Whole House Heat Recovery (MVHR)

MVHR — Mechanical Ventilation with Heat Recovery — is a whole-house ventilation system that continuously supplies filtered fresh air to every room while recovering up to 93% of the heat from outgoing stale air. The result is a home that's consistently well-ventilated, free from condensation, and significantly cheaper to heat than one relying on background trickle vents alone.

We stock whole house heat recovery units from Vent-Axia, Zehnder, S&P, and Elta — covering properties from small apartments to large detached homes, with airflow rates from 63 m³/h up to 684 m³/h. All units are available with next day delivery, and our team is on hand to help with sizing and specifications.

What is an MVHR unit and how does it work?

An MVHR (Mechanical Ventilation with Heat Recovery) unit extracts warm, stale air from wet rooms — kitchens, bathrooms, utility rooms — and passes it through a heat exchanger. Incoming fresh air from outside is warmed by the outgoing air before being distributed to living rooms and bedrooms. The two airstreams never mix, so the supply air is always fresh. Efficiency ratings on the units we stock range from 78% up to 93%, meaning the vast majority of the heat that would otherwise be lost is recaptured.

Do I need an MVHR system in a new build?

Under UK Building Regulations Part F, all new residential builds must meet minimum ventilation standards. MVHR is increasingly the preferred solution for new builds and major renovations because it satisfies Part F requirements while also reducing heating demand — important for compliance with Part L (energy efficiency). If you're building to Passivhaus standard, MVHR is effectively essential.

What size MVHR unit do I need?

Sizing is based on the number of rooms and the total floor area of the property. As a rough guide: a 2–3 bedroom house typically requires a unit capable of 200–280 m³/h, while larger 4–5 bedroom homes need 350 m³/h or above. Zehnder's ComfoAir range and Vent-Axia's Sentinel Kinetic series both offer models across this range. If you're unsure, get in touch and we'll help you size correctly before you order.

What's the difference between MVHR and MEV?

MEV (Mechanical Extract Ventilation) only extracts air — it doesn't supply fresh air or recover heat. It's a lower-cost solution suited to properties where some natural air infiltration is expected, such as older homes. MVHR both supplies and extracts, with heat recovery, making it significantly more energy-efficient. For new builds and well-sealed properties, MVHR is the correct choice. For existing homes with some natural draughtiness, MEV may be sufficient — we stock both.

Which MVHR brand is best — Vent-Axia or Zehnder?

Both are industry-leading. Vent-Axia's Sentinel Kinetic range is widely used in UK new builds — robust, well-supported, and available at a range of price points from around £800 to £1,800. Zehnder's ComfoAir range sits at the premium end, with heat recovery efficiencies up to 93%, app-based control, and a reputation for ultra-quiet operation. For most domestic installations, Vent-Axia offers excellent value. For Passivhaus projects or where efficiency and noise levels are paramount, Zehnder is the benchmark.