How often should I get my AC’s cleaned?


An air conditioner’s filters, coils, and fins require regular maintenance for the unit to function effectively and efficiently throughout its years of service. Neglecting necessary maintenance ensures a steady decline in air conditioning performance while energy use steadily increases.

Air conditioner units that are located in or near the kitchen (as well as air conditioners that are located in the same room as an open kitchen) often need to be deep cleaned more frequently than the other units in your home. This is due to the vapors and oils that are emitted during various cooking processes which will unavoidably be drawn into the air conditioner unit – especially if it is operating when you are cooking. One only needs to note the significant build up of oils on your range hood and other kitchen surfaces to understand how this occurs.

Other factors which will have a significant impact on how rapidly dust, mold, mildew, algae, and grime will accumulate within air-conditioning systems are;

  • Humidity levels
  • Location of the air conditioning system relative to other sources of moisture
    (i.e.: located in close proximity to a bathroom with poor ventilation)
  • The presence of carpets and/or rugs
  • The proper original installation of the air conditioning system
    (If not installed at the correct gradient, the drain pan will be prone to developing mold and algae)
  • How frequently the surrounding environment is cleaned and cleared of dust and other biomatter such as pet fur
  • Environmental air quality
  • The diffusing of essential oils and/or the burning of incense and/or the burning of scented candles
    (Anything that is added to your indoor air, be it vapors from cooking, vapors from diffusing essential oils, carbon from burning candles, etc. will ultimately end up accumulating on the external and internal components of your air conditioning systems)

Taking steps to ensure that indoor air quality is good, and humidity levels are low, will decrease the frequency that air conditioning systems need be deep cleaned and sanitized.


Are you experiencing any of the following? Then book an appointment with us today!

Higher than expected electricity consumption?
An untreated air conditioning unit can increase your energy consumption by up to 20%. How? Over time, contaminants will build up within the coil and the fan barrel, restricting the amount of airflow that can pass through your unit’s coil fins while also weighing down the fan barrel. Even dusty and clogged filters can impact your AC’s energy consumption from between 5% to 15%. All of these issues cause the unit to draw more power, over-working your air-conditioner, and results in greater electricity consumption.

Longer time to reach desired room temperatures?
A split-type air-conditioner’s fan barrel is a long cylinder with small plastic fins, each spaced apart approximately by 1cm, which surround the barrel. Over time, contaminants will build up between the fins and restrict the airflow. Likewise, contaminant buildup in the coil fins also restrict airflow. This causes your air-con to take longer than usual to cool/heat your room. After our clean, your air conditioning units will reach the desired temperature faster and reduce excess electricity usage.

Cold & Flu Symptoms?
Every time your air conditioner runs, the build-up of harmful contaminants inside your air conditioner unit circulates them into the air that you breathe, and throughout your home. Air conditioning cleaning is highly recommended for those who suffer from asthma, sinus, and other respiratory symptoms. Having your air conditioning systems professionally cleaned will eliminate all mold and other unsanitary elements that are thriving within your air conditioning units, which in turn reduces cold & flu-like symptoms.

Understanding your air conditioning system operation

Air is drawn from the room in your office or home through a return grill and passes through an air filter and into the ‘air handler’ (head unit). Contrary to what many consumers believe, neither split-type air conditioners or window-type air conditioners draw air from outside – almost all types of air conditioners recirculate the air inside your home or office.

Inside of the air handler is the circulating fan, and a heat exchange coil commonly called the evaporator. The evaporator is cold and thus removes heat from air that blows across it. In addition to removing heat, water also leaves deposits on the evaporator surfaces. The cooled air returns to the room via outlet grills. The moisture falls into a drain pan under the evaporator and drains through a pipe out of the system.

Sources of microbial contamination in air conditioning

The air drawn into a system in your home or office contains dust, much of which consists of biological spores and other organic particles. Even the best filters capture only part of this material. Much of the rest falls out of the air stream onto the heat transfer surfaces within your air conditioning system. It combines with the condensation and the spores germinate and grow rapidly.

Indoor air quality and microbial contamination in air conditioning systems

Air conditioning systems can become breeding grounds for mold, mildew, and other sources of biological contaminants and can then distribute these contaminants throughout your home or office.

Of greatest concern is biological growth and bio-aerosol generation, most of which are potential allergens. Airborne allergens in the home or office constitute one of the most difficult types of allergens to avoid. Unfortunately, heating and cooling air conditioning systems are excellent harbors for molds, and an air conditioning system makes for an efficient distribution system!

Cleaning your air conditioner filters regularly is a good habit, but it’s not enough

You should definitely clean the dust from the filters of your air conditioning systems at least once per month during periods of frequent usage. You may even regularly wash it in antibacterial solutions. But contaminants such as mold and bacteria will swiftly return, and it’s inevitable that they will contaminate the internal components of your air conditioning systems that you cannot see. The moist environment created inside your air conditioner through its normal operation is the ideal environment for mold and bacteria to grow and flourish in as little as 2 or 3 months – particularly in Hong Kong’s humid environment.

The real problems lay in the areas you can’t reach; the coil, fan barrel, drain pan, and drain line are all moist environments which mold, fungus and bacteria thrive in. The best way to ensure that your home or office is protected is to have the mold, fungus and bacteria removed from your air conditioner, using environmentally friendly cleaning products that also reduce the rate of recontamination. An air conditioner contaminated with unacceptable levels of mold & bacteria can suppress your immune system, cause cold & flu like symptoms, skin irritations, hay fever & trigger asthma attacks. If you want to provide your family with comfort-controlled air that is also healthy then make sure to have your air conditioning systems professionally deep cleaned.

Common symptoms of contaminated air conditioning units

While the symptoms can vary greatly the following complaints have been associated with contaminated air conditioning:

  • Asthma attacks
  • allergies
  • hayfever
  • fatigue
  • sore throat
  • sore, dry eyes
  • respiratory problems
  • headaches
  • tightness of chest
  • frequent colds
  • flu or flu-like symptoms

Other benefits of regular air conditioning cleaning

If you clean and flush your system regularly it will operate more efficiently, use less power and have a longer life span.

Most natural corrosion in air conditioning systems is caused by sulphuric acid secreted by common bacteria that chemically combines sulphur from the air with hydrogen and oxygen from water. These chemicals will have an adverse effect on the coils and fasteners.

Unfortunately, we also note that many unscrupulous air conditioning cleaning companies are utilizing corrosive cleaning products to ‘clean’ the coils, fan, fan barrel, drain pan, and other difficult to reach components of air conditioner systems. They engage in this bad practice out of pure laziness (it cuts cleaning time by more than half) and disregard for the long life of your air conditioning systems. We often see the effects of these bad practices immediately upon inspection of the internal components of your air conditioners; plastic components become brittle, discolored, and are visibly corroded. Metal components are also discolored and corroded. If you have ever had your air conditioners cleaned and you are told to leave your air conditioners running for at least 30 minutes after they have finished ‘cleaning’, then this is likely because they have used corrosive chemicals and they wish for the natural condensation on the coils from normal operation to rinse the corrosive residues away.

Frequency of air conditioner cleaning

Depending on the level of use and environment it is recommended that a split system air conditioning unit is cleaned at least once every 12 months however ideally every 6 months with high usage – which is most often the case in Hong Kong. As a general rule of thumb, we recommend a deep clean in the midst of the summer anytime between mid-June to mid-July so that your AC’s are operating optimally for the peak summer heat, and again anywhere from mid-December to mid-January when you’re no longer operating your AC’s for cooling. For further information as to why it’s exceptionally important to have your AC’s deep cleaned at the end of the summer season when they’re no longer in use – seehere.

Health Research

Millions of people have allergies, and mold is a common irritant. Mold is also a known trigger of asthma. Symptoms of exposure to mold can be as simple as a stuffy nose or watery eyes. In some cases, they can be much more serious. Certain types of mold give off toxins that can be the source of serious health issues.

Not everyone has the same sensitivity to mold so it is possible for one person to experience discomfort while others living in the home too have no symptoms whatsoever. Individuals at the greatest risk include:

  • Allergy and asthma sufferers.
  • People with respiratory disease.
  • People with compromised immune systems.

While mold exists everywhere, it sometimes takes on a dangerous form. The scientific name for the greenish-black mold that turns up on the carpet, wallpaper, ceiling tiles, and of course within air conditioners – is Stachybotrys Chartarum. It produces a mycotoxin that causes mycotoxicosis and strong associations have been made between mold and various adverse effects on human health. Many are known to cause allergies such as hay fever; some are known to be important triggers of asthma.

Tests conducted on building occupants suffering allergic symptoms reported responses to fungi found in air conditioning ducts. A 1994 study found that repeated exposure to spores or other parts of fungi commonly found in indoor air could result in allergies such as asthma and rhinitis; extrinsic allergic alveolitis (a group of lung diseases) or hypersensitivity pneumonitis, which has flu-like symptoms; ‘sick building syndrome’ including symptoms such as headache, fatigue and mucosal complaints; or organic dust toxic syndrome recognized by tightness of the chest, bronchitis and asthma. Those with impaired immune systems are most at risk

The results of tests conducted in homes, offices, schools, hospitals and other air-conditioned buildings indicate fungi are an indoor pollutant of significant concern.

If your air conditioner is contaminated, you are at risk. AirCare Solutions trained personnel will eliminate the source of these issues and neutralize the risk to you, your family and your staff.

Hong Kong residents spend some 90% of their time indoors. Consequently, indoor air quality and the health problems created by contaminated air are issues of incredibly significant community health concern. It is now well documented that poor indoor air quality leads directly to several concerning health effects on the occupants of affected buildings. These range from minor skin and eye irritations to asthma, allergies, respiratory complaints and suppression of the immune system. Legionnaires Disease is just one potentially deadly example.

A World Health Organization report in 1995 estimated that up to one-third of buildings in industrialized countries are aptly named ‘sick buildings’. The issue of air quality is one with very real health and economic implications. It is with good reason that this topic is now amongst the most hotly debated topics in environmental medical literature.

While we all enjoy the comforts afforded to us by modern air conditioning systems, it is important at the same time that we recognize them as a source of potentially harmful micro-organisms and take steps to ensure that they are properly operated and maintained. By simply ensuring that the air conditioning systems in modern buildings remain free of biological contamination, we can go a long way towards improving the health and quality of our indoor environments.