Is Aircon Cheaper to Run than Central Heating?

With electricity and gas prices fluctuating, more UK households are asking whether air conditioning in heating mode can work out cheaper than using a gas or electric central heating system. Modern air conditioners are in fact heat pumps, capable of delivering heating as well as cooling. The question is whether they can provide a cost-effective alternative for everyday use in homes across Hampshire, Berkshire, Surrey, and Oxfordshire.

Understanding How Aircon Heats

Air conditioning systems with heat pump technology transfer heat from outside air into the home. They use electricity to power the compressor and fans, but the heat delivered is greater than the electricity consumed. This is measured as the Coefficient of Performance (COP).

For example, if a system has a COP of 4, it produces 4 kWh of heat for every 1 kWh of electricity used. By comparison, electric resistance heating (like panel heaters) has a COP of 1, producing only 1 kWh of heat per 1 kWh of electricity.

Comparing Running Costs

To compare air conditioning with central heating, we need to look at typical costs as of 2025.

• Electricity price: About 28p per kWh
• Gas price: About 7p per kWh

Gas Boiler

A modern condensing boiler may achieve 90 percent efficiency. That means for every 1 kWh of gas, 0.9 kWh of heat is delivered. Heating 1 kWh of space therefore costs about 7.8p.

Air Conditioning in Heating Mode

If an air conditioner achieves a COP of 4, then 1 kWh of electricity at 28p produces 4 kWh of heat. That makes the effective cost 7p per kWh of heat.

Electric Panel Heater

1 kWh of electricity produces 1 kWh of heat. Cost per kWh of heat: 28p.

From this comparison, it is clear that air conditioning in heating mode is competitive with gas boilers and dramatically cheaper than electric resistance heating.

Real-World Example

A homeowner in Basingstoke heats their garden office using a 2.5 kW split system. On a winter day, the unit consumes about 0.7 kW of electricity per hour. Over an 8-hour workday, this costs about £1.60. Heating the same space with an electric heater would cost more than £5 for the day.

In Guildford, a family uses their air conditioning system to heat bedrooms overnight. Compared with running the gas central heating for the whole house, they only heat the rooms they use. Their energy bills have dropped because zoning avoids waste.

The Role of Zoning

Central heating systems warm the entire house. Air conditioning systems allow zoning, so you can heat only the spaces you need. For households in Reading or Winchester, this often makes the difference between affordable and wasteful heating.

Examples of zoning benefits:

• Heating just the master bedroom at night.
• Heating a home office during work hours.
• Switching off unused rooms without affecting comfort.

Seasonal Use

Air conditioning is not always the cheapest option in the depths of winter, when outside temperatures fall very low. Gas boilers can still deliver reliable whole-house heating. However, in autumn and spring, when mild weather means only a few rooms need warmth, air conditioning systems provide highly efficient and cost-effective heating.

Environmental Impact

Because air conditioning in heat pump mode delivers more heat than the energy it consumes, it has a lower carbon footprint than older electric heating systems. It also aligns with UK Government plans to phase out reliance on fossil fuels and promote low-carbon heating.

For homeowners in Oxfordshire, where many properties are listed or constrained in terms of retrofitting, adding split systems can provide both comfort and compliance with future energy targets.

Financial Perspective

• Gas central heating: Cheapest for whole-house heating during cold weather.
• Air conditioning heat pump: Cheapest for targeted heating and competitive with gas for smaller spaces.
• Electric resistance heating: The most expensive option.

Making the Right Choice

The decision between air conditioning and central heating depends on your priorities.

• If you want to heat your entire home during winter, gas central heating remains cost-effective.
• If you want to heat specific rooms, such as a loft conversion, bedroom, or home office, air conditioning is usually cheaper.
• If you currently use electric heaters, switching to air conditioning in heat pump mode will save significant money.

Installers like ClimateWorks advise homeowners across Hampshire, Berkshire, Surrey, and Oxfordshire on how to design systems that reduce heating costs without sacrificing comfort.

Looking Ahead

As more homes transition towards electrification, the role of heat pumps will only grow. Air conditioning is already delivering affordable heating and cooling for thousands of UK households. With careful system design and realistic use, it can be one of the most cost-effective ways to keep homes comfortable year-round.

References

• Ofgem, Energy Price Trends 2025 – Ofgem
• UK Government, Heat Pump Ready Programme – GOV.UK
• Energy Saving Trust, Air Source Heat Pumps – Energy Saving Trust
• Mitsubishi Electric UK, Heating and Cooling with Air Conditioning – Mitsubishi Electric

About the Author

Dr. Julian Carter – Technical & Compliance Director, ClimateWorks

Dr. Julian Carter is a recognised specialist in building services engineering with over 25 years of experience in ventilation, refrigeration, and air conditioning. As Technical & Compliance Director at ClimateWorks, he advises on best practice for system design, installation, and maintenance across residential and commercial projects in Hampshire, Berkshire, Surrey, and Oxfordshire. He also lectures part-time at a leading UK university, sharing his expertise with the next generation of engineers.

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