Air conditioners are a germ haven - clean it!

Air conditioners are a germ haven en banner

It is that time of year again when Hong Kong temperature soars beyond 30 °C. What bad things happen if your air conditioner isn’t used for one year or longer  – you may find ill smell at your home, and air conditioner thermostat not working. Time to get a new one?


Do not throw it out just yet –  One of the only problems that does affect unused air conditioner is a buildup of dust in the system. We do not clean them regularly because we are too busy (true Hong Kong fashion). In 2018, an HKBU research team discovered skin squames are a source of food for the bacteria found in air-cooling units, which produce odors even in a dust-free air-conditioning system.*


In addition, the dust on the frame and dust filter reduce the air intake of the air conditioner and increase cooling time as well as energy consumption. Cleaning your air conditioner regularly could save around 30%** in electricity costs! Save energy by practicing the following 3 simple habits for a cool summer.


Habit 1:

Air conditioners are a germ haven en 1

Before turning on the air conditioner after a year of inactivity, run water to clear the residue on the dust filter and outer cover. Use 1:99 of diluted bleach diluted household bleach (mixing 10ml of bleach with 1 litre of water) for disinfecting the internal metal parts. Wait 30-60 minutes after spraying, then run it on fan mode only to clear out the system.


Internal metal parts are mostly unaffected by bleach. After turning on the air conditioning, the water droplets will disappear while clearing mold from the water hose outlet


Habit 2:

Air conditioners are a germ haven en 2

The best practice is to wash the dust net once every two weeks – just wash it with the shower head facing downwards. Remember not to brush the dust filter because it could damage the dust filter, lowering the efficiency of dust filtering.


Habit 3:

Air conditioners are a germ haven en 3

The stark difference in temperature caused by operation of the air conditioner causes condensation to form on the air conditioner and walls of the room. Hong Kong’s hot and humid days also provide the perfect home for germs to grow.


When you turn on the air conditioning at night, the germs spread everywhere – making us susceptible to getting sick. So remember to use 1:99 diluted bleach to clean the outer cover as well as places where condensation may have formed.


As a last reminder, if your air conditioner has not been cleaned for over five years, get the tip top services from comprehensive air-conditioning maintenance and repair team before summer arrives.


*【教育要聞】浸大研冷氣機傳惡臭 細菌分解皮屑導致|星島教育網 (
**CLP Liberal Studies (
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