Set the sliders to your own tariffs and see the real figure, next to a portable unit, a dehumidifier and a gas boiler.
Set your own tariffs and how long it runs. See what air con actually costs to run, next to the alternatives.
Want the full picture? Read what it really costs to run, or build your install price.
Three things decide what it costs you: how big the room is, how hard the unit has to work to hold the temperature you've asked for, and what you pay per unit of electricity. That last one is why this page asks for your own tariff rather than assuming a national average. A unit that's comfortably sized for the room spends most of its time ticking over rather than working flat out, and that's where the low figures on this page come from.
An air conditioner doesn't make cold air, it moves heat out of the room, and moving heat takes far less electricity than making it. That's the same reason it's efficient in reverse: for every £1 of electricity it puts out around £4.60 of heat. The unit we fit is A+++ rated and runs at 17.5 dB(A) on its lowest setting, which is quieter than a mouse's squeak.
This is the question we get asked most in a heatwave. Overnight is usually the cheapest time to run it, because the outside temperature has dropped and the unit has less work to do to hold the room where you want it. The eight hour figure on this page is there for exactly that reason: it's the number that matters if what you actually want is to sleep.
A fan is cheaper to run, but a fan doesn't lower the temperature of the room, it just moves the air around. A portable plug-in unit does cool, but it's less efficient than a fitted split system and it has to sit in the room with a hose out of the window. A dehumidifier takes moisture out but doesn't cool. The comparison above puts all of them side by side on your own tariff, so you can see the difference rather than take our word for it.
You might also want to read the full running-costs guide, or build your install price.