Air Conditioning vs Central Heating: Running Costs Compared

Air Conditioning vs Central Heating: Running Costs Compared

With energy prices a constant concern for UK households, more people are asking whether air conditioning could be a cheaper way to heat their home. Here's a detailed breakdown of how the costs compare.

How Each System Works

Gas central heating burns natural gas in a boiler, which heats water. That hot water is pumped through radiators around your home. A modern condensing boiler is about 90-95% efficient, meaning for every £1 of gas, you get about 92p worth of heat.

Air conditioning (heat pump mode) uses electricity to move heat from outside to inside. It doesn't generate heat; it transfers it. A modern inverter AC unit has a Coefficient of Performance (COP) of 3-4, meaning for every £1 of electricity, you get £3-4 worth of heat.

The Numbers

Based on average UK energy prices (as of 2025):

| | Gas Central Heating | AC Heat Pump |

|---|---|---|

| Energy cost per kWh | ~6.8p (gas) | ~24.5p (electricity) |

| Efficiency | ~92% | ~350% (COP 3.5) |

| Effective cost per kWh of heat | ~7.4p | ~7p |

| Cost to heat a room for 1 hour | ~8-10p | ~7-10p |

| Annual cost (single room, moderate use) | £150-250 | £120-200 |

The key insight is that while electricity costs roughly 3.5 times more than gas per unit, heat pumps are 3.5 times more efficient. This means the running costs are remarkably similar.

When AC Heating Wins

Air conditioning is more cost-effective than central heating in several scenarios:

Heating a single room: If you only need to warm one room (a home office, for example), running the whole gas boiler and central heating system is wasteful. An AC unit heats just the room you're in.

Shoulder seasons: In autumn and spring, when you need a little warmth in the evening but not full central heating, an AC unit can warm a room quickly and cheaply without firing up the boiler.

Supplementary heating: Rooms that are always cold (conservatories, extensions, loft conversions) can be heated with AC more efficiently than trying to push more heat through an extended central heating system.

Homes without gas: If your property uses electric storage heaters or oil heating, AC heat pumps are almost certainly cheaper to run.

When Central Heating Wins

Gas central heating still has advantages in some situations:

Heating the whole house: If you need to heat every room, a gas boiler is more practical and often cheaper than running multiple AC units simultaneously.

Very cold weather: In sustained sub-zero temperatures, heat pump efficiency drops slightly, while gas boiler efficiency stays constant.

Hot water: Your gas boiler also heats your hot water. An AC unit only heats air.

The Hybrid Approach

Many of our customers use a hybrid approach: gas central heating as the base system for the whole house, with AC units in key rooms for additional comfort, cooling in summer, and efficient spot-heating when they don't want to run the whole system.

This gives you both options: whole-house heating when you need it, and efficient room-by-room control for the rest of the time.

The Bigger Picture

Beyond running costs, consider these factors:

Get a Quote

Curious about how much air conditioning would cost for your home? Request a quote and we'll arrange a survey for a fixed price. It takes under 2 minutes.