How often to clean and sanitise the air conditioner

Updated 2026-09-04 · reviewed by certified technician

In short Manufacturers (Daikin, Mitsubishi Electric, LG, Panasonic) say the same in their manuals: filters washed every two weeks in season, and internal cleaning done periodically by a specialist. ASHRAE requires coil inspection at least once a year and cleaning whenever loaded.

Maintenance follows actual use — Start with the manufacturer’s instructions.
Consider operating hours, environment and observations.
Plan checks and record completed work.
One fixed interval does not suit every unit and home.

Washed filters left to dry on a white towel by the window

What is really happening

Manufacturers (Daikin, Mitsubishi Electric, LG, Panasonic) say the same in their manuals: filters washed every two weeks in season, and internal cleaning done periodically by a specialist. ASHRAE requires coil inspection at least once a year and cleaning whenever loaded.

Our translation for Bucharest: a living-room unit used in summer, one sanitising a year, in spring; a child's or allergic person's bedroom, or a unit that also heats in winter, twice a year; offices, clinics, restaurants, two to four times a year. Construction dust and poplar fluff in the neighbourhood shorten the intervals.

The evidence

Calculator: how often your unit should be cleaned

What to do

Mechanical pressure cleaning of the evaporator, blower and pan inside a collection cover, then sanitising; filters washed every two weeks; room humidity kept between 40 and 60%; the unit dried on fan mode before winter. No sprays over dirt, no bleach in the unit, no refrigerant "top-ups".

Ask your question Report an error

Related threads

Editorial guide · How often

Small office with 4 staff in Pipera – how often do we sanitise the two units?

Explanations and useful checks for this situation: Small office with 4 staff in Pipera – how often do we sanitise the two units?

Answered by technicianRead →

Editorial guide · How often

I had it sanitised in March – do I need another at the end of summer?

Explanations and useful checks for this situation: I had it sanitised in March – do I need another at the end of summer?

Answered by technicianRead →

Editorial guide · How often

Filters every two weeks? Sounds like a lot. Who actually does that?

Explanations and useful checks for this situation: Filters every two weeks? Sounds like a lot. Who actually does that?

Answered by technicianRead →

Editorial guide · How often

Allergic child, unit in his bedroom – does it really need twice a year?

Explanations and useful checks for this situation: Allergic child, unit in his bedroom – does it really need twice a year?

Answered by technicianRead →

Editorial guide · How often

How often should sanitising be done? Does it depend on how much I use it?

Explanations and useful checks for this situation: How often should sanitising be done? Does it depend on how much I use it?

Answered by technicianRead →

Read also

The information on this page is educational and based on cited sources; it does not replace medical advice. We do not do repairs, installation or refrigerant circuit work.