Informational Guide

How Many Watts Does a Heat Pump Use?

Heat pumps are a great way of providing comfort to your home all year round. We explain how many watts a heat pump uses and what that might cost you.

by Josh M

HVAC appliances let you control the environment you live in by regulating the temperature, airflow, and air condition in your home. Alongside the cost of buying and installing the unit, it’s important to know how much it will cost to run these appliances such as heat pumps and air conditioning units.

This is why it’s important to understand the power consumption in watts for each unit. Heat pumps are an effective way of providing comfort to your home all year round. In this guide, we’ll explain how many watts a heat pump uses and what that might cost you.

Air Source Heat Pump Vaillant Aromtherm Plus

The amount of energy your heat pump uses will vary depending on a number of different factors. You must understand them fully as this will impact how much your heat pump costs to run and may influence which you choose to buy. Here’s a quick breakdown of the key factors:

Heat Pump Type

There are three main types of heat pump: air to air, water source, and geothermal. They each operate in a different way and consume power differently to provide heat to your home.

Geothermal heat pumps work by drawing heat from the ground into your home. These are more expensive to install but have low operating costs as they use very little energy.

Water-source heat pumps operate similarly but draw energy from water under the ground rather than the earth. They are slightly less efficient but still have very low energy consumption.

Air to air heat pumps are by far the most common. They work by transferring heat through the air into your home. These are far cheaper to install but will use more energy than the other types.

Concept of the Ground Source for Heat Pump GSHP System
Technology Component

The technology that goes into appliances like heat pumps advances every year. As the components within the heat pumps have become more advanced, they are more efficient, and you will need to use less energy to produce heat. Investing a bit more in a modern unit with a better compressor and heat exchanger can save you money in the long run.

Size & Output

Different sized heat pumps will have different energy requirements, and generally, the larger the unit, the more energy will be needed. The size of heat pump you go for will depend on the number of BTUs produced, as this is the amount of heat that will go into your home.

You should make sure that you have a heat pump that suits the size of your home, or you could end up with hot or cold spots and paying extra with your electricity bills.

Local Climate

Your heat pump will work to keep your home at an optimum temperature. If your climate changes regularly, then it will need to work harder in order to adjust, and this will cause it to draw more power. If you live in an area with cold winters and hot summers, then you should expect to pay more for electricity.

How Many Watts Does a Heat Pump Use?

Heat pumps use different amounts of wattage to power them and convert that energy into heat. It’s important to have a rough idea of the amount of the wattage and BTU so you can estimate the energy cost.

Below is a table with estimates for each pump which will hopefully give you a good idea of how much each type of heat pump will cost to run. For these examples, we’ve assumed an average cost of 13.4cents per kWh.

Heat Pumps Per Ton BTU Wattage (kW) Cost of Electricity
(dollars per hour)
2 Ton 24,000 7 0.93
2.5 Ton 30,000 8 1
3 Ton 36,000 10 1.34
4 Ton 48,000 15 2.01
5 Ton 60,000 25 3.35

How To Calculate The Power a Heat Pump Is Using

To calculate the exact amount of power a heat pump uses, you need to work out the Coefficient of Performance (COP). This might sound really complicated, but it’s not, so don’t worry. You just need to follow this equation:

COP = energy out / energy in

The energy out is the BTU per hour, so essentially, how much heat is being released into your home. The energy in is the wattage required to run it. You should be able to find all of the information in the product manual. You can then adapt the equation for an hour, month, or year based on the number of hours you would use it.

You will need to convert your BTU/hr into watts. 1 BTU/hr is 0.293W, so you can multiply the BTU by that to get it.

Here are some worked examples below:

Central Heating Pump Power Usage

Let’s say your central heating power pump is using 10kW and producing 36,000 BTU. We first need to convert the BTU into the watts:

36,000 x 0.293 = 10,548

10,548/ 10,000 = 1.05

This means that for every watt of energy you put in, you get 1.05 back out.

The number of watts used to power your device is measured in Kilowatts per hour (Kwh). To work out how many watts you’ll use to power this, you’ll just have to multiply it by the number of hours you are using it for:

1 hour = 10Kwh

Assuming you use your heating pump for 10 hours a day, here’s a breakdown of what it takes to run it:

1 day = 100Kwh

1 month = 3000Kwh

1 year = 36,000Kwh

Mini Split Heat Pump Power Usage

For a mini-split, you should expect it to be a little bit more efficient, and the BTU will be higher. Let’s say it takes 8W to power and it’s producing 42,000BTU.

42,000 x 0.293 = 12,306

12,306/8,000 = 1.54

This means that for every watt of energy you put in, you get 1.54 back out.

The energy used to power this would be as followed (based on 10 hours a day):

1 hour = 8Kwh

1 day = 80Kwh

1 month = 2400Kwh

1 year = 28,800Kwh

Geothermal Heat Pump Power Usage

Geothermal heat pumps use much less power but still produce a lot of heat, making them really efficient. In this example, we’ll say the geothermal heat pump uses 9W and produces 56,000BTU.

56,000 x 0.293 = 16,408

16,408 / 9000 = 1.82

This means for every watt of energy you put in, you get back 1.82, meaning you get almost double what you put in.

Again, assuming you use your heating pump for 10 hours a day, here’s a breakdown of what it takes to run it:

1 hour: 9Kwh

1 day: 90Kwh

1 month: 2700Kwh

1 year: 32,400Kwh

How To Save Money When Using a Heat Pump

Heat pumps can be expensive, but there are some tips to keep the overall cost down:

Get The Right Size

Your heat pump should match the size of your home or the area it’s operating in. If It’s too small, then it won’t heat it properly, and the pump will be working harder and using more energy to try and achieve its goal. On the other hand, if the heat pump is too big, then it will be using energy it doesn’t need to, and it will be much less efficient.

Clean And Maintain The Heat Pump

You should look to clean and maintain your heat pump properly so it operates as efficiently as possible. Removing any dust, debris, or other blockages will help it continue to function optimally and prevent any excess strain on the unit, which could draw more power.

Adapt The Settings

You should set your heat pump so that it’s not always on the highest setting. Many modern heat pumps have timers, so you can set it to come on 15-30 minutes before you need it. This can save you a lot over the course of the year.

Turn It Off

Make sure you turn off the heat pump when you’re not using it. This will not only lower the running costs but help stop the heat pump from wearing out from overuse which will give you extra savings in the long run by protecting your investment. Learn about on and off cycles here.

Insulate Your Home

Insulating your home is a great way to save on energy bills because you’ll require less heating. It also makes your heat pump more effective as less energy is wasted.

People Also Ask (FAQ)

How many watts for a generator to run a heat pump?

Your generator will need to have a higher wattage than the combined wattage of all the appliances connected to it. Your generator should have at least 17,000 watts to run a heat pump without any issues.

How can I make my heat pump more efficient in the winter?

The best way to keep your heat pump running efficiently in winter is to maintain a consistent temperature on your thermostat. This will stop it from having to work harder at specific times and using more energy.

How many amps does a heat pump use?

A heat pump will draw between 8 and 24 amps on average, much less than other heating systems.

Does a heat pump use a lot of electricity?

Heat pumps do use a lot of electricity, but they are much more efficient than other heating systems.


Heat pumps are one of the most efficient ways to heat your home, but they still require a fair amount of energy. Hopefully, this article has helped you understand how much energy they use and how to determine what they may cost you. This should allow you to make accurate estimates and budget for the energy you’ll use each week, month, and year.

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.