I am wondering when the installers here don't vacuum the air conditioner when it is fitted. I have installed 15 units of air conditioner (Panasonic, York, Daikin, Sharp, Carrier) and never once any of these installations were vacuumed. I believe this is the main reason why air conditioner doesn't last more that a few years before the compressor went faulty. The air and moisture in the piping will cause inefficient of the cooling which leads to higher power consumption and eventually the degradation and breakdown and corrosion of the system.

Of many of the installations, I have purchased the air conditioner from an authorized dealer after calling the brand principal that I want to have the installation vacuumed. Every time I was told "no problem, its OK, sure can..." but end up having some ignorant installer fitting the air conditioner.

The installers will usually say " can one....no problem one....no need to vacuum one....install so many units also no problem...huh? what is vacuum...." So they are trying to say that they are smarter than the engineers/chemists/designers of the manufacturers.

This is a reflection of the lack of knowledge and professionalism of the air conditioner industry in Malaysia.

Has anyone experience an installation that vacuum the pipe first before gas is released / charged?

From my experience, they will vaccum for interter type gas. The R22 some installer do some don't.

My in-law National A/C 2HP still running strong about 10 years now. The installer did not vaccume it.

I don't think vacuuming is necessary. You can purge the air out of the pipe, this is more effective and practical than vacuum.

Yup, my installer purge the refrigerant pipe and the water discharge pipe too

so the installers are smarter than the engineers, no need to follow installation instruction....

Both will give d same effect bro. One you use vacuum to suck the air out, but this method you need extra tools, which is d vacuum pump itself and its time consuming. Another method is using the gas itself to push the air out of the pipe. The second method is d easiest but its not environmental friendly since you release d gas to d atmosphere.
Bro be careful on your words, not all engineers are smart and not all installer are stupid. In some cases engineer do refer to installer to get a better and practical solution.
Im engineer myself, i respected my technician bcoz they have experience and hands on skills. Which engineer cannot learn from d books.

D most common mistake in aircond installation is d piping insulation. Gas and liquid pipe should be insulated seperately. But most of installer they insulate both pipe using d same insulation.

If worry too much, buy the tools and DIY. This is common in Europe, US and Australia because labour cost are expensive.

My friend living in Perth build his own house. Need about two years with some help from church friends.

Its not practical and financially viable to buy all those tools just to install an aircond. All you need to do is observe d work and tell them the right things to do if you have d knowledge. However, If you dont know, just keep silence and let the installer do d job and just accept what ever the result will be.

Ive an uncle, he is an ex army. He built his own home in less then 1 year, in malaysia. Seems like malaysian know how to built house better.

More resources will shorten the time.

Anyway back to the topic, R22 usually they don't vaccum. R410a required to vaccum, my installer came and Diagnos and refill my inverter a/c 3x for the last 12 months and each time he vaccum it. For R22 he did not vaccum. R410a need to vaccum, and can't over fill the gas else not cold or compressor will trip.

vacuum pump not that expensive la. Can use for other things like service car a/c. China mali 500 can get already.

If got time and house got many a/c can consider. Saving is there if service twice a year.

So, what the diff between R410a and R22 that make one need to be vacuum and the other don't?

Don't know not the HVAC expert, the installer told me from his experience. Is similar to Car a/c, the R12 don't required vacuum and can reach its peak performance while the R134a need to be vacuum else is not going to be performnin. That I am sure because I had R12 and R134a in the same car difference engine, even do the car a/c myself for few time and cannot skip the vacuum when dealing with R134a.

Wait, how do you REMOVE air out of the pipes and the water discharge pipes without going through the VACUUMING process?

The current generation should be R32..

p/s: Apologies for necro-ing an old topic but it was quite relevant

Any chance I could receive your input ZeneticX stormer.lyn Benefon

Purging is the short cut method that many aircond installers will use to 'remove additional substance and gases from the system' .... though I am not sure if there's any scenario where its a sufficient / valid method

This post has been edited by ZeneticX: Jun 2 2024, 02:34 AM

Thanks. I went through the aircon's manual which I want to purchase and it did mention about vacuuming:



https://www.midea.com/content/dam/midea-aem...User-Manual.pdf

Not a big issue to do. The competent installer will bring a vacuum pump and use that to evacuate all the air in the system, exactly as the installation document you linked to above. Standing water is removed also, as when the pressure drops, the water changes to water vapour ("boils") and is extracted along with the remaining air.

Conversely, an installer will purge the air in the tubes just by letting a little of the refrigerant gas out, and letting it flow out, supposedly displacing all the air in the pipes. This does not remove any standing water in the pipes though.

It is not for the water discharge pipes, only the refrigerant pipes. Purging has never been a valid way to evacuate the refrigerant lines, because 1. refrigerant is released into the atmosphere 2. it's not a great method and 3. vacuuming serves to check for leaks too.

This post has been edited by stormer.lyn: Jun 2 2024, 08:35 AM