What is MVHR, and do you need it? 

What is MVHR?

MVHR stands for Mechanical Ventilation with Heat Recovery, also commonly referred to as HRV (Heat Recovery Ventilation). It is a whole-house system that runs continuously, drawing fresh air in from outside while expelling stale air from inside. As it does this, it transfers heat from the outgoing air to the incoming supply. You ventilate without losing warmth.

The key component is a heat exchanger. Warm stale air from bathrooms, kitchens and living spaces passes through it on the way out. Fresh cool air from outside passes through at the same time, picking up that heat before it reaches your rooms. The two airstreams never mix.

ProAir manufactures the PA700LI at our Galway facility, and an independent SAP Appendix Q PCDB Certification confirms up to 95% heat-exchange efficiency, with one unit covering homes up to 270 square metres.

The benefits of heat recovery ventilation

1. Healthier air – MVHR filters incoming air before it reaches your rooms, removing pollen, dust, and traffic pollutants. CO2 levels stay lower across the home. For families with allergies or asthma, the difference is noticeable relatively quickly.
2. Lower energy bills – Recovering the vast majority  of the heat from outgoing air means your boiler or heat pump has to do less work to maintain comfort. In a well-insulated Irish home, ventilation is one of the main sources of heat loss. MVHR addresses that directly.
3. No condensation or mould – Condensation and mould are symptoms of excess moisture in the air. MVHR continuously removes humid air from wet rooms and living spaces, keeping humidity at a healthy level throughout the year.
4. Compliance with Irish building regulations – Part F of the Irish Building Regulations sets minimum ventilation standards for new dwellings. For modern airtight homes, MVHR is the most practical way to satisfy those requirements. ProAir’s design team has been working with the Irish regulations for over 30 years and provides full specification support on every project.

What the EU 2030 buildings directive means for Irish homeowners

The Recast Energy Performance of Buildings Directive, which entered into force in May 2024, requires all new buildings in the EU to be zero-emission from 1 January 2030. For residential buildings, it also requires a 16% reduction in average primary energy use by 2030 and 20 to 22% by 2035. 

Ventilation heat loss is one of the main contributors to primary energy demand in modern airtight homes. Recovering most of that otherwise lost heat , as the PA700LI does, directly reduces the primary energy figure that will define your home’s performance rating.

Ireland must transpose the directive into national law by May 2026, with updated building regulations to follow. Homes being planned today will be built and sold into a market shaped by those standards.

ProAir’s design team works with architects, engineers, and self-builders to ensure every system is compliant with current requirements and positioned for what is coming. To understand what the 2030 standards mean for your project, speak to our team.

MVHR vs MEV and Extractor Fans

Traditional extractor fans work adequately in older, draughty homes where natural infiltration fills the ventilation gaps. In modern airtight homes, a continuous whole-house ventilation strategy is required. In Ireland, the main mechanical options are intermittent extractor fans, Mechanical Extract Ventilation (MEV), and Mechanical Ventilation with Heat Recovery (MVHR).

The table below sets out the key differences: