Spring and summer are fast approaching. Across the U.S., we’ll be checking our air conditioning systems to make sure they have enough energy for hot and muggy weather. Speaking of energy, the question is how many watts does a central air conditioner use and need to operate at peak capacity?
Knowing how many watts a central air conditioner uses is key, because without having an energy-efficient and powerful air conditioner unit, you could find yourself broiling before summer even hits.
Not to worry, though. Streamline Air here. We’ve got your back.
We’ll walk you through what you need to know about air conditioner energy usage to help you stay cool and comfortable year-round.
In this article, we’ll discuss:
- How an air conditioner’s power depends on three terms: amperage, voltage, and watts
- How many watts three different popular types of air conditioners use
- How to calculate the cost of general air conditioner energy usage
- Tips for reducing energy usage with an air conditioning system
- The importance of keeping a handy air conditioner specialist’s contact information at the ready
An air conditioner’s power depends on amperage, voltage, and watts
Amps, watts, and volts: these terms might seem familiar when shopping for electronics. But did you know these short-hand terms are also related to your air conditioner?
Knowing about amperage, volts, and watts is key for making the most of your air conditioning system and reducing common A/C issues. Let’s look at three common energy terms — amperage, voltage, and watts — as they relate to how much energy a central air conditioner uses.
Amperage for air conditioners
Amperage — measured in amperes or amps (A) for short — measures the strength of the electrical flow or rate of flow of a current of electricity.
You’ll need to have a solid understanding of the amps used by your air conditioner from both a safety and efficiency standpoint. Knowing how many amps your air conditioner needs will help ensure you don’t overload your power system and cause electrical issues (like tripped breakers).
Knowing which air conditioner matches your home’s wiring and electricity is key to preventing electrical issues related to amperage in an air conditioning unit.
Air conditioner voltage joltage
Careful! Air conditioner voltage is no joke.
Volts relate directly to air an air conditioner’s electricity usage.
To avoid jolts from an air conditioner, we need to learn a bit about voltage. Voltage is the pressure in an electrical circuit that pushes the electric current through the circuit.
We measure voltage by volts (V). Voltage is the electrical potential of electricity that passes through a circuit.
The more volts the unit uses, the more powerful the pressure inside the unit. Volts are what those “Caution” signs say near power lines and other electrical systems.
An air conditioner’s transformer is responsible for providing a power supply of electricity to HVAC control components. But, a transformer also takes higher-voltage to lower voltage to operate air conditioner-related systems like the thermostat, control board, sensors, relays, and more.
The more you know about volts, the fewer potential jolts you’ll likely experience with your HVAC system.
Watt’s up with an air conditioner unit’s wattage
The moment we’ve all been waiting for: watts. Watts (W) and kilowatts (kW) are measures of energy and power consumption.
A kilowatt is the equivalent of 1,000 watts. You can think of watts as the byproduct of volts and amps.
To calculate wattage, we multiply bolts by amps.
So, what’s the big deal with watts? Why are they important?
Well, for one, electrical companies charge for the usage of electricity based on kilowatt hours (kWh). Floor lamps, coffee makers, blenders, and air conditioning units are powered by watts.
Each electrical appliance — your HVAC included — has a power rating telling you how much power the appliance needs to operate.
For air conditioning systems, we use a seasonal energy efficiency ratio (SEER) to calculate how energy-efficient an HVAC system is. For example, to calculate the SEER ratio of an HVAC system, you calculate the cooling output of an air conditioner or heat pump in a typical season and divide this number by the energy the A/C unit produces.
The result is your SEER rating, which is calculated in watt-hours. For an air conditioning system, the less power it needs, the higher the SEER rating.
Knowing the stated wattage for different types of air conditioners can help you not only discover how much energy an air conditioner uses, but also the cost of running an air conditioner.
Next, we’ll turn to three different types of air conditioners and their stated wattage.
How many watts do air conditioners use? 3 types
Knowing how many watts an air conditioner uses depends on the cooling system. In general, three types of air conditioners exist:
- Central air conditioners
- Heat pumps
- Ductless mini-split systems
Let’s gain a better understanding of how many watts of power each uses.
1. Central air conditioner wattage
Central air conditioners tend to use between 15 and 60 amps based on how large the air conditioner unit is. A central air conditioner uses about 1,000 watts per ton of cooling capacity.
For example, a 2,000-square-foot home needs about 3.5 tons of cooling power, so the average power of a 3.5-ton air conditioner is about 3,500 watts per hour,
In general, most central air conditioner units use about 3,000 to 4,000 watts. The great news is that, since the A/C cycles on and off throughout the day, it tends to have lower running wattage.
2. Heat pump wattage
Since heat pumps provide both heating and cooling, they tend to use more watts. Air-source heat pumps tend to need 240 volts and a dedicated circuit.
Watt usage depends on the size of the heat pump and how often the homeowner uses the air conditioner. In general, though, heat pumps can range between 20 and 50 amps and use anywhere from 1,000 watts to 7,500 watts depending on how many tons the heat pump weighs.
3. Ductless mini-split air conditioning system wattage
Finally, we come to ductless mini-split systems. Most ductless mini-split systems use 230-240 volts, but some smaller units only need about 110 or 120 volts to operate.
Depending on the BTU capacity — which stands for British Thermal Unit, a measurement used to determine the cooling capacity of an air conditioner — a ductless system will need 15-45 amps to work.
Expect a mini-split system to use anywhere from 500 to 1,500 watts per hour. Larger mini-split air conditioning systems use up to 5,000 watts per hour.
Also, mini-split systems need a dedicated electric circuit; indoor units need a surge protector.
With all of the above-mentioned air conditioners, the amount of energy used per day will vary depending on the size of the unit, how often it’s used, and the type of climate in which it operates.
How to calculate the cost of A/C energy usage
At this point, you might wonder, “Now that I know how many watts my A/C unit takes, how do I calculate its energy consumption?”
If you want to determine the average energy cost of an air conditioning system, we need to use a few formulas and do a bit of arithmetic.
Three common formulas help determine the cost per hour of energy expended on an air conditioning unit.
- Cost of energy per hour = (unit wattage × average cost per kilowatt hour) ÷ 1,000
- Cost of energy per month = (unit wattage × hours of use per day × days of use per month × cost per kilowatt hour) ÷ 1,000
- Cost of energy per year = (unit wattage × hours of use per day × days of use per year × cost per kilowatt hour) ÷ 1,000
While these figures won’t give you an exact number, they provide a solid ballpark number to help you make more informed decisions for your air conditioner and electricity-based needs. At the end of the day, your energy costs will vary based on factors, such as:
- The size and efficiency of your HVAC system
- The climate of your place of residence
- The size of your home
- How well insulated your home is
- To what extent airflow can move through your home
- The outdoor temperature
- How often you use and at what temperature you set your cooling system each day
Tips for reducing air conditioner energy usage
We’ve talked a great deal about power, watts, and amperage usage. With U.S. energy consumption at some of the highest levels they’ve been in the last 50 years (Statista.com, 2024), knowing how to reduce your air conditioner’s energy is of utmost importance.
You can reduce your air conditioner’s energy usage by trying some of the following handy tips:
- Follow through with a regular air conditioning maintenance schedule: replace air filters and conduct regular A/C maintenance and repairs to help ensure your system operates at ideal energy levels.
- Consider using ceiling fans: though the Florida heat can be tough, you can opt for ceiling fans and lower thermostat settings to help distribute cool air and keep your energy usage lower.
- Set your thermostat to warmer temperatures while away from home: if you’re not at home, you can always set your A/C unit’s thermostat to a higher temperature to save on utility bills while you’re away.
- Shutter blinds, close curtains, and keep doors closed: all of these steps can help block sunlight, prevent heat from building up, and reduce the amount of energy expended by your air conditioner.
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Sarasota, FL county: enjoy more comfortable indoor living with Streamline Air
In summary, a central air conditioner uses anywhere from 3,000 to 4,000 watts depending on how many tons the air conditioner unit weighs. For example, small window units will likely use fewer watts than a residential or commercial central air conditioner unit.
You can keep your home cool by opting for more energy-efficient air conditioners, conducting regular air conditioning repair and maintenance work, and opting for air conditioners with the right energy efficiency rating for your home’s cooling needs.
Plus, if you need a little help finding the right air conditioner for your needs, you can always contact us. At Streamline Air, we’re all about providing straightforward answers and simplified solutions for your heating and cooling needs.
Schedule your zero-risk, free air conditioning and/or indoor air quality consultation today. Until then, be well and stay cool!
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