How Long Do Air Conditioners Last – A guide to the lifespan of an AC


Whether you’re considering repairs/maintenance of your current AC or planning to purchase a new unit, you are likely curious to know, “how long do air conditioners last?” A useful analogy is to think of your air conditioning systems in much the same way that you would think of a vehicle – it’s not necessarily the physical age of the AC, but more so the mileage of the AC and how well it has been maintained. An AC consists of mechanical and electronic components just as a vehicle does, which means that from time to time, various components will fail from ordinary wear and tear. There can also be unusual circumstances such as geckos and mice that can cause an AC to fail – click on the mouse (literally) for an interesting article about this.

An air conditioner that is nearing the end of its lifespan will break down more frequently and draw more energy than a newer AC in optimal working condition. With the typical heavy usage of air conditioning systems in Hong Kong, we have observed that air conditioners will last 10-15 years on average. This relatively short lifespan is due to two primary factors; (1) Long, hot and humid summer months with only a few months of cooler weather, and, (2) Surprisingly poor preventative maintenance practices. The lifespan of any AC system greatly depends on how you care for them. Regular maintenance and other techniques can help to extend the life of your AC’s. Landlord’s in Singapore understand the importance of preventative maintenance – air conditioning systems are used all year round as the average temperature is above 25 degrees all year. It is common practice in Singapore for Tenancy Argreements to require that the tenant deep cleans their AC’s four times per year – it is therefore unsurprising that the average lifespan of air conditioning systems there is 15-20 years.

Even the best HVAC systems, on top of their maintenance game as well as undergoing preventative maintenance, will eventually require complete replacement. There are a plethora of articles to be found online that illustrate that a properly maintained air conditioning system can have an extended lifespan of between 15-20 years

This is why it is important to know how long air conditioners last, which factors will have a negative effect on their life expectancy (as well as best practices that can prolong their life expectancy), and how to recognize the signs that it’s time to replace the entire system.

Determinants of an Air Conditioner’s Lifespan

The lifespan of an air conditioner will vary based upon several different factors. Here is a list of the top 3 factors that impact its life expectancy:

1. Size (horsepower) of the AC

Have you bought an air conditioner without taking its size into consideration? This issue is frequently overlooked, but the impact size can have on the life span of your HVAC unit can be massive.

An HVAC unit larger than required will have short cycles, meaning that it will frequently turn on and off. It has short cycles because the cooling/heating demands are met too quickly. For example, if one were to install a 2HP AC in a small bedroom of less than 200 square feet, even if the thermostat is set at 18 degrees, the room will rapidly reach the desired temperature and the external condenser will shutdown temporarily. As the temperature in the room again rises, the external condenser will jump back into action, only for the room to once again rapidly reach the desired temperature, and the cycle repeats over and over in rapid succession. This is why it is referred to as ”short cycling’.

An HVAC unit that is too small than is required will struggle to achieve the desired temperature for the room and thus the condenser unit is overworked which may lead to overheating, and in any case will reduce the lifespan of the AC system. To once again utilize a vehicular analogy – an AC that is too small for the area that it needs to keep cool is like driving a car at 100kmph in 3rd gear for prolonged periods of time.

So either way, an HVAC unit that is not of the right size is going to be overburdened. This will reduce its lifespan in the long run, and with particularly poor installation choices, can as much as halve the lifespan of various components of the AC system.

2. Air Conditioner Maintenance 

If you are serious about extending the life of your AC, you should never neglect proper maintenance. At bare minimum, all types of AC’s (split-type AC’s, window-type AC’s, cassette-type AC’s, Fan-Coil Units, Air Handling Units (AHU’s), etc.) should be deep cleaned at least once per year. It’s worthy of note that in Singapore, it’s common practice for Tenancy Agreements to require the deep cleaning of the AC’s every quarter – so it comes as no surprise that AC systems in Singapore have far longer lifespans than AC systems in Hong Kong. Considering the very significant costs of replacing an AC that has failed prematurely, it is most certainly a worthwhile investment to maintain them in clean working order. AirCare Solutions recommend the deep cleaning of AC’s twice per year – see here for some further insights into a recommended annual cleaning schedule that is suited for the environmental conditions of Hong Kong, as well as typical AC usage in Hong Kong correlating with the seasons.

For all AC’s, no matter what the type, the return air filters should be regularly cleaned to remove dust, mold and other contaminants that will otherwise restrict airflow and thus overburden the AC as well as resulting in degraded performance. See here for some further insights into the negative impacts that dirty filters can have on an AC’s performance.

It’s absolutely essential that the cooling coils of AC’s are maintained in clean condition. As the cooling coil is cold, condensation forms on the coil as the warm air to be cooled passes through it – so it is inevitable that mold will develop on the cooling coil over time, and this will restrict airflow, reduce the performance of the AC, increase energy consumption, and is just generally unhealthy not only for us, but for our pets too.

Most people will have experienced the consequences of not maintaining a split-type AC in clean condition – the woes of suffering from a blocked drainage line and the subsequent dripping as the condensate cannot be evacuated. Whilst this can often also be the result of poorly installed AC’s and/or poorly installed drainage lines, more often than not it is simply the result of an inadequate deep cleaning schedule. See here for the most common cause of dripping split-type AC’s.

External condenser units are the most often neglected, yet vital, components of an air conditioning system – unsurprisingly, when a split-type AC stops blowing cold air altogether, the vast majority of the time it is due to a fault with the external condenser unit. Whether it be a failed component such as a failed capacitor, failed compressor, failed fan motor, or failed PCB, or simply a depletion of refrigerant, most of these issues can be mitigated by having your external condenser units inspected and cleaned at least once every 2 or 3 years. See here for a brief but informative article about the importance of keeping the external condenser coil clean.

3. Air Conditioner Installation

It is commonplace for air conditioning units to be poorly installed. We frequently find that split-type AC’s are installed far too close to the ceiling. As we all know, warm air rises, so the closer a split-type AC is installed to the ceiling, the warmer the air is that it is drawing in – this means that the AC has to work much harder to cool the air in the room to the desired temperature, and it also means that the AC thermostat is not reading the temperature of the air in the room at the level that we’re living in…nobody in the room is hanging around close to the ceiling. Well, except maybe for cats and birds! Ideally (although obviously having an impact on aesthetics) a split-type AC should be installed at least 20cm below the ceiling. However, more often than not, this can be difficult and costly to remedy as the coolant piping and drainage line conduits have also already been installed too high on the wall. So this factor is something to note when investing in major renovations or in situations where relocating the coolant piping and drainage line does not require any major concrete work. It should also be noted that when an AC is installed far too close to the ceiling, in worst case scenarios it can make it impossible to deep clean a large section of the cooling cool as it may not be possible to pressure wash that section of the coil as adequate access has been restricted.

It is commonplace for air conditioning installations to have been the brainchild of an interior designer who has prioritized aesthetics over function and maintenance. Words cannot express how frustrating it can be for our personnel to arrive at a beautifully renovated home to deep clean brand new AC’s for their very first time, only to discover that some genius of an interior designer has rendered cleaning & maintenance entirely impossible by boxing an AC in so that it is impossible to remove the AC casing (which is absolutely necessary for proper deep cleaning to be carried out). Obviously if a split-type AC cannot be properly deep cleaned, then this is going to result in all manner of issues – the lifespan of the AC will be the least of your worries when the drainage line becomes blocked and it cannot be accessed to unblock it!

Split-Type AC’s are frequently installed ‘behind grilles’ (see photos below) for aesthetic reasons. Whilst we completely understand the desire to do so (as AC’s are indeed quite unsightly), there are most certainly several Best Practices that should be strictly adhered to.

Best Practices when recessing a split-type AC behind a grille:

(i) ensure that the AC’s are still able to perform well within their enclosure (consider adequate airflow, unrestricted return-air)
(ii) ensure that there is adequate clearance around the AC so that the front cover can be fully opened in order to perform regular cleaning of the filters, as well as to ensure that the AC casing can be easily removed
(iii) ensure that that the grille itself can be easily removed without needing to unscrew the entire frame to remove the grille
(iv) ensure that the material directly underneath the AC is waterproof and that there’s no cavity where water can pool whenever the drainage line becomes blocked (which happens far more frequently with AC’s that are recessed behind grilles).
(v) Metal grilles or plastic grilles are a far better option than wooden grilles – wooden grilles accumulate mold faster, are prone to rot, and are difficult to clean. Wooden grilles also restrict airflow.

Air conditioners should ideally be situated within a room where they are able to cool the room efficiently as well as keeping the occupants of the room comfortable without the airflow blowing directly where it may not be wanted despite adjusting the louvers as best as once can to divert the airflow. For example, an AC installed directly over a dining table in a narrow dining area is not going to be comfortable, nor is food going to stay warm for very long. Worst case scenario the airflow may even prevent a romantic candlelit dinner :o) AC’s ideally should not be installed where they are exposed to direct sunlight – not only because this may result in false thermostat readings, but also because heavy exposure to UV will eventually discolor the casing of the AC, as well as cause the casing and other plastic components to become brittle prematurely.

The length of the copper piping for any split-type AC system, whether they be split-type AC’s, cassette-type AC’s, fan-coil units, etc. should also be taken into consideration. Unnecessarily long copper piping, no matter how well insulated, adds additional workload to the AC system.

Signs that your Air Conditioner is nearing the end of its life span (or is already over the hill and half way down the other side!) 

Now that you have a far better idea of how many years an AC system can last, and the best practices to maximize its life span, it’s also good to know when it’s time to say goodbye.

Unfortunately if your air conditioning system is not performing the way it once used to (and assuming that the AC system is clean), it may not be a wise investment to make any further repairs, and replacement would be the better choice. Here are several signs that your air conditioning system has completed its life span and likely is due for retirement:

1. Your energy costs have significantly increased

A HVAC unit that is in poor condition cannot remain energy efficient. As an AC ages, it begins losing its SEER value. SEER is the Seasonal Energy Efficiency Ratio; it measures the highest possible efficiency of an HVAC unit.  The decrease in efficiency results in an increase in energy consumption as the air conditioner draws more power. If you notice a sudden increase in your energy consumption, and you can’t pinpoint the exact issue or other reasons have been ruled out, then it can often be due to the age of one or more AC systems. When other reasons have been ruled out, it would be best to arrange a thorough inspection of your AC system(s).

2. Your HVAC system operates on discontinued variants of refrigerant (For example; R12 and R22)

Chlorofluorocarbons (CFC’s) such as R12 and R22 used to be used as refrigerants in AC systems. But owing to environmental concerns and their impact on global warming, these refrigerants have been phased out globally (in some countries they are now illegal) and have been replaced by R410A and R32 which are currently the global standard. Starting from 1st January 2020, Hong Kong completely banned the import of HCFCs, with only a small amount of HCFCs (0.5% of baseline consumption) reserved for repairing and maintaining refrigeration and air conditioning equipment until 1st January, 2030. As a consequence of this, the cost of R22 has dramatically increased as it is in limited supply. So if the refrigerant of your R22 HVAC system is depleted, it’s going to be costly to refill.

Furthermore, as R22 AC systems themselves are well over a decade old, and are no longer in production, spare parts are in short supply and can often be expensive if indeed they are even available.

R410A and R32 HVAC systems are considerably more energy efficient, are more eco-friendly (though R410A does not impact the ozone, it still contributes to the greenhouse effect), so if you still have an R22 HVAC system, now is the time to consider replacing it.

3. Your AC has required a number of repairs within a relatively short time-frame

AC systems are built to be exceptionally resilient to wear and tear. Once again, to utilize a vehicular analogy, if one purchases a quality vehicle, provided that the vehicle is serviced at the recommended intervals with oil changes, oil filter changes, and other common vehicle maintenance is conducted, one can expect to accumulate at least 60,000km without even replacing a headlight.

So if various components of your indoor or outdoor unit have been failing, one should take into consideration the age of the AC system and weigh up the pros and cons of investing in expensive repairs – especially where scaffolding costs are involved for condenser unit faults.

It should also be noted that the AC refrigerant cycle is an entirely ‘100% closed’ system – an AC system should never require refilling of refrigerant. If refrigerant needs to be refilled, then there must be a leak somewhere. Whilst more often than not, the refrigerant has leaked out from the connection point for the copper piping to the condenser unit (which is also the point where refrigerant is added to the system), AC systems can also develop slow (or rapid) leaks where the condenser unit coil has been compromised by corrosion – and the location of the leak can be very challenging to isolate. Repair or replacement of the condenser coil is a costly endeavor, so again, one should consider replacement of the AC if the AC is more than 10 years old and it has required refrigerant refilling more than once.

4. Your AC has begun making loud noises 

AC’s can develop loud noises for any number of reasons, however, with older AC’s, a common cause is the onset of fan-motor failure. If you’re hearing grinding noises, screeching noises, or high-pitched noises, it’s usually related to the fan-motor and/or the bearings. The fan-motor is one of the most costly components of an AC system to be replaced – the part itself is costly, as well as the labor being costly for its replacement. Fan-motor replacement can be easy with well-designed AC models, or it can be complex and cumbersome with poorly designed AC systems. The accessibility of the AC itself can also have an impact on labor costs – as a general rule of thumb, HVAC technicians will typically quote higher fees for AC’s that are installed behind grilles or have been installed in such a way that access is restricted. If a technician has advised you that the fan-motor needs to be replaced, then one should consider the age of the AC system and question whether or not other components are likely to begin failing on the indoor or outdoor unit.

5. Compressor failure

Your AC cannot function without a working compressor. Its job is to compress the refrigerant and pump it through the external condenser coil to remove latent heat. Like a car engine, the compressor is one of the most reliable components of your HVAC system – it has been designed and built (and has had extensive testing) to last for the entire expected lifespan of the AC system. It is therefore highly unlikely to fail before its expected lifespan, and if it has, then is typically due to some other underlying condition or the compressor has been overburdened due to poor installation or an inadequate cleaning regime. In the event of compressor failure, it is generally not recommended to repair as it is very costly, and it is often not possible to identify the cause(s) of the premature failure until after a new compressor has been installed and only then can a technician assess any other faulty components that had contributed to the failure of the compressor. As a general rule of thumb, if an AC is more than 10 years old, it would not be a wise investment to replace the compressor.

The image below is a perfect example of just how resilient external condenser units are designed to be – it’s hard to believe, but the condenser unit with the massive rusted hole in it is still working (and quite well at that!) whilst the other smaller condenser unit has failed.

Should I repair or replace my faulty AC?

Deciding to replace or to repair your HVAC unit can be really tricky

Just like any other appliance, your air conditioner, no matter how old, can be repaired. The main factor that should be taken into account – how much will it cost for repair.

The rule that is generally followed; if the repair costs 50% or more of the original price of your AC, it is better to replace it. And (at the risk of sounding like a broken record with yet another vehicular analogy!) an AC that has had frequent usage for 10 years without any major repairs, is typically the vehicular equivalent of driving a car that has accumulated 100,000km on the odometer, but hasn’t been regularly serviced – components are definitely going to begin failing. An AC that has had frequent usage for 15 years is the vehicular equivalent of driving a car that has accumulated 250,000km on the odometer, and is so rusty that the only thing holding it together anymore is the paint!

If your air conditioner has been with you for more than a decade, it might not need just one-time repair; it is likely to continue to suffer from other component failures – often in rapid succession. The rapid succession of other component failures can be the result of the additional strain placed on other working components when non-critical components fail. There are several AC components that can fail but the AC can continue to operate without any noticeable faults. For example, an AC can continue to run ‘normally’ (often with an imperceptible reduction in cooling capacity) for several months with much less than the optimal amount of refrigerant in the system. This puts a great deal of strain on almost all of the critical components of an AC system. Furthermore, if your compressor – the heart of the HVAC system, has failed, it is often too costly to replace it.

So, instead of letting repair costs keep building up, consider replacing your AC.

The new unit will provide more convenience, less headaches, and will cost less in the long run – you won’t have to call an HVAC professional for frequent repairs, it will be more energy-efficient, and you will have the peace-of-mind (if it’s been installed by a professional and you have followed their advice on size, brand, etc.) that it is highly unlikely to have any issues whatsoever for the next 10 years or so.