In hot and humid Singapore, having an air-conditioner is absolutely essential. When you rent a condo/HDB unit in Singapore, you are required (by contract) to hire an aircon servicing company for quarterly maintenance. But when you own your home, it’s easy to forget to maintain your aircon units. This might be why aircon units in rentals tend to last a bit longer than aircon units in owner-occupied homes.

The aircon units in the last 2 places I rented were both 15+ years old. Yet according to, most HDB aircon units only last between 6-8 years. This troubled me, so I decided to take an (offline, paid) aircon class to find out 1) how to service my own units, and 2) how to make my units last longer.

Although I paid $300 for the course, I felt that if I could achieve both goals, it would be well worth it in the long run.

Of course, I tried to find free online materials first. But I wasn’t able to find any that were high quality. (It turned out the internet did have quite a few resources, but I just didn’t know what terms to search for.) I also tried looking for a good library book on how to service/maintain multi-split type air conditioners, but wasn’t able to find any.

About halfway through “Introduction to Air-conditioning and Refrigeration Systems” (the offline course I paid for), I revised my search terms and uncovered a myriad of free online material. And I’m going to save you time and trouble, and just share them with you here.

I’m also going to share what I found useful from the paid, offline course I took. That way, you can decide for yourself whether you want to sit through 3 days (24 hours) of classroom lectures.


Good videos to watch to understand how your aircon system works

In many ways, I felt that these videos did a better job than the offline lecture I had paid for. These videos also were more visually appealing than the hand-drawn diagrams the lecturer did on the whiteboard.


After watching the above video, I was then made aware of the entire e-learning collection from Danfoss. There, I found a complete series of free relevant courses (you just need to register to get access) a “Refrigeration Fundamentals” e-module, and an entire curriculum on “Installation & Troubleshooting Training Program for A/C and Commercial Refrigeration Products”.

After binge-watching a series of these short videos, I instantly became the most knowledgeable person in my (offline) class. One guy even said to me, “I’m going to sit by you so I can copy from you.”


Review of Avanta’s “Introduction to Air-conditioning and Refrigeration Systems” course I took

If you’re interested in taking a hands-on class to teach you practical skills to service your own aircon or to go into the aircon servicing trade, this class will not get you there. It is mostly theory, and resembles a college Thermodynamics course. But the textbook is terrible; it’s just printouts of PowerPoint slides. Though I suppose if you wanted a course just for basic understanding and not really for any practical application, this course isn’t bad for the price.

For me, I felt a bit disappointed because it was advertised as a useful, practical, hands-on course. Before signing up for the course, I asked one of their staff whether the course would equip me with in-demand, job-ready skills. Confidently, the manager said, “Yes!”. Some of the course was indeed hands-on, but the vast majority was comprised of lectures on theory.

With that frame of reference in mind, in short:

  • The useful: For roughly 2 hours, we disassembled/reassembled an aircon unit (the condenser unit and the fancoil). This was the only hands-on part of the course.
  • The not-so-useful: For most of the remaining 22 hours, we just sat there to listen to lectures. In the final 2 hours, there was an exam. But because we were essentially given most of the answers in the hour preceding the exam, I felt the exam was useless.

Though, every now and then, amidst the sleep-inducing sound of the lecturer and the humming of the classroom aircon unit, there would be tidbits of useful information. For example, the lecturer said that most aircon units today fail because of the compressor’s PCB (circuit board). This is because of the countless times the compressor has to switch on and off in any given day.

Another thing he said was that he personally cleans his aircon filters weekly. “It only takes 10 minutes, and it’s worth it because it makes your aircon last longer and be more efficient [use less energy],” he said.

Lastly, he said that while most people only think about maintaining the fancoils (the indoor units), the compressor (outdoor unit) can get really dirty because of dirt, dust, leaves, and other debris. “You can really extend the life of your aircon by cleaning the compressor at least yearly”, he said.

That’s when I realised that in all the rentals I had previously lived in, the aircon units with compressors that were the most exposed to the elements did not last as long as those where the compressors were sheltered or protected from the elements. In one place I rented, the aircon failed after 8.5 years, but in another place (where the condenser was sheltered), the unit was still going strong after 15+ years.


In Conclusion

Overall, I don’t regret taking the offline, paid course. There were elements of it that I did find to be very useful. It also tested my endurance (it has been years since I’ve had classes lasting more than 2 hours at a time). And it did give me a basic understanding of air-conditioning and refrigeration systems. Though I think you can get the same effect from watching the (free) videos above.

But in terms of being a practical, hands-on course that will give you skills needed for aircon servicing jobs, this particular course (from Avanta) is probably not the best. Perhaps the courses offered by ITE or Daikin might have been better.

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