Tucked inside your PVC casing are the insulated copper pipes and PVC condensate water pipe. Under normal condition, there shouldn’t be any condensation.

When there are abnormal condensation, it could be due to:

1) A dislodged PVC condensate water pipe due to poor installation.

I shall try to explain this subject in layman terms, so engineers do pardon me if it is technically not too “correct”.

The copper pipe which is cold (about 10’C) will become wet when comes into contact with air, this is called condensation.
To prevent this from happening, we have to insulate the copper pipe so that it doesn’t come into contact with the outside
air.

What we’ve encountered most of the time is that, the insulators were stuffed into the PVC casing so tight that it flattens.
The insulator which is normally 3/8 inch (~1cm) thick, can be compressed till 1mm “thick”, rather thin. Insulation becomes
bad and may start to condense. The condensation may produce enough water to wet the entire length of the insulator
after some time (probably months). When the insulator is wet, it is useless, it cannot insulate anything. And since it is boxed
up, it doesn’t dry up. Therefore, the moment you encounter this condensation problem, you’ll find that it keeps coming
back.

3) The pipes are exceptionally cold:

1) When you have an abnormal low gas pressure (meaning gas leak); the pipe becomes so cold, it ice up! So check the
gas pressure. But do bear in mind that this icing problem would have caused the insulator to become wet. When it is wet,
it can no longer effectively insulate anything. So you must dry the insulator first, otherwise, condensation is to be
expected even after your recharge the gas.

2) When your fan coil is choked, even the returning pipe will be very cold too; because the “coldness” is not dissipated by the fancoil. Things becomes worst if yours is an inverter aircon. When your aircon is choked, of course it have difficulty cooling the room. So, you lower the temperature on your remote controller, telling the air conditioner to send in more cold gas, which as mentioned above, not “dissipated”. And since the room have difficulty cooling down, the compressor will be working non stop and keep sending in cold gas (inside the copper pipe).

Solution?

What happens if the copper pipe become exceptionally cold? 0’C or lower? You’ll need thicker and better insulator isn’t it?
But normally that’s not an option. Firstly, it is too costly to replace the insulations to thicker ones because it is very time
consuming to do so. Secondly, after replacing the thick insulation, you’ll realise that it can’t be packed into the existing
PVC casing. Thus, we should try to control the coldness of the pipes first, if still it doesn’t work, then go for more drastic
measures like replacement of the insulators. Unfortunately, since it will be so costly, you might as well replace the entire
system, it may cost just as much!

Under good condition, if you turn on the air conditioner for 10 hours and set the temperature at 25’C, the compressor
works about ~3 hours, cutting in and out (for non inverter system). So you have cold pipes for ~3 hours. But if your air
conditioner is dirty and choke up, the compressor will be running non-stop and you’ll have very cold pipes for 10 hours.
No wonder your insulations couldn’t take it!

https://astiquer.com/The solution is a good thorough cleaning, and the casing to be opened to dry the insulation (this is time consuming andcan be expensive to conduct). Thus, normally customers do it themselves, its really not difficult, just very time consuming, I can teach you how to do it.

However,if the insulation is flattened or torn, replacement is the only option.