Category - Air Conditioning
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Will Scholfield, Engineer

31 Jan : Updated 15 Apr ● 11 min read

How much does air conditioning cost to run?

The cost of running an air conditioning system is determined by several different factors, not least the type of air conditioning unit, its output and the size and layout of the property. 

How to work out the cost of running an air conditioner

How much does it cost?

The cost of running an air conditioning unit will vary exponentially depending on the level of output (wattage) and the size of the room. The most accurate way to know how much it will cost you is to ask a professional for an air conditioning quote before installing air conditioning in your home.

But for a rough idea of how much it might cost per hour, input the wattage of your chosen AC unit and '1' (hour) into this electricity cost calculator.

On average, however, here’s how much, based on the current energy price cap cost (April 2022) some of our most popular Samsung air conditioning units and Bosch air conditioning units cost to run per hour:

Air Conditioning Unit

Cost to run per hour

Samsung CEBU 2.5kW

£0.70 p/h

Samsung CEBU 3.5kW

£0.98 p/h

Samsung CEBU 5.0kW

£1.40 p/h

Samsung CEBU 6.5kW

£1.82 p/h

Bosch Climate 3000i 2.6kw

£0.73 p/h

Bosch Climate 3000i 3.5kW

£0.98 p/h

Bosch Climate 3000i 5.3kW

£1.48 p/h

Bosch Climate 3000i 7.0kW

£1.96 p/h

Factors that influence the cost?

Type of air conditioning system

There are different types of home air conditioning units, and which type you choose will affect your electricity bill.

Portable air conditioning units are a relatively easy option and a good choice for the home. The versatility of portable air conditioners means they can be moved from room to room, floor to floor, hassle-free, so you can feel the benefit where you need it most. There is no installation cost either - just plug in and you’re ready to go.

The disadvantage to these types of units is their performance. They won't have full capability to reduce the temperature accurately. They may be used more for taking the edge off and making the room more comfortable. 

Portable air conditioners are also among the most expensive AC units to run, and long term use is likely to cause an unwelcome spike in your electricity bills.

Central or 'ducted' air conditioning systems require professional installation and rely on ducts to circulate cool air (or hot air) around a building. The air is dispersed by a central unit and swept through the ducts by a fan system.

This type of air conditioning system usually makes the most sense in smaller commercial spaces. The more the air is required to travel through ducting, the more air is lost, and the more it is required to repeat its efforts. From this perspective, it is not the most energy-efficient unit, and running costs may be high. This is usually the most common in new buildings as the ducting is not something easily retro fit into a building. 

Split air conditioning systems rely on wall or ceiling mounted units to control the flow and temperature of the air in different parts of the property. The precise control of this AC unit means you can cool or heat specifically the room(s) required without wasting money directing air to areas not in use. 

These are the most popular in a lot of domestic scenarios in the uk and offer easy installation and good levels of control and performance. 

If you can manage the initial installation cost, split or multi-split air conditioners are an economical, long term air conditioning solution. 

The age of your AC unit

The efficiency of air conditioning units depletes over time, and as this occurs, air conditioning running costs are likely to increase as the unit is struggling to maintain maximum output. 

The system output

A clever way to keep the air conditioning running costs to their minimum is to select the system with the correct output for your needs. The 'output' of an aircon unit determines the power of your climate control system.

If you choose a system with too weak an output, the cost to run will be unnecessarily high because you are forced to leave it on longer to compensate for this reduced power.

Alternatively, if an air conditioner with an overzealous output utilises more energy than you need,  it can lead to air conditioning running costs that are above and beyond what you actually use.

The number of hours you are running your system for

The more you use it, the more hours' energy you are paying for.

Use the AC to get you through the heat of the day but if you can get away with a fan in the morning or at night, when it is generally cooler, try that.

Reason for use: heating or cooling

Generally speaking, it will cost more to use an air conditioning system for heating than for cooling. This is because of the heat energy required to warm up the air inside your home.

Your system’s efficiency

The efficiency of your air conditioner will impact your electricity costs. The more efficient air conditioners utilise less energy to cool or heat the space, generate less wasted air and, therefore, less wasted energy.

Air conditioning units with limited energy efficiency will have to work harder - generating more energy and costing more money - to achieve the same result. A flaw in any part of the system: a blocked filter or damaged ducting could reduce the efficiency of the whole unit.

Read: Energy Efficiency Ratio in air conditioners

How well-insulated is your property

The better insulated your property is, the lower your air conditioning cost is likely to be. This is because the air inside your home can be affected by the temperature outside.

If your property is well-insulated, the external temperature will have less effect, meaning you can maintain the desired internal temperature constant for longer - without tweaking that costly climate control.

A property with less effective insulation will surrender control more quickly. If it is hot outside, the cool air inside will warm up, and the air conditioning system will have to fight against nature to maintain your desired internal temperature.

Servicing and maintenance

An air conditioning unit is recommended to be checked once a year to ensure that it is still in good working order. This will also highlight any parts which need to be repaired or replaced, which will save damage to other components and preserve the system as a whole.

It is also good practice to ensure any vents, pipes and filters are kept clean. Over time these can become blocked, demanding a more significant surge in power from your AC unit, and increasing air conditioning costs.

System controls

It is easy to be put off by the initial cost of an air conditioning unit with costly, extra system controls, and some of these seem to have limited use, such as a night light. However, some of these other added extras may reduce running costs and so be worth the additional investment.

Choosing an air conditioning system with timer control will help to ensure that your AC unit is only running when it needs to be or just in time for you to get home at the end of the day. Air conditioning units with maximum zone control will also have a positive, long term impact on the cost to run by enabling you to be precise and avoid cooling a larger area unnecessarily.

Perhaps the most beneficial is a remote control app or a smart thermostat which allows you to control your unit from afar. This is ideal if you forget to switch off your AC unit before you leave or if you decide to stay out longer so as not to run an air conditioner in an empty house accidentally.

System features

The more elaborate air conditioning systems include a range of additional features and capabilities, including cooling, heating, dehumidifying, air purifying, and automatic modes.

The more features your air-con offers, the greater the cost to run. However, you are not just paying to run an air conditioner and beat the heat, but also for a warmer home in the winter months and purer, cleaner air all year round.

How to reduce the cost?

Couple the air conditioning unit with solar

A good idea would be to couple an air conditioning unit with Solar, as they will use electric to function and don't require any connections once installed. This is a cost effective and green way to use your AC unit, ideal for those at home offices in the garden as they can be used for heating in the winter and cooling in the summer.

Seal the windows

Open windows leak cool air, which means the air conditioning is forced to work harder to replace the lost air. Sealing the windows and checking for cracks will keep the cooled air contained and reduce the strain on the air conditioner.

Close the vents in any unused rooms

If vents are blowing air into unused rooms, you pay for energy that is not being used. Close vents in new rooms and focus on climate control in your most-used spaces.

Invest in a smart thermostat

A smart thermostat will cut energy usage by controlling the temperature while you are out or asleep. Some of these can be programmed in advance or taught your preferences, whilst others use an app to give you complete control of your air conditioning wherever you are.

Keep up with the maintenance schedule

Keeping up to date with the maintenance will save you a lot of grief and expense. The cost to run air conditioning will increase if components are damaged since the unit is forced to work harder.

A reliable air conditioning contractor should check and clean coils, replace damaged ducting, and test connections to prevent wasted energy.

Clean your air conditioner

Cleaning or replacing blocked filters is a simple thing you can do yourself, which may reduce the energy consumption of your air conditioner by as much as 15%. The filter should be checked every few months, but they are likely to clog faster if you have long-haired pets.

How to choose an energy-efficient air conditioner

This really depends on how much you plan to use it and the size and layout of the space you hope to keep cool. Air conditioning is not great for the environment, and it can work out expensive too. Spending a little more on the most efficient solution for your needs will work out better for your wallet and the planet. 

Use our specially designed calculator to receive an air conditioning quote for the unit size required.

The main thing to consider is the size of your space, and select an air conditioning unit with the BTU (British Thermal Unit) value to match. An easy way to figure this out is to calculate the square feet of your space and multiply by 25BTU.

Here is a BTU Calculator to help you out.


How often should I have my air conditioning serviced?

You should service your air conditioning at least once a year. If you run your air conditioner every day, you might consider having it serviced two or three times yearly.

Does turning your AC up during the day save money?

Investing in a programmable thermostat to increase air conditioning to reach a constant, comfortable level can save money. Turning it off, then arriving home and turning it straight up to maximum for a quick cool-down is neither energy nor cost-efficient.

Is it cheaper to run AC all the time?

No. Running air conditioning every day gradually burns through more energy, costing you more money and the planet more of its valuable fossil fuels.

What type of air conditioning is the most cost-effective?

A portable air conditioner is the least expensive to buy and a good, quick fix for a short while. However, this will quickly become expensive to run and won't be the best performing unit

A split air conditioner, whilst more expensive to set up, is the most cost-effective option in the long run and one of the better performing. Split air conditioning can save energy by only cooling the air in the desired space and more precisely.

This is increasingly cost-effective when partnered with a programmable thermostat or app, which will let you control your split air AC in advance and from afar, thereby reducing wasted energy and money. 

We also have a comprehensive guide on Wall Mounted Air Conditioning vs Portable Air Conditioning Units to help you make the right choice.

Final thoughts

Air conditioning will cost you money - there is no way around it. But there are ways you can control and even reduce the cost.

Take the time to figure out which unit is the right one for you and your space. Check your insulation, and when you add an AC unit to your family, be sure to keep it clean! Also, keep in mind that air conditioning shouldn't replace a fan; they work better together!

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