Dear All,

The below will be my experience speaking.

R22 (HCFC) gas/ Freon/ refrigerant is what you use in most of the non-inverter models, regardless of brands. The R22 has lower operating pressure, hence it states that you need thinner gas tubes. Top up on this kind of is possible.

R410A (HFC) is the “new” gas where the operating pressure is approimately 1.6 to 1.8 times higher than R22, hence some of the manufacturer is recommending thicker tubes. However, these thicker tubes is not easily available in the market according to market spec, hence the price for these tubes will be high and not lots of installer carries stock. Top up on this kind of refrigerant is also possible, as the boiling point for all the refrigerant mixture is almost the same.

CFC is no longer available in the market. Banned long ago because of the effect to the environment. Production of R22 has been stopped in early this year, and what you get in the market now is recycled R22. Manufacturer assume that the price of R22 will go up as short of supply.

R410A is environmental friendly refrigerant as it does not deplete ozone/ zero ozone depletion potential (zero ODP). However, it still has certain level of Global Warming Potential (GWP). R22 on the other has a very low ODP, and relatively lower GWP compared to R410A

Installer will tell you the below 3 things about inverter pipings:-

1) Nothing will happen if you use thinner tubes, all my customer did not complain
2) Thick tubes I don’t have
3) I buy the tubes for you but it will be bloody expensive

I will say, if you already have new set of tubes installed in the wall, I will say go for it. Some of the manufacturer over-spec-ed their pipe thickness to cover their ass just in case things happened. My experience is the 0.33mm tube thickness (1/4”), 0.56mm tube thickness (1/2”) can with stand 600pascal testing pressure (approximately 450pascal operating pressure). The worst thing that will happen is that the tube will crack and gas will leak. No big deal actually. Since you have already concealed the wall, it is the matter of hacking it now or later. What if the tube did not crack? I am using inverter units with standard piping. Nothing happens…yet. If you are installing new, just get a thick pipe, so that there is no worry.

Tips for new installation of Inverter AC.

1) Make sure that they use the correct tool. For inverter AC, they will have a special gauge for inverter units
2) If you are recharging/ top up your R410A, make sure that the colour of the refrigerant tong is in pink, not other colour. R410A refrigerant only has one packaging. If they tell you can be used, chase them away. Don’t let them charge. Please note also brand new ACs do not need to add gas unless you exceeded their standard pipe length. If your installer says need to add gas, evaluate the piping length. If the piping does not exceed the standard length, and your installer says you need to add, he is conning you.
3) Just in case in any circumstance you are releasing all and re-charging the refrigerant to full, make sure that you know what is the initial amount of refrigerant (before 1st start up), so that you can put a weighing machine below the tong to ensure the real amount of refrigerant goes in. Installer in Malaysia uses only the gauge to measure. This is not wrong, but not really accurate. The pressure goes up by certain level, does not mean that the gas has go in at a certain weight.
4) Make sure that the refrigerant tong is at the right position (standing or reverse standing for certain tong model), to ensure gas form refrigerant is charged SLOWLY into the AC, not liquid. Liquid form of refrigerant will damage compressor at start up.
5) Make sure that the flaring of piping is done properly, no crack, no uneven, etc and please read the manual
6) Make sure your installer vacuum the system (standard procedure) at least for 20 minutes (not Malaysia standard procedure) to take out any residue in the piping before releasing the refrigerant from outdoor to the system. Imagine copper pipe cutting debris goes into your compressor.
7) If you have compressor burnt out and you wish to change AC, I will say dump the existing piping. If there is no choice, get your installer to vacuum the system kao kao kao kao before starting up. This is because burnt out compressor will have lots of “burn dirt” from compressor, sticking on to the pipes, and affecting the performance. Even if the performance is not your concern, the debris which still sticks to the pipe might come out one day and goes to your compressor. Compressor dies fast.
8) After the unit has been start up, the installer will run AC with full blast and lowest set temperature. This is standard procedure, but the important thing is to make sure the refrigerant runs to all indoor unit’s piping, to make sure that there is no clogging. How to do it? Only by touching every portion of fins to feel if it is cold and to see if all the parts has condensation water formed on it. Please differentiate between dripped condensation water and formed condensation water. If everything is OK, you are good to go.