Materials for installation

This post will touch on materials used for aircon installation.

Copper Pipes

1/4 refer to pipe size, 22 SWG refer to the gauge, 15m is the length of the pipe

This is used to transfer the gas (Liquid form) from the outdoor to the indoor unit (blower units) and gas (Gas form) from the indoor to the outdoor.
This is the most important material for the installation as gas travels in it.
Copper pipe comes in different grades.
Lowest is SWG (Standard working guage) 24 or G (guage)24.
G24 refers to the thickness of the copper pipes. 
G23 is thicker then G24, G21 is the thickest among all.

Improper installation/handling of copper pipes may cause the following.
- Condensation of pipes at certain area. 
This will usually happen around the bend part. If the installer uses a proper tool known as the pipe bender to bend, the result will be a nicely bent pipe.
Gas flow will be smooth.
If they use their hand, it may have some acute angle. 
Gas might not flow smoothly and icing might occur, which will lead to condensation. Even with how thick a insulation, it will not stop the condensation. 

I will suggest HDB flat owners to use min G23.
For concealed pipings in condo/pte hse, you may want to upgrade to G22.



Insulation
This is the black rubber foam thing which is used to encase the copper piping.
During operation, the copper pipes are cold and some water droplets will form due to condensation.
The insulation will serve to absorb water droplets.
There are 2 classes of insulation. Class 0 and class 1.
The class refers to the fire rated properties of the insulation. In aircon, we are talking about absorbing water, so do you think its worth to pay for a upgrade from Class 1 to Class 0?

I will suggest to use 3/8 thickness insulation for piping in trunking.
For piping above false ceiling or concealed in wall, you may consider to upgrade to 1/2 thickness insulation.

Wire

3 Cord Wire

Wiring is used as a form of power supply for the aircon system and a form of communication between the indoor and the outdoor units.
For the wiring between the outdoor unit to the power point, usually 3C70 is used. For aircon system up to 36k btu capacity.
3C70 refers to 3 cord, (3 pieces of wire), one for live (brown), one for netural (blue), one for earth (green).
70 refers to the number of copper strand inside a single cord.
Between the indoor to the outdoor units, 3C40 is used.
Reason for a lower grade is because, the indoor unit does not consume a lot of amphere.
1 is for live power supply, another is netural power return. The 3rd is for communication purposes between the indoor and outdoor.


PVC pipe also known as drainage pipe
There are 2 sizes used in the market, 13mm and 16mm. It refers to the internal diameter of the pipe. 
16mm has a bigger diameter and might allow for better flow of drain water and prolong the time taken for the build up of jelly and cause the aircon to leak water.
Some companies also have the good practice of applying insulation 3/8 thickness to the horizontal Pvc pipes.
Vertical pipes do not need insulation as water will fall fast due to gravity.




Trunking

Trunking

This is the plastic casing that encase the copper, pvc pipes and wiring.
It is important that there are of the correct size as getting a size smaller will lead to the copper pipes insulation pressing against one another and increase the chances of condensation.






All information above are my own views. 
Feel free to contact me if you feel there are any wrong/misleading info posted.
Thanks.