Fresh air, without losing the heat.

No — and this is the single most common misconception. HRV/ERV is a ventilation system. It moves fresh air in and stale air out continuously. The "heat recovery" part means the system salvages the heat already in your home's outgoing air rather than throwing it away. You still need separate heating (hydronic, ducted reverse cycle, splits) and cooling (AC) for the temperature side. Where HRV/ERV reduces heating and cooling loads is by not letting all that conditioned air escape unrecovered when the home ventilates.

For most existing homes, no. Ducted reverse cycle recirculates indoor air — it doesn't bring fresh outdoor air in. Older homes ventilate naturally through gaps in the building envelope (around windows, doors, eaves), and that's usually enough. HRV/ERV only becomes worth installing when the home is airtight enough that natural ventilation isn't sufficient — i.e. when sealing the building envelope has been a deliberate design decision.

The technical answer is in air changes per hour at 50 Pascals (ACH50). Australian standard volume-built homes test around 10–15 ACH50 — quite leaky. Modern 7-star NatHERS homes might be 5–8 ACH50. Passivhaus requires under 0.6 ACH50. HRV/ERV starts to genuinely earn its place around 3–5 ACH50; it becomes essential at Passivhaus levels. If you haven't had a blower door test, an honest sense of when the home was built and whether it's been sealed/double-glazed gives a reasonable starting point.

System selection depends on the project's specific requirements — capacity, available space, controls, target efficiency. We work with the major HRV/ERV manufacturers serving the Australian market and recommend based on the design brief, not stock. For Passivhaus or near-Passivhaus builds we typically specify systems with verified heat exchange efficiency ratings appropriate to the home's airtightness target.

The main ongoing requirement is filter changes — usually annually for residential systems, sometimes twice yearly in dustier locations. The heat exchanger core itself requires periodic inspection. Skipping filter maintenance is the single biggest cause of HRV/ERV systems underperforming or causing indoor air quality issues themselves. We design installs so the filters are accessible — and we can do annual servicing.

Modern residential HRV/ERV systems run very quietly — typically inaudible in normal occupied rooms when properly designed. Noise sensitivity matters most at the diffuser locations (where air enters bedrooms) and at the unit itself (typically located in a service cupboard or roof void). Quality install includes acoustic damping at both points.

Possibly — but it's significantly more involved than retrofitting most other HVAC systems. The constraints: you need ductwork to every room being supplied or extracted, the unit needs a sensible location with outdoor air access, and the home needs to be airtight enough for the system to actually deliver value. For most existing homes the honest answer is that the cost-to-benefit doesn't stack up unless the home is already being significantly renovated.

Passivhaus certification requires both an airtightness target (under 0.6 ACH50) and continuous mechanical ventilation with heat recovery. HRV/ERV is therefore not optional in a certified Passivhaus build — it's part of the standard. We work with Passivhaus consultants and architects on certified and near-Passivhaus residential projects. Vitali holds the Passive House Tradesperson credential.