Life of an AC System

Most of us always keep asking this question, as to what is the life of an AC system?

Some say 15 years, some say depends on the brand / make, some say depend on the ambient atmospheric conditions like salinity (saltiness) in the air some say it depends on the usage pattern and maintenance, etc. So the answer is a mix of all the above factors and the formula gets really complex to state in the scope of this article. Actually the life of an AC system is mostly governed by the following factors in the list of priority as given below:

Usage Pattern: This essentially depends on the no. of hours the AC system is operated and the temperature generally set in the room, as it decides the running of the compressor, which is the “Heart of any AC system”.

Preventive Maintenance: This essentially depends on the level of preventive maintenance wherein one pays more attention at ensuring that coils are kept clean, corrosion is kept under control, constant check on gas (refrigerant) in the system and constant check on all rotating & statutory parts. The filters of an AC are required to be checked weekly and they are to be cleaned with running water. This ensures that the air you breathe in the room is clean, as filter are the duct collectors, and if they get chocked with dust, it will obviously reduce the airflow and thereby the motor will get loaded and will have to work at higher speed which will result in higher power consumption.

Proximity to sea: Areas more in proximity of sea side generally have faster corrosion, as salinity in the air corrodes the metal body and the fins (aluminum) exposing the copper refrigerant tubes and joints for further corrosion. This is why we recommend a weather guard be installed on the outer side of the Ac Unit, which keeps the exposure to saline air “minimal” & to that extent enhances the life and reduce the breakdowns.

Brand / Make: Yes, there are a few brands which have special coatings done on the fins. These special acryl pre-coated fin (known as “PE fin”) offer greater resistance against salt damage and atmospheric pollution. Such anticorrosion treatment does enhance the life of the AC System.

High Dusty & Windy Areas: Dust is yet another for of harmful agent to the life of an AC system. Areas with high dust generally end up chocking the coils, whereby the heat transfer through the coils will become extremely difficult. Even wind velocity if it hits the AC system in the opposite direction to the motor/blade movement, it can damage the system and reduce its life.

Electric Poser Supply: This is the food of an AC System, if the food content is suddenly reduced, it will cause starvation and thereby failure of the system. Generally in rural areas and hill stations where power supply is constantly fluctuating, whereby the voltage keeps increasing or reducing suddenly causes a lot of damage to the internal electric winding in the compressor and the electrical parts in an AC system.

Infact in urban areas also, whenever the electric supply fails and comes back immediately within few minutes, this too can cause damage to the AC system. Hence it is always advisable, that no sooner the supply goes off, we must manually switch the AC system “off” and ideal would be to do it with the knob, such that whenever it is restarted again, the correct steps are followed: - which is to first put it on the “fan” mode, and then after 3 minutes on the “cool” mode, this will never load the compressor.

This is very similar to the car or scooter we use, whenever we start the engine from “cold” condition, we first run the engine “idle” (calling “Idling”) for few minutes and then put it in the 1st, 2nd, 3rd & 4th gear. We cannot take a “cold start” & put it in 2nd gear, the car will take a “jerk” & engine “may stop”. This is exactly how the AC system has to be handled as well.

Even when the car has to be halted, we reduce the speed and go on lowering the gear from 3rd to 2nd & 2nd to neutral or 1st depending on the nature of half & throttle a bit, before switching the engine off.

This is exactly how the AC system also must get switched off. By first reducing the speed from high to medium & medium to low & then taking to the fan mode, such that the gas is allowed to come back to the compressor/receiver and then after 2-3 minutes the AC system can be put off completely.

In some larger AC’s there are built in microprocessors & PCB’s to handle the above functions, but it will still be recommended that care must be taken on the steps to enhance the life of an AC system.

Hence the life of an AC system, whether small or big depends on some of the common factors stated above, there are a few uncommon factors also in larger AC system which also govern the life to a large extent like:-

Quality of Water used in Cooling Tower: to extract the heat – herein if the water quality is of “hard water” & “dirty” it can reduce the life of the system, though as a preventive measure, one will have to keep “descaling” the cooling towers regularly, and even opt for a filtration & a softening plant as well depending on the quality of the water. These reduce breakdown & enhance the life of the system.

Finally to answer the question as to what should be termed as “life of the AC system” one has to take live examples from the past.

We have had AC systems working perfectly for even 25 years with good preventive maintenance and reasonable medium of usage pattern in large corporate houses and on the other hand, we have had AC, system finishing its life in just 3 years, namely in installations opposite the sea side or the recent trend adopted by manufactures of making economically priced AC’s wherein the “gauge of the material used is thin” as manufacturers want consumers to buy AC’s again & again, within every 5 years, as even the technology keeps changing so fast.

Infact in marshy areas, particularly where construction

To answer the question as to
what should be termed as
“life of the AC system” one
has to take live examples
from the past.

has been done, the AC system tends to get corroded faster and scientists say that there is some insect, which “eats copper”, this obviously have never been thought of before. These insects tend to cause repeated leakage of gas from AC system and very soon, the coils of the AC system need replacements. The only way to counter such breakdowns is to keep the AC running for at least 10 minutes in a day this will ensure & maintain a constant check on the gas in the system; as many times AC system is left unused for slightly longer time particularly during Winter, which tends to cause gas leakages and corrosion. Again we can relate this to a car, which must always be started on idling at least once in a day for the engine and its oil to remain in working liquid form.

Similarly a constant check on whether the AC system has gas in it, can prevent further damages to compressor as if an AC works without gas, it will have “air” in it and “air” is not compressible, hence if the compressor tries to compress “air”, it will get damaged. Many a times simple observations on the AC can help in determining whether there is sufficient gas in the system, one

The life of an airconditioner
Can be improved with
Pro-active and preventive
Maintenance and constant
Audit of the system will
Prevent breakdowns and
Enhance the performance.

Of the symptoms of gas shortage in the system, will immediately be visible as ice will get formed on the inner surface of the coil, of course it can also happen due to chocking of coil, but generally if it happens without any chocking, it would be due to shortage of gas. Hence the life of an airconditioner can be improved with pro-active and preventive maintenance and constant audit of the system will prevent breakdowns and enhance the performance. We recommend that once in a year, all AC’s must go through a complete check-up like we humans go through a complete medical check for better life.

The heart of the system in an airconditioner is the Compressor, and the brain of the system is the thermostat. The thermostat senses the temperature in the room and gives signal to the compressor to “Cut Off”. So everything revolves around the quality of the thermostat. There are many types of thermostats available in the market and every manufacture uses them depending on their budget / price at which they intend selling. This is why we find the economy & premium models. It is the Quality of thermostat coil & controls, which actually differentiate them as premium or economy models.

It is also important to keep an eye that the water does not collect in tray beyond a point, as this causes the rusting of the body and then the coils. Whereas in a Ductable system, it is extremely important to get the ducts inspected from inside as they eventually end up collecting dust & dirt inside them and because of cold moist times there are some fungal growth too taking place in these ducts. Also check for duct leaks and be sure airflow is not restricted by ducts that are crushed or too small for the system. By inspecting the ducts time to time, one can achieve twofold objectives;

1. The indoor air quality will be healthier for the people who work in these offices/ indoor areas.
2. There will be less load on the Air Handling Unit (AHU) which has to otherwise push the air through the duct, this therefore reduction in the power consumption.

In brief, the factors that increase the life of an AC is adjust the thermostat to the right temperature, clean the filters once a week, get the AC serviced every 6 months, use the right type and capacity of an AC.

The “DO’s & DON’T’S” are; never smoke near an airconditioner as it creates congestion in the machine. Handle small plastic parts as they are fragile and may break. Do not clean filters of your AC when it is plugged.