Aircon Installation with Stainless Steel bracket for older HDB

For Home Owners who stayed in older HDB estate, they are required to find certified registered BCA contractor to install the stainless steel bracket. Hoot engages BCA trained installer for air-conditioner works. Please contact us for more information.


Recommended Thickness for Copper Pipe

There are 2 types of offering in the market

  • Gauge 22 or SWG22 which is 0.71mm thick
  • Gauge 23 or SWG23 which is 0.61mm thick

There are different grading and standard given to different pipe diameter of the copper pipes. The household air-conditioning system usually operate at a maximum of 330psi. The standard design of pipe thickness is 1.5 times the maximum pressure however the above specification marginally meets the requirement. But, the aircon system come with a high pressure sensor that cut off the system when there is a high operating pressure.

Thus using both SWG 22(0.71mm) or SWG 23 (0.61mm) is acceptable in market norms. We will definitely go for thicker copper pipe whenever possible.

Insulation Thickness for Copper Pipe

As a engineer, we can calculate the required thickness required for copper pipe insulation.

Assuming standard Air conditioning operation with an ambient temperature of 27 degree Celsius & 77% RH in the room, the requirement for insulation thickness would be minimally 10.5 mm to 12.6 mm for various copper pipe sizes. This translate to 1/2 inch thick insulation which is the current market practice.

So its not free upgrade of material from 3/8 inch to 1/2 inch, it should be standard offer for all AC models.


P.S. If you are in cold country with humidity that is lower, you can use 3/8 inch insulation. Singapore weather is just too hot! So overseas branded insulation doesn't mean its suitable for Singapore climate. =)

Why is my pipe trunking so big?

Due to the market trend of offering upgraded material with 1/2" thick insulation and 16mm Drain pipe with 1/4" insulation. The trunking size for system 4 are usually 2 sets of 4" by 3" trunking. (Refer to picture on the right). So if contractors are offering you material with 3/8" thick insulation and 13mm Drain pipe with 1/4" insulation, you will notice that it is 2 inch shorter (Refer to picture on the left). Anything smaller than this means contractor are squeezing the material into the trunking which will cause condensation issue. Insulation should be lightly packed and not squeeze to ensure best performance of the insulation.

Reuse of existing piping for replacement of aircon system

Aircon suppliers have all come out to say that the pipe can be reuse under certain conditions,

  1. Check condition of pipe by holding pressure for minimally 48 hours
  2. Flush clean the pipe to remove any dirt and contaminants.
  3. Engage professional contractor to perform the above

The recommendations are done mostly by people who have concealed piping in their walls, usually for those who stayed in condominiums. Replacing new piping will be costly as it require hacking and patching of the walls. Though they agree to the above and if you are planning to stay another 10-20 years in your estate. It is best recommend to replace a new set of piping. This can be done by laying it on the wall and covering it with trunking. Most of them would think is hideous but believe me, you will not even notice it after 1 month anyway.

Insulation Installation Guideline

Piping Insulation should always be individual. Only at the connection of the FCU is combine into 1 due to insufficient space at the back of the FCU.