Is Air Con Expensive to Run in the UK?

Air conditioning is becoming more common in UK homes, particularly in areas like Hampshire, Berkshire, Surrey, and Oxfordshire. Yet one of the biggest concerns homeowners raise before installing is running cost. With energy prices having risen in recent years, it’s a fair question: is air conditioning expensive to run in the UK?

What Determines the Running Cost of Air Conditioning?

Several factors affect how much you pay when you switch on your system:

• System size and capacity: A small 2.5 kW unit for a bedroom uses less energy than a 7 kW system for a kitchen diner.
• Efficiency rating (SEER/SCOP): Modern inverter systems adjust output to demand, consuming less electricity.
• Electricity tariffs: As of 2025, UK electricity prices average 28p per kWh.
• Usage hours: Most UK homeowners use air conditioning for a few hours in the evening or overnight, not continuously.
• Building design: Insulation, glazing, and shading directly influence energy use.

Typical Hourly Running Costs

Based on current tariffs, average consumption looks like this:

• 2.5 kW bedroom unit: 0.7 kW per hour = 20p
• 5 kW family room system: 1.5 kW per hour = 40p
• 7 kW kitchen diner system: 2.2 kW per hour = 60p

Because inverter compressors rarely run at full load continuously, actual costs are often 30–40 percent lower than headline figures.

Daily and Monthly Scenarios

• A bedroom unit running for 8 hours overnight: £1.60
• A family space unit running for 5 hours in the evening: £2.00
• Running one large unit all day (24 hours): £14.40

For a typical household in Reading or Basingstoke, using two units for 3 hours each evening, the monthly cost might be under £50.

Comparison with Other Appliances

To put this into perspective:

• A tumble dryer cycle: £1.40
• Electric oven for 2 hours: 84p
• Dishwasher cycle: 70p

Air conditioning is therefore not disproportionately expensive compared with everyday appliances.

Air Conditioning as a Heating Option

Air conditioning systems double as heat pumps. In winter, they can be used for heating, often at lower cost than electric panel heaters.

For example, heating a garden office in Guildford with a 2.5 kW split system might cost £1.60 for an 8-hour day, compared with £5 for an electric heater. This versatility adds to the value of running air conditioning year-round.

Regional Demand and Perception

In Winchester and Oxford, where more homeowners are investing in comfort systems, demand is rising despite concerns about cost. Many are discovering that with correct system design and zoning, bills remain manageable.

Zoning ensures that only the rooms in use are conditioned. Instead of heating or cooling the whole house, you only pay for comfort where and when you need it.

Practical Steps to Keep Costs Low

• Set your thermostat at 21–22°C rather than very low or high extremes.
• Clean or replace filters regularly to maintain airflow.
• Use blinds or shading to reduce solar gain.
• Choose modern inverter-driven units with high efficiency ratings.
• Work with a trusted installer like ClimateWorks to size and configure systems properly.

The Balance Between Cost and Comfort

For most UK households, air conditioning is not expensive to run when used sensibly. The key lies in understanding usage patterns, selecting the right system, and making small changes to improve efficiency.

Compared with the value delivered — cooling in summer, heating in winter, cleaner air, and better humidity control — the running costs are proportionate. Homeowners across Hampshire, Berkshire, Surrey, and Oxfordshire increasingly see it as a practical investment rather than a luxury.

References

• Ofgem, Electricity Price Trends 2025 – Ofgem
• Energy Saving Trust, Household Appliance Energy Use – Energy Saving Trust
• UK Government, Energy Performance of Buildings Regulations – GOV.UK
• Mitsubishi Electric, Residential 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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