Window air conditioners are common in Toronto apartments and older homes. A dirty filter restricts airflow, reduces cooling capacity, increases electricity consumption, and blows dust and mould spores into the room. Clean the filter monthly during peak use and perform a full cleaning at least once per season.
Filter Cleaning (Monthly)
- Unplug the air conditioner
- Remove the front panel — most window AC units have a front panel that pulls straight off or slides out; consult your model's manual if it doesn't come off easily
- Slide out the filter — it is typically a mesh panel sitting directly behind the front grille
- Vacuum both sides of the filter with a brush attachment to remove loose dust
- Wash in warm soapy water using a soft brush — rinse thoroughly
- Allow to dry completely before reinstalling — inserting a damp filter creates mould
Coil Cleaning (Annually)
- With the unit unplugged and filter removed, use a soft brush or vacuum brush attachment to remove debris from the front evaporator coil fins — these are the thin metal fins visible behind the filter slot
- Use a commercial no-rinse coil cleaner spray (available at hardware stores) — spray onto the coils and allow to drip off; the cleaner breaks down organic build-up
- Do not use a pressure washer or high-pressure water on the coils — the fins bend easily and bent fins block airflow
Drain Pan and Mould
- The drain pan at the bottom of the unit collects condensate — it is a common mould growth site
- Access by removing the outer housing (usually 4–6 screws); wipe the pan with a cloth dampened with diluted bleach (1 tablespoon per cup of water) or white vinegar
- Ensure the drain hole is clear — a blocked drain overflows the pan and leaks into the wall
Seasonal Storage
- Before storing for winter: clean the filter, dry the unit completely, and store in a dry location
- Cover the front of the unit with the included cover or a plastic bag while stored
- Before reinstalling in spring: clean the filter and inspect the coils before first use