MVHR (Mechanical Ventilation with Heat Recovery) units that supply filtered fresh air while recovering up to 90% of the energy from extracted stale air.
Heat recovery ventilation (MVHR) is a ducted system that continuously extracts stale air from kitchens, bathrooms and laundries and supplies filtered fresh air to living areas and bedrooms, transferring up to 90% of the outgoing heat to the incoming air. In Australia it suits airtight new builds, Passivhaus projects and allergy-sensitive households. AHHAC supplies and installs Zehnder, Stiebel Eltron, Mitsubishi and Brink units, sized to the home's air volume and running under 25 dB.
Reviewed by the AHHAC Technical Team — licensed plumbers & hydronic engineers, NSW Lic 262528C.How we write & review
MVHR is a non-negotiable for tight-built modern homes — Passivhaus, certified high-performance builds, and any home with a high-quality envelope.
We supply Zehnder ComfoAir, Stiebel Eltron LWZ, Mitsubishi Lossnay and Brink Renovent. Sizing is critical — undersized units short-cycle, oversized units waste energy.
Heat recovery ventilation only performs in a home that is reasonably airtight. In a draughty house, air leaks straight past the system and the unit just adds fan noise and running cost. That is why most of our MVHR work is in new builds and deep renovations, and why the important decisions happen early, while the frame is still open.
At commissioning we measure and balance the airflow at every supply and extract valve so the home is neither pressurised nor depressurised. Skipping that step is the most common fault we find on systems installed by others: one room stuffy, another whistling. After handover the main job is filter changes, which keep the F7 and G4 filters doing their work and stop the fans labouring. Most controllers remind you when they are due.
MVHR handles fresh air, not heating. In a well-sealed home it pairs naturally with hydronic underfloor heating: the MVHR delivers filtered air at close to room temperature and the slab does the heating. Summer bypass lets cool night air in without recovering heat you no longer want.
Our MVHR installation service page walks through the process, and eco-friendly heating and cooling explains how ventilation fits into a low-energy home.
Written from on-site experience by the AHHAC Technical Team.
AHHAC's in-house design and service team — licensed plumbers and hydronic engineers (Lic 262528C) who have designed and installed 2,400+ hydronic heating, cooling and hot water systems across Australia since 1998.
We only specify equipment after a heat-loss and system-compatibility check, then supply, install and commission it with our own licensed plumbers to AS/NZS 3500 (plumbing) and AS/NZS 5601 (gas), register the manufacturer warranty and service it for the life of the system.
Essential for tight-built modern homes (Passivhaus, certified high-performance), homes with high indoor pollutant levels, asthma/allergy sufferers, and any home in bushfire-prone areas. Older draughty homes can usually skip it.
Zehnder ComfoAir (premium, quietest), Stiebel Eltron LWZ (German), Mitsubishi Lossnay (good value), Brink Renovent (Dutch). We size each unit to your home's air volume — undersized cycles too fast, oversized wastes energy.
Whisper-quiet — under 25dB at the diffuser on normal mode. The unit itself is mounted in a service area (laundry, garage, plant room) where you don't notice it. Boost mode (during cooking) is louder but still acceptable.
"AHHAC delivered our 22-zone underfloor system on time, on budget and to spec. The crew were tidy, the documentation was thorough, and the commissioning was textbook."
"We've worked with AHHAC for 17 years. They've installed and serviced our hot water plant across three commercial buildings — and they pick up the phone on weekends."
"Three mobs quoted us; AHHAC's design was the only one based on a proper heat-loss calculation. The system runs beautifully — the others would've been oversized and expensive."