Smoking indoors – the unit has a yellow layer; how often does it need cleaning?
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My husband smokes in the living room (Bragadiru, house with a yard). The unit (12,000 BTU Gree, 3 years old) has yellowish louvres and at start-up there is an old-ashtray smell, especially in the morning. The filters are brown within two weeks. How often should a unit be cleaned in a smoker's home?
What is really happening
Tobacco smoke is an ultrafine aerosol plus tar that condenses on any cold surface – and the coldest in the room is the evaporator. The yellow-brown layer is a mix of tar, dust and biofilm that holds the smell like a sponge and releases it at every start-up. It is also an insulating layer: it lowers heat transfer and raises consumption, just like ordinary dirt, only faster. Brown filters at two weeks show the loading is 3–4 times a normal one.
- Filters retain some airborne particles.
- The coil transfers heat; during cooling it can collect condensate.
- The blower moves air.
- The pan collects condensate for drainage.
- The 'dirty sock' or musty smell from an air conditioner comes from volatile organic compounds produced by microbial biofilm on the evaporator and blower. [Current Microbiology, 2000]
- Replacing a dirty, clogged filter with a clean one can lower an air conditioner's energy consumption by 5–15% (US DOE). [US Department of Energy – Energy Saver, 2024]
- US DOE: filters should be cleaned or replaced every month or two during the cooling season, more often with constant use, dust or pets. [US Department of Energy – Energy Saver, 2024]
- Washing with alkaline detergent, brushing and high-pressure rinsing reduces fungi inside the unit by more than 99%. [Indoor Air, 2023]
What we do on site
- Inspection and photos: tar shows as a yellow sheen on the fins and roller.
- Sealed double cover, hose to the bucket, foil; alkaline solution with longer contact time (it dissolves tar), adjustable pressure wash in place of evaporator, roller, pan and hose – the water comes out brown-yellow.
- Sanitising; filters washed; louvres cleaned of tar.
- Outdoor unit washed in place.
- Start-up test together – the ashtray smell disappears immediately. See current rates on the Prices page.
What you can do yourself
- Filters weekly, with hot water and dish soap.
- Smoking with the unit off and the window open, or in another room – the only measure that really changes the rhythm.
- 'Fan' for 20 minutes before switching off.
What NOT to do
- Do not spray freshener into the grille – perfume over tar is worse than tar.
- Do not wash the fins with thinner or spirit; the manual forbids solvents.
Prevention
Active smoker in the room: cleaning at the start and middle of the season; filters weekly.
When to call us
0764 012 943, WhatsApp, Monday–Saturday 08:00–20:00; Bragadiru is in our area.
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Sources (5)
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.