What Does an HRV Do — and How Often Should It Be Serviced?

Modern homes are built tight. Good for energy bills, bad for air: without deliberate ventilation, moisture, CO₂ and indoor pollutants accumulate. The heat recovery ventilator — HRV — is the solution BC building code landed on, which is why nearly every newer home and condo here has one humming away in a closet or ceiling.

How it works

An HRV runs two air streams past each other continuously: stale indoor air heading out, fresh outdoor air coming in. At the centre, a heat-exchange core transfers warmth from the outgoing stream to the incoming one — so in January, the fresh air arriving in your living room has already been pre-warmed by the air it’s replacing, recovering most of the heat you’d otherwise throw outdoors.

An ERV (energy recovery ventilator) does the same job but also transfers moisture between streams, which helps manage humidity. From a maintenance standpoint, they’re siblings.

What neglect looks like

Every part of the airflow path collects dust: filters first, then the core, then fan wheels — where even a thin coating measurably cuts capacity. The exterior intake hood adds its own failures: leaves, lint and the occasional bird’s nest. The unit rarely stops outright. It just moves less and less air, while the home slowly gets stuffier, windows condensate more, and nobody connects the symptoms to the beige box they’ve never opened.

A realistic service schedule

• Every 3–6 months: check and clean (or replace) the filters. Many homeowners can do this themselves — the filters usually slide out from the front panel.
• Annually: a full service — core removed and washed, fans cleaned, condensate pan and drain checked, exterior hoods cleared, and connected ducting cleaned where accessible.
• If it’s never been serviced: start with the full service. The first one typically makes an obvious difference.

Our HRV & ERV service covers the complete list, with airflow checked afterward. In multi-family buildings — where hundreds of identical suite HRVs are often all overdue together — we service them as part of coordinated building programs.