How much does it cost to run air conditioning?
A modern air conditioner that heats and cools usually costs pennies an hour to run, not pounds. At this winter's average electricity price of 26.32p per kWh, a typical unit warming a living room on a cold day costs around 20p to 30p an hour while it works hard, and less once the room is warm. Below we show the maths, so you can work out the cost for your own home, and compare it with gas and plug-in electric heaters.
What you pay for electricity this winter
The energy price cap, set by Ofgem, decides the most a supplier can charge per unit on a standard variable tariff. It changes every three months. From 1 October to 31 December 2026 the average figures for England, Scotland and Wales, paying by Direct Debit, are:
If you are on a fixed tariff, use the unit rate on your own bill instead. The next price cap change is on 1 January 2027.
Why air conditioning heats so cheaply
An air conditioner that heats is an air to air heat pump. It does not make heat from electricity the way a fan heater does. It uses electricity to move heat from the outside air into your room, so you get several units of heat for every unit of electricity you pay for.
How many units you get is measured by a number called SCOP for heating and SEER for cooling. The higher the number, the cheaper it is to run. Modern units are commonly rated at a SCOP of around 4, which means about 4 kWh of heat for every 1 kWh of electricity across a typical heating season.
Plug-in electric heater
- 1 kWh of electricity gives 1 kWh of heat
- 26.32p for every kWh of heat
- Heats only, no cooling
Air conditioning that heats (SCOP 4)
- 1 kWh of electricity gives about 4 kWh of heat
- About 6.6p for every kWh of heat
- Heats in winter, cools in summer
Working out the cost of heating a room
Here is a worked example. Say your living room needs 2 kW of heat to stay warm on a cold evening, and the heating runs for 8 hours. That is 16 kWh of heat.
- Heat needed: 2 kW x 8 hours = **16 kWh of heat**.
- Electricity used by the air conditioner: 16 kWh / 4 (its SCOP) = **4 kWh**.
- Cost: 4 kWh x 26.32p = **about £1.05 for the day**.
- Over 30 days of that use: **about £32 a month** for that room.
The same 16 kWh of heat from a plug-in electric heater would cost about £4.21 a day. From a gas boiler running at 90% efficiency it would be about 17.8 kWh of gas, around £1.42 a day. These are worked examples, not quotes: your own figure depends on the size of the room, how well it holds its heat and how warm you like it.
The cost of one unit of heat
Based on 26.32p per kWh and efficiencies between 3 and 5. Gas from a 90% efficient boiler works out at about 8.9p per kWh of heat.
So a good air to air system can heat a room for less than a gas boiler and for a quarter or less of the cost of plug-in electric heating, at today's prices.
What about cooling?
Cooling works the same way in reverse, taking heat out of the room and sending it outside. Cooling efficiency (SEER) is often higher than heating efficiency, so keeping a room cool in summer is usually cheaper than heating it in winter.
As an example, if a unit gives 3.5 kW of cooling and uses 1 kWh of electricity an hour at full power, that hour costs about 26p. Most of the time it runs well below full power once the room has cooled, so the real cost is usually lower.
Good to know
Efficiency drops a little on the coldest days, because there is less heat in the outside air to collect. SCOP is an average across the whole season, which already allows for colder spells.
How to keep running costs down
- Choose the right size unit for the room. Too small and it runs flat out; too big and it switches on and off.
- Set a steady temperature and leave it, rather than turning it right up then off again.
- Keep doors closed in the rooms you are heating or cooling.
- Clean the filters regularly and have the system serviced every year.
- Use the timer or app so it only runs when you need it.
At ArcticNord every installation starts with a room by room survey, so the unit is sized for your room, and you get a fixed written quote before any work begins. We also service and maintain systems, including ones we did not install.
Book your free room by room survey with ArcticNord. We cover Nottinghamshire, Leicestershire, Derbyshire, South Yorkshire and West Yorkshire.
Get an AC / Heat Pump QuoteQuestions people ask
Is it cheaper to heat with air conditioning or gas?
At the October to December 2026 price cap, a unit with a SCOP of 4 produces heat for about 6.6p per kWh, compared with about 8.9p per kWh of heat from a 90% efficient gas boiler. So it can be cheaper, depending on how efficient your unit is and how you use it.
How much does it cost to run air conditioning for an hour?
It depends on how hard it is working. As a guide, a unit using 1 kWh of electricity in an hour costs about 26p at 26.32p per kWh. Once the room reaches the set temperature, most units use much less than that.
Does air conditioning use a lot of electricity?
Less than most people expect, because it moves heat rather than making it. A modern unit gives about 3 to 5 kWh of heating or cooling for each kWh of electricity it uses.
Will the price change?
The price cap is reviewed every three months, and the next change is on 1 January 2027. To redo the maths, swap 26.32p for the unit rate on your own bill.
Does leaving it on all day cost more?
Often it costs about the same or less to keep a steady temperature than to heat a cold room from scratch each time. A timer that runs it when you are home is usually the best balance.
Where these facts come from
- Ofgem: price cap 1 October to 31 December 2026. Electricity 26.32p per kWh, standing charge 54.83p a day, no VAT from 1 October 2026 to 31 M…
- Fuse Energy: temporary 0% VAT on domestic electricity, 1 October 2026 to 31 March 2027; gas stays at 5%
- Energy Saving Trust: air to air heat pumps heat and cool using indoor and outdoor units (updated 20 October 2026)
- Midea UK price list 2025: example SCOP 4.1 to 4.2 and SEER 6.4 to 7.6 on the Breezeless E range