
How Much Does Air Conditioning Cost To Run in the UK? (Apr 2025 update)
Alexander BevanShare
Imagine on a sweltering summer day, you come home to find your living room feeling like an oven. You decide to turn on your 780W portable air conditioner to cool things down. But have you ever wondered how much this relief will cost you? With the current standard electricity tariff in the UK at 27.03p/kWh, running that air conditioner for just one hour will set you back approximately 21p. It’s a small price to pay for comfort, but let’s dive deeper into the overall costs of running air conditioning in the UK.
As the summer heat becomes increasingly intense, many households are prioritising air conditioning to stay cool and comfortable. However, with energy prices on the rise, understanding the running costs of air conditioning units is more crucial than ever. Whether you opt for a portable unit or a more traditional system, knowing what to expect can help you make informed decisions about your cooling solutions.
This article will explore the various factors that influence air conditioning costs, including initial purchasing and installation fees, ongoing operating expenses, and maintenance requirements. With a clearer understanding of these costs, you can choose the most efficient and economical cooling option for your home.

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How much does air conditioning cost to run UK?
Would it be cheaper to run aircon units that are portable, or should you stick to conventional AC? Let’s find out.
When determining the cost of running a central air cooling system, one has to consider three things:
● Buying and installation costs
● Operating costs
● Cost of Maintenance
Cost of buying and installing an AC
How much you spend on a centralised cooling system depends on the unit's cooling capacity and the number of rooms you want to cool. If you have been shopping for AC, you probably have heard of single-room or whole-house ACs.
Single Room / Split AC
Single-room AC, as the name suggests, provides cooling in one room. The most common type of single-room ACs is the split AC system. They are called split because they consist of an indoor unit that absorbs heat from the room and an outdoor unit that pumps cold air into the room.
These two units are connected using insulated pipes that are passed through a hole drilled through the walls.
Split ACs come in various sizes depending on how much energy they use to cool a room, often measured in BTUs. A small split AC unit rated 6000 BTUs is ideal for small rooms that are no bigger than 250 sq ft.
Expect to spend between £500 and £1500 for a split AC that will be used in one room. A double-room split AC will cost roughly £1500 to buy and £2500 to install, while a multi-room split AC can cost as much as £5000 to install.
Centralised or ducted AC units
Ducted ACs comprise a fixed AC unit that pumps cool air to various parts of a home or office through ducts that are connected to all rooms. The central AC unit must have a large power capacity to efficiently cool an entire home. As you've probably guessed, they can be expensive to install, ranging between £6000 and £9000 for a fully functioning unit.
Whoa! We haven’t touched on the cost of operating and maintaining these units.
Operating costs
How much electricity does a split or ducted AC unit need to cool a room or house in an hour, day, week, or month? Let’s find out.
A split AC unit can use about 480 watts an hour to effectively cool a room. A centrally ducted air conditioner can use 5000 watts an hour to cool an entire home.
Using a price rating of 24.86p/kWh:
Split AC running cost
480 watts/1000= = 0.48 kW
0.48kW x 1 hour = 0.48 kWh
0.48 x 0.27 = 0.129p
It will cost 0.129p to leave a split AC unit running for an hour.
Central / Ducted AC running costs
5000 watts/ 1000 = 5 kW
5kW x 1h = 5 kWh
5 x 0.27 = £1.35
A ducted AC will cost £1.35 to run for an hour
Aircon Running Cost Calculator Table (Hr to Month)
Cost/£ |
Hour |
Day(24 Hours) |
Week(7 Days) |
Month(30 Days) |
Split AC |
0.129p |
£3.09 |
£21.67 |
£92.8 |
Ducted AC |
£1.35p |
£32.4 |
£226.8 |
£972 |
Here's how much it costs you to run a split AC or a ducted AC in your home for an hour to a month. As you can see, ducted units can be expensive to run and will significantly increase your monthly energy bills. While split ACs are cost-effective for a single room, they can be pricey to run if they are installed in several rooms.

Try the Morris electricity calculator
You can quickly determine the electricity costs of any device using our calculator provided at the end of this article!
Cost of Maintenance
Like any electrical appliance, split and ducted ACs are prone to wear and tear with repeated use. Every once a year, these AC units need servicing to ensure they continue running efficiently. Also, factor in the cost of replacing faulty components like leaking duct pipes or AC refrigerants. This could easily attract an extra £20 to £180 to service your AC each year.
Air con running cost for portable air cooler
A portable air conditioner does cost less to run and maintain compared to conventional cooling systems. Take, for instance, a 990w portable air conditioner that can be used in a 20㎡. Here's how much it will cost to run a portable AC in your home or office.
First, the portable AC comes fully assembled and can be used straight out of the box. There is no need for expensive duct pipes or to hire someone to professionally install the unit. Now let's calculate the cost of running the unit.
Let's take a portable air conditioner that uses 990 watts of power.
990w/1000= 0.99kW
0.99kW x 1h = 0.99kWh
0.99 x 0.27 = 0.267p
It will cost 0.267p to run a portable air conditioner for an hour. This translates to £6.4 a day (24 hours) and £192.2 a month if used 24 hours a day, 7 days a week. Remember, this is a large portable air conditioner capable of cooling a room as large as 20㎡. And with its 9000 BTU capacity, it takes less time to cool a large room, which means less energy is used.
This portable air cooler should be enough to cool a garage, conservatory, kitchen or small studio apartment.
Although from our calculations, a split AC may seem cheaper, you have to consider the hidden costs of running one. There is an installation cost, which you do not need with a portable AC. In addition, a split AC unit remains stationary in one room and only provides cooling in that room. A portable air conditioner can be moved from room to room, which will be cheaper to run compared to installing a ducted air conditioning system.
Advantages of portable air conditioners
Running costs Air con running costs for portable air conditioners are lower compared to split and ducted AC units. Here are some more benefits of portable ACs that will convince you further.
Less noise
Another huge advantage of portable ACs is their low-noise operation. They produce noises as low as 70 dB, which is less disruptive. You can leave the portable air conditioner running all day and it will not disrupt your conversations or agitate a sleeping toddler.

Need a quiet, portable air conditioner?
Read our expert guide for top tips on choosing the best one—stay cool without the noise!
Easy installation
You do not need to hire an expert to install portable air conditioners. Most come fully assembled, and all you need to do is plug the unit into a power source and turn it on. You do not have to drill through walls to pass connecting pipes or install an expensive duct system to all the rooms in your house. Simply connect the window duct to easily drain water from the unit.
Compact design
Portable air conditioners have a slim design that will fit in any space. You can place them in corners when not in use and their aesthetic look will blend in with your decor. Since they stay on the ground, portable air conditioners do not block natural light from the window, unlike bulky mounted ACs that tend to take up window space.
Energy efficiency
Portable AC units are more energy efficient compared to split or ducted air conditioners. A typical tower air cooler with a 9000 BTU capacity only uses 990 watts of energy to cool a room as large as 20㎡. Accordingly, a 7000 btu portable air conditioner uses 780 watts of energy and is ideal for 10–15 square metres. Moreover, portable ACs are better than split ACs because they can be centrally placed in a room for efficient air circulation, which means low power usage.
Safe to use
Modern and stylish portable air conditioners now come with added safety features like an inbuilt child lock on the unit’s dashboard. This feature prevents a curious toddler from changing the settings on your AC while it runs.
Smart features
Having a portable AC with smart features makes it easy to remotely operate the unit for added efficiency. For instance, a compact air cooler with Wi-Fi allows you to monitor indoor temperatures, adjust fan speeds, or set running and standby times all with your smartphone. Smart features can help you run your portable air conditioner more efficiently and save on your monthly energy bills.
There are also portable ACs with in-built dehumidifiers. They cool a room by simultaneously filtering out hot air and humidity. Increased humidity can make hot weather feel more unbearable, and having a portable AC with an added dehumidifier comes in handy in such conditions.
Conclusion
How much does air conditioning cost to run UK? Well, it depends on whether you are going for modern or conventional cooling solutions. While conventional cooling options like split AC and ducted AC are effective in cooling, they do cost a lot to install, run, and maintain. Portable AC units are the future because they can be used straight from the box and come with smart features for added efficiency.
FAQs
Is air conditioning expensive to run?
Air con running costs depend on factors like the type and size of the AC, the size of the room to be cooled, and the cost of electricity. For example, a 9000 BTU AC using 900 watts of power could cost 0.27p to run for an hour, while a ducted air conditioner using 5000w will cost £1.35 (according to the current standard electricity tariff UK (27.03p/kWh) from 1 April to 30 June 2025. In addition, the bigger the room, the more power and time it takes for an air conditioner to cool that room, which can increase energy bills.
How much does portable aircon cost to run?
A portable air conditioner continuously drawing 780 watts of power uses 0.21p of electricity to run in an hour. The same unit would cost £5.064 to run for a day and £151.92 per month to run (based on current UK electricity price (27.03p/kWh) (1 April to 30 June 2025) if the appliance is constantly operating for 24 hours a day, 7 days a week. Most portable air conditioners come with added features, like inbuilt WiFi, which, when effectively used, can help drive air con running costs down.
How much does aircon cost to run on heat mode?
Air conditioners with an inbuilt heat pump can be used to warm a room on cold days. Ideally, a hot and cold AC consumes less power in heat mode compared to when it's in cooling mode. This should use less power, which means less energy costs when heating a room.


Alexander Bevan
This blog post writer is an expert in indoor climate and lighting solutions, with years of experience advising homeowners and businesses on optimising air quality, comfort, and energy efficiency. His well-researched, practical insights—backed by deep technical knowledge—help readers make informed decisions, ensuring trusted guidance for all their needs at Morris.
6 comments
Hello Mark,
Thanks for your question! The cost to run an air conditioner per hour in the UK depends on its power consumption and your electricity rate. Based on the current price cap of 27.03p/kWh, a typical 1kW portable air conditioner would cost around £0.27 per hour to run. Larger rooms or higher-powered units will increase costs, as the system works harder to cool the space. For best efficiency, ensure your unit’s BTU rating matches your room size. If you want, you can find a BTU calculator in the end of this post: https://www.morrisdirect.co.uk/blogs/advice-centre-portable-air-conditioning/the-ultimate-btu-calculator. Let us know if you’d like tips on cutting running costs!
Best,
Alexander
Hi Kev,
Thank you for your positive feedback! Yes, many split AC units come with heat pump functionality, allowing them to also heat a room effectively. This can be a cost-effective solution, especially in milder climates. When considering your options, it’s helpful to know how much an air conditioner costs to run per hour in the UK, as this can impact your overall expenses. If you want, you can share your room dimensions for tailored advice! If you have any more questions, feel free to ask!
Best,
Alexander
Thanks for the great article. My question is whether the split AC units can also heat a room and if this is a cost effective way?
Hi, I was wondering how much does an air conditioner cost to run per hour. I’ve got a portable unit and my bills seem high, but not sure if it’s normal. Also, does the size of the room effect it? Thanks!
Hello Gareth,
Thanks for your question! When it comes to whether is air conditioning expensive to run, it really depends on the type of unit you choose and how you use it. Portable air conditioners, as mentioned in the article, are generally more cost-effective to run compared to split or ducted systems, especially if you’re only cooling one room at a time. For example, a 9000 BTU portable AC costs around 0.24p per hour to run, which is much lower than a ducted system (£1.24/hour).
Investing in a smart portable AC with Wi-Fi can definitely help save on energy costs in the long run. Features like remote control and scheduling allow you to optimise usage, ensuring the unit only runs when needed. This can reduce unnecessary energy consumption and keep your bills lower.
If you’re looking for an affordable and efficient cooling solution, a portable AC is a great choice—just be mindful of usage patterns to keep costs down. Let me know if you have more questions!
Cheers,
Alexander