A seasonal ventilation maintenance checklist
Why maintenance changes the air
A recovery ventilator is sized to move a specific amount of air. As filters load with dust and the core collects debris, resistance rises and actual airflow drops. The system keeps running, but it quietly ventilates less than intended — which can show up as stuffier air or harder-to-control humidity long before anything looks broken.
Filters
Filters protect both the core and the air you breathe. They are also the item most likely to be forgotten.
- Check them on a regular schedule rather than waiting for a problem; how fast they load depends on the household, pets and the season.
- Clean or replace according to the manufacturer's instructions for your specific unit.
- Reusable filters should be fully dry before they go back in.
The recovery core
The core is where heat exchange happens, so keeping it clean preserves both efficiency and airflow. Many residential cores can be removed and cleaned following the maker's directions. Handle plate cores gently — the thin channels are easy to deform.
Condensate drain
An HRV produces condensate as it cools moist exhaust air. That water leaves through a drain line and trap. If the line clogs or the trap dries out, water can back up or odours can enter. Confirm the drain is clear and the trap holds water as part of seasonal checks.
Grilles and ducts
Supply and exhaust grilles in rooms collect dust around their edges, and exterior hoods can gather leaves, insects or, in winter, frost. Keep both ends clear so the system is not fighting an avoidable restriction. Duct interiors are generally left to professionals.
Signs something is wrong
Stuffy air despite the system running, rising window condensation, unusual noise, or a unit that short-cycles can all point to restricted airflow, an iced core, or controls that need attention. Persistent or unclear problems are worth a licensed contractor's visit rather than continued guesswork.