Are Heat Recovery Systems Expensive to Run?

Heat recovery systems, or Mechanical Ventilation with Heat Recovery (MVHR), are designed to reduce energy waste and maintain a healthy indoor environment. But one of the most common questions from homeowners across Hampshire, Berkshire, Surrey, and Oxfordshire is: how much does it actually cost to run?

The answer is reassuring. MVHR systems are very inexpensive to run. In most homes, they cost less than £5 a month to operate, while saving far more in heating energy than they consume in electricity.

Understanding Running Costs

An MVHR system works by using two low-energy fans to circulate air through the property. One fan draws in fresh air from outside, while the other extracts stale air from kitchens and bathrooms. Inside the heat exchanger, up to 90% of the warmth from the outgoing air is transferred to the incoming fresh air.

These fans use very little electricity. A typical household system runs continuously at low speed, consuming around 20 to 40 watts per hour, similar to a small light bulb.

Based on the current UK electricity price of 28p per kWh (Ofgem, 2025), this equates to:

• Around £40 to £60 per year for a medium-sized home
• Or roughly £3 to £5 per month

When compared to the heating energy saved, this cost is extremely low.

How Heat Recovery Systems Save Energy

By recycling warmth that would otherwise be lost through extraction or open windows, an MVHR system reduces the need for central heating.

Studies show households can save up to 30% on heating bills depending on insulation quality and occupancy habits. In practice, this means the energy saved far exceeds the small amount consumed by the system.

For example:

• In Basingstoke, a three-bedroom home reduced annual heating costs by £180 after installing MVHR.
• A property in Reading reported running costs of just £4 per month while keeping rooms consistently warm.
• In Guildford, an airtight new build saved approximately 25% in total heating demand each year.

These results reflect what happens when MVHR is properly installed and balanced.

Factors That Influence Running Costs

Although all systems operate efficiently, several factors affect real-world running costs:

• System size – larger homes need slightly more airflow and fan power.
• Filter cleanliness – clogged filters make fans work harder and consume more energy.
• Airflow settings – running at unnecessarily high speeds increases consumption.
• Insulation quality – poor insulation reduces overall efficiency gains.

Regular maintenance and correct system configuration ensure the lowest possible running cost.

Energy Efficiency in Detail

A well-installed MVHR system achieves an energy recovery efficiency of 85–90%. For every kilowatt of heat energy extracted, around 0.9 kW is returned to the home.

This is why MVHR is classed as an energy-saving measure under Building Regulations Part F and Part L. It helps new homes meet mandatory energy performance targets without relying on more heating capacity.

Environmental Impact

By reducing the need to generate new heat, a heat recovery system lowers carbon emissions. The average household in southern England could save around 300 kg of CO₂ each year by using MVHR instead of traditional extraction systems.

These savings contribute directly to the UK’s net-zero targets for housing efficiency.

Maintenance Costs

Running costs remain low as long as the system is maintained:

• Filters should be cleaned or replaced every six months.
• A professional service once a year keeps fans and heat exchangers operating efficiently.

Maintenance costs are usually £100 to £150 per visit, which keeps the system in peak condition.

All electrical work must be installed and certificated by a qualified electrician. This ensures both compliance and energy performance remain optimal.

Common Misconceptions

Some homeowners believe MVHR is costly because it runs 24 hours a day. In reality, it uses far less power than people think. Turning it off to save electricity can cause damp, condensation, and poor air quality, which may end up costing more to fix.

Continuous low-speed operation is both more efficient and better for the health of the building.

Value Over Time

When viewed over ten years, an MVHR system typically saves more in heating energy than it costs to run and maintain.

A small additional electricity cost each month leads to:

• Lower heating bills
• Cleaner, filtered air
• Balanced humidity levels
• Protection against mould and condensation damage

This makes it one of the most cost-effective energy-saving systems available for UK homes.

Why Professional Installation Matters

To keep operating costs low, the system must be correctly sized and balanced during installation. An undersized or poorly designed system may need to run harder, increasing electricity use unnecessarily.

At ClimateWorks, we install MVHR systems across Hampshire, Berkshire, Surrey, and Oxfordshire. Each system is designed for quiet, low-energy operation and full compliance with Building Regulations.

References

• Ofgem – Domestic Electricity Prices
• UK Government – Building Regulations Part F
• Energy Saving Trust – Home Ventilation

Author Bio

Dr Julian Carter is Technical and Compliance Director at ClimateWorks. With more than 25 years of experience in air conditioning, refrigeration, and ventilation, Julian has worked on projects across Hampshire, Berkshire, Surrey, and Oxfordshire. He also teaches as a visiting professor at a UK university, specialising in low-energy building design and mechanical ventilation systems. His expertise helps ensure ClimateWorks installations are efficient, compliant, and designed for long-term reliability.

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