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

Editorial guide · Updated 18 September 2026

In short Short answer: the rhythm depends on hours of condensation, not on the calendar – living room daily: once a year; bedroom with children/allergies or used all night: twice a year; office/commercial: 2–4 a year; a guest room switched on 5 times a year: every 2 years, as long as it does not smell and has no sludge in the pan. All three we do in one visit when their turn comes.

This page explains a situation in an editorial format. It is not an open discussion board or a verified customer review. Contact us on WhatsApp about your own appliance.

Situation discussed

I have three units at home (Băneasa, house): one in the living room used every day in summer, one in the bedroom only on heatwave nights, one in the guest room switched on 5 times a year. All Daikin, 4 years old. It makes no sense to sanitise them all equally often, right? What is the rule?

Editorial explanation · Revizie AC

What is really happening

Biofilm grows on the wet evaporator; the more hours the unit cools, the longer the surface stays above 80% humidity and the faster it is colonised. ASHRAE 62.1 requires annual coil inspection and cleaning when dirty; manufacturers require periodic specialist maintenance; the European ventilation cleanliness standard puts intensively used spaces on shorter intervals. In practice: at home, once a year is the baseline; double it with children, allergy sufferers or all-night use; commercial, from twice upwards. The rarely used unit has a different risk – it stays wet after the last run and never dries – so for that one, 30 minutes of 'Fan' at every shutdown matters.

Explanatory diagramMaintenance follows actual use
Maintenance follows actual use
  1. Start with the manufacturer’s instructions.
  2. Consider operating hours, environment and observations.
  3. Plan checks and record completed work.

One fixed interval does not suit every unit and home.

What the studies say
  • ASHRAE 62.1 requires visual inspection of cooling coils for cleanliness and microbial growth at least once a year and cleaning whenever fouling or microbial growth is observed. [ASHRAE, 2016]
  • Daikin recommends periodic maintenance carried out by a specialist, in addition to user filter cleaning. [Daikin Europe, 2020]
  • European standard EN 15780 defines cleanliness classes (low, medium, high) for ventilation systems and requires periodic inspections, at least annually. [CEN / BSI, 2011]
  • Mould does not grow below roughly 80% surface relative humidity, but the cold surfaces inside an air conditioner constantly exceed this threshold. [WHO / NCBI Bookshelf, 2009]

What we do on site

  1. This year: all three, as a 'reset' (4 years, never washed) – sealed double cover, alkaline detergent, adjustable pressure wash of evaporator, roller, pan and hose, sanitising, filters, outdoor units in place.
  2. We leave you a calendar: living room yearly (spring), bedroom yearly (twice if children/allergies appear), guest room every 2 years.
  3. At later visits, units not due are checked free with a torch while we are there – if needed, we tell you.
  4. See current rates on the Prices page.

What you can do yourself

  • Guest room: after each use, 30 minutes on 'Fan' before switching off – it is the unit most at risk of 'moulding while waiting'.
  • Filters on all: every two weeks in summer, regardless of use.

What NOT to do

  • Do not skip the rarely used unit because 'it's like new' – it sits wet and closed.
  • Do not sanitise a normal living room 'three times a year'; there is nothing to remove.

Prevention

Simple rules: many condensation hours = more often; children and allergies = double; commercial = from twice a year.

When to call us

0764 012 943, WhatsApp, Monday–Saturday 08:00–20:00; Băneasa is close.

Clean outdoor unit mounted on a block façade overlooking the neighbourhood
Clean outdoor unit mounted on a block façade overlooking the neighbourhood
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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.