How Much Does Air Con Cost To Run In The UK 2026 Guide
UK heat is on the rise. More homes now look to air con for cool air. But one big ask stays the same: how much will it cost to run?
In most UK homes, air con will cost from 20p to 70p per hour. The true cost will rest on unit size, rate per kWh, and how you use it.
Key Facts
- Cost per hour = kW × p per kWh
- Most home units cost 20p to 70p per hour
- High SEER = low run cost
- Split units cost less to run than port units
How To Work Out Your Run Cost
You need two facts:
- Your unit size in kW
- Your elec rate in p per kWh
The sum is:
kW × p per kWh = cost per hour
Quick Case
If your unit is 2.5 kW and your rate is 25p per kWh:
2.5 × 25p = 62.5p per hour
A 5 kW unit at the same rate:
5 × 25p = £1.25 per hour
What Can Change The Cost
1. Unit Type
Split wall units are more wise with power than most port units. They use in ver ter tech to shift load, not blast full time.
2. Unit Size
A big lounge needs more kW than a small bed room. Right size is key. Too big or too small can waste cash.
3. SEER Rate
SEER is a score of cool skill. High SEER means less power for the same cool air.
4. Home Insul
Good loft, wall seal, and glass will hold cool air in. Bad draft will let cool air out and hot air in.
5. Use Habits
Low set temp, long run time, and open doors will raise cost. Sleep mode and set time use can cut cost.
6. Elec Plan
Your rate per kWh is a big part of the sum. A low rate plan will cut cost at once.
Split vs Port Units
| Type | Run Cost | Upfront Cost | Long Term |
|---|---|---|---|
| Split Unit | Lower | High | Best value |
| Port Unit | Higher | Low | More per hour |
Split units cost more at the start, but tend to cost less each hour. Port units are cheap to buy, but use more power.
Four Ways To Cut Run Cost
- Use smart set – set time and temp with care.
- Clean filter – dust will slow air flow.
- Shut sun out – close blind in peak sun.
- Buy high SEER – best move for long term save.
Is Air Con High Cost In The UK
It is not free, but it is not as high as most fear. A new split unit, used with care, can cost the same as a wash or dry run for one hour.
For many homes, cool sleep and calm work in hot weeks is worth that cost.
FAQ
Is it less cost to leave it on all day
With new in ver ter units, low steady run can cost less than full blast cool from hot each time.
Does heat mode cost more
Heat mode can use more power. But as a heat pump, it can still beat old elec bar heat.
How much for 5 kW per hour
At 25p per kWh, it is about £1.25 per hour at full load.
Next Step
Pick the right size. Check SEER. Use smart set. With that, you can keep cool with no bill shock.