Landlord: tenants complain about smell from the air conditioners – what can I ask of them?
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I rent out 3 studios in Militari (Gorjului) and one in Titan. All have 9,000 BTU Midea or Gree units, between 3 and 7 years old. Tenants take turns complaining about mould smell at start-up, and some have 'fixed' it with sprays. As a landlord, what should I do once a year and what is actually the tenant's responsibility?
What is really happening
Evaporator biofilm rebuilds within 1–2 seasons of use no matter how diligently a tenant washes the filters, because filters never touch the evaporator and fan roller – the most contaminated components. Manufacturer manuals clearly separate the two levels: filter cleaning by the user every two weeks and periodic maintenance by a specialist. The sprays tenants 'fix' it with leave residue and remove nothing – and in small rooms with windows barely open, the air recirculated by a dirty unit is practically all the air in the studio.
- Deposits or moisture inside the unit.
- The condensate drainage route.
- Sources within the room, assessed separately.
- Daikin, Mitsubishi Electric, LG and Panasonic recommend cleaning the indoor unit's dust filters every 2 weeks. [Daikin, 2023]
- Daikin recommends periodic maintenance carried out by a specialist, in addition to user filter cleaning. [Daikin Europe, 2020]
- The blower (cross-flow fan) is the most fungus-contaminated component of a split unit, more than the filter or the front of the evaporator. [Indoor Air, 2023]
- EPA warns that the effectiveness of biocides sprayed into air systems has not been demonstrated and their health effects are uncertain. [US EPA, 2024]
What we do on site
- We do all 4 studios on the same day or two consecutive days, scheduled with each tenant.
- At each: collection cover, cleaning solution, pressure wash in place of evaporator, roller and pan, then sanitising solution.
- Outdoor unit on each balcony, washed in place.
- We send you before/after photos on WhatsApp for each address – useful for the flat's file and as an argument with the tenant.
- See current rates on the Prices page.
What you can do yourself
- Tenant: filters washed every two weeks, 'Fan' 20 minutes before shut-off, daily airing.
- You: a short clause in the contract with these duties and your annual sanitising.
- Leave a laminated sheet in the studio with the two rules.
What NOT to do
- Do not let tenants 'sanitise' with store sprays – the residue comes back to you with the next tenant.
- Do not postpone sanitising until the tenant changes – meanwhile the unit makes smell and complaints.
- Do not accept a 'service' without water washing and a cover.
Prevention
A simple calendar: sanitising in April–May at all addresses, filters by the tenant. With that, smell complaints vanish and the units pass 10 years without trouble.
When to call us
For landlords with several addresses we schedule in a batch: 0764 012 943, Monday–Saturday 08:00–20:00.
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Read also
- Bad smell from the air conditioner
- The air we breathe at home
- Symptoms of an uncleaned air conditioner
Sources (9)
- web-manual.dit-daikin.com/ra/en/cleaning_filters/
- www.manualslib.com/manual/3613226/Mitsubishi-Electric-Msz-Ln18vg2w.html?page=7
- www.lg.com/africa/support/product-help/CT20080060-20153301478951
- www.manualslib.com/manual/1236787/Panasonic-Cs-Vu12skq.html?page=13
- www.daikin-ce.com/content/dam/document-library/operation-manuals/ac/split/ftxf-d/FTXF-D_Op
- onlinelibrary.wiley.com/doi/10.1155/2023/8984619
- www.epa.gov/indoor-air-quality-iaq/should-you-have-air-ducts-your-home-cleaned
- anpc.ro/
- www.ashrae.org/file%20library/technical%20resources/standards%20and%20guidelines/standards
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.