$410 annual ($137 monthly)||$1642 annual ($547 monthly)||$475 annual ($158 monthly)|
|Canada||$224 annual ($75 monthly)||$896 annual ($298 monthly)||$259 annual ($86 monthly)|
|Japan||$448 annual ($149 monthly)||$1792 annual ($597 monthly)||$518 annual ($173 monthly)|
|China||$149 annual ($50 monthly)||$597 annual ($199 monthly)||$173 annual ($58 monthly)|
|France||$373 annual ($125 monthly)||$1493 annual ($498 monthly)||$432 annual ($144 monthly)|
How We Computed The Electricity Use And Cost
We started by considering three types of air conditioner units.
1. Electricity Used By A Central AC Unit – 12,000 BTU (1 ton) to 48,000 BTU (4 tons)
2. Electricity Used by A Window AC Unit – 1.5 kW (1500 W) which is about 5,000 BTU
3. Average AC Electricity Used By A Household In US – Using statistics of the average AC electricity usage values.
BTU vs kWh or BTU / hr vs kW
We made sure to work in both units of energy. The BTU (British Thermal Unit) is a measure of energy used to describe the heating or cooling capacity of a system, such as a furnace or air conditioner. It is the amount of energy it takes to raise or lower the temperature of one pound of water by one degree Fahrenheit. The other unit, kWh (Kilowatt-hours) is the amount of energy used in one hour by a device with a power rating of one kilowatt. The two are both units of energy and the conversion is as follows:
1 BTU = 0.00029 kWh
1 kWh = 3,412 BTU
Very closely related to this is the units of power which is the energy used per unit of time. For the above, the units of power are BTU / hr or kW (kilowatts) which is the same as kWh / hr. We might say an AC is rated to be 1.5 kW, meaning it uses 1.5 kW per hour. So in an hour period, it would use 1.5 kWh. Similarly we might say an AC is rated 5,000 BTU, meaning it consumes electricity at the rate of 5,000 BTU / hr and that in one hour it would use 5,000 BTU.
Electricity Rates In Different Countries
We picked out a few electricity rates for comparison. We use the US dollar to standardize and make comparisons possible. The conversion rates are from Jan 2023.
|Country||Electricity Rate ($ / kWh)|
|US||$0.16 / kWh|
|UK||$0.41 / kWh|
|Germany||$0.47 / kWh|
|Australia||$0.22 / kWh|
|Canada||$0.12 / kWh|
|Japan||$0.24 / kWh|
|China||$0.08 / kWh|
|France||$0.20 / kWh|
Simplifying Assumptions To Calculate The Electricity Used By Air Conditioning
We imposed simplifying assumptions otherwise this post would become a 15 page research paper.
We ignored the fact that all of our readers live in different climates, with different kinds of summers because that impacts how much you use the air conditioning. We will ignore the fact that our readers have different kinds of insulation. Excellent insulation such as that found in rare passive houses can obviate the use of air conditioners completely whereas very poorly insulated houses will have continuously running air conditioners.
The only thing we considered is that the air conditioner is used for 3 months (Northern vs Southern Hemisphere such as Australia are different), and that you will run the unit 16 hours a day from morning till night. We will also explore 2 different air conditioner sizes below for the central units.
Electricity Used By A Central AC Unit
Central air conditioning units are conventionally measured in tons with 1 ton equating to 12,000 BTU, and 4 tons equating to 48,000 BTU. One helpful relation is that every square foot of space requires 20 BTU. So a medium sized house in the US at 2,000 sq ft would need 40,000 BTU which is a 4 ton unit. A small apartment that’s only 500 sq ft would need 10,000 BTU or a 1 ton unit. This is the amount of cooling.
To get the electricity cost needed to generate this amount of cooling, we need to know the SEER or HSPF ratings. To make it simple, we’re going to assume that these ratings boil down to an efficiency rating which is the amount of electricity needed to generate the cooling. A typical efficiency is 2.7 so for the numbers below we would divide by 2.7 to get the kWh of electricity.
Running a 1 ton unit (12,000 BTU/hr or 3.5 kW) for 16 hours a day over 3 months would require 6.4 MBTU (million BTU) or 1,867 kWh.
Running a 4 ton units would require 25.12 MBTU or 7,467 kWh.
Electricity Used By A Window AC Unit
A window unit plugs into an electrical socket which sits on one circuit of a house. The maximum power draw from a circuit is usually 1.8 kW so air conditioners stay a bit below that at 1.5 kW max. In this case we use the power draw number directly because window ACs aren’t always given in terms of the tonnage as in the central ACs.
Running a 1.5 kW (5,118 BTU) unit for 16 hours a day over 3 months would require 7.37 MBTU or 2,160 kWh
Average AC Electricity Use For US
Because the average house uses about 10,000 kWh per year, and 22% of that electricity use is air conditioning, we can easily get that 2,200 kWh is used for air conditioning every year. Note that this number is very different from the considerations above of a single AC unit. This is because many Americans don’t have an AC or don’t use an AC. When you average this over the population you get weird effects like it seems everyone is just using a window unit.
How Much Does Air Conditioning Cost To Maintain?
Additionally, the proper upkeep and maintenance of your AC unit can dramatically reduce running costs by around 30%. Therefore, while it’s difficult to determine how much AC will cost you each month, with proper research and care, you should be able to keep costs manageable.
Factors that Determine Air Conditioner’s Electrical Consumption
You can save on electricity costs and reduce your use of resources by understanding the factors influencing how much electricity an air conditioner uses. Factors include the size and type of the AC unit, insulation levels in your home, whether or not you have a programmable thermostat, and changes in temperature outside. Here are some of the most common factors to consider:
Size of AC Unit
Larger air conditioners draw more electricity, so the size of the AC unit will impact how much energy it uses. 20 BTUs per hour is the minimum amount of cooling power needed for a 150 sq. ft. area, so if you have a very large space to cool, it will take more energy.
Type of AC Unit
Central air conditioning units are typically much more efficient than window models, as they can cool an entire house with one unit and do not require multiple units for different rooms. Central air conditioning systems typically use 2 to 5 kilowatts of electricity an hour.
Insulation greatly affects how much energy your AC unit needs to use since it helps keep hot air out of your home or office during the summer months. Fortunately, insulation is relatively inexpensive and easy to install yourself.
By utilizing a programmable thermostat, you can have ultimate authority over the ambient temperatures of your home and inherently lower energy bills caused by AC unit consumption. By setting it for higher temperatures when no one is in the house, such as at night or while you’re at work, you can significantly reduce how much electricity your air conditioner needs to use.
Hotter outside temperatures require more electricity from air conditioning than cooler ones. If you live in a particularly hot climate, be aware that this could mean using up more power than usual during peak summer months.
Regularly servicing your air conditioning unit can help it run more efficiently. This includes regularly changing the filters, cleaning the coils, and checking for any leaks or other signs of wear and tear.
Air Conditioner’s Efficiency Rating
Air conditioners have efficiency ratings which measure how much energy they use to cool a given space. The higher the rating, the more efficient an AC unit will be, allowing you to save on electricity costs over time.
By understanding these factors and following simple energy-efficiency practices, you’ll be able to reduce your energy use and save money on electricity costs. It’s important to remember that the cost of running an air conditioner will vary depending on the system’s size, type, and efficiency. Still, it’s always worth taking the time to research ways to make your AC more efficient.
Overall, air conditioners are essential for homes in hot climates and provide great comfort when used correctly. Understanding how much electricity air conditioning is used and the associated costs are important for making informed decisions about keeping cool during the summer months safely and economically. With proper maintenance, careful temperature settings, and energy-efficient practices, households can enjoy the convenience of an AC without breaking the bank.
Make sure your air conditioner is in a well-maintained state. Conditions like broken seals, freon or other refrigerant leaks that cause low freon, will reduce the efficiency of your air conditioner.
Air conditioners are usually powered by electricity, but some models are powered by natural gas or other fuel sources. The most common type of air conditioner is a central air conditioning unit connected to the home’s ductwork system. This type of air conditioner is more efficient than window models, as it can cool an entire house with one unit and does not require multiple units for different rooms.