We often see retailers giving out free material upgrades for new residential air-conditioning purchases. Do they actually improve the AC system performance, or simply a trick to sway buying sentiments?

Offered:
Pipe insulation upgrades from 3/8” (9.525mm) to 1/2” (12.7mm) thickness.
Some offers included upgrading insulation to brand 'Armaflex', and/or improving from Class ‘1’ to Class ‘0’.
Equipment manufacturers recommendation:
Polyethelene foam, heat transfer rate of 0.041 to 0.052W/mK over range of operating temperatures, at least 6mm – 10mm thickness.
Airconreviewed recommendation:
Polyethelene foam, heat transfer rate of no higher than 0.041W/mK over range of operating temperatures, at least 10mm thickness.
Verdict:
Good to upgrade. On conditions that insulation specification requirements are met, we believed most brands on offer are suitable for installation.
Reference to Armaflex catalogues, thermal conductivites for both classes are the same. However, Class 0 is tested to fire classification BS476 Pt 6 & 7, whereas Class 1 is only tested to BS476 Pt 7. Also for Armaflex Class ‘0’, they have a built-in MICROBAN® anti-microbial product protection that reduces mold and bacteria growth.
Pipe insulation upgrades from 3/8” (9.525mm) to 1/2” (12.7mm) thickness.
Some offers included upgrading insulation to brand 'Armaflex', and/or improving from Class ‘1’ to Class ‘0’.
Equipment manufacturers recommendation:
Polyethelene foam, heat transfer rate of 0.041 to 0.052W/mK over range of operating temperatures, at least 6mm – 10mm thickness.
Airconreviewed recommendation:
Polyethelene foam, heat transfer rate of no higher than 0.041W/mK over range of operating temperatures, at least 10mm thickness.
Verdict:
Good to upgrade. On conditions that insulation specification requirements are met, we believed most brands on offer are suitable for installation.
Reference to Armaflex catalogues, thermal conductivites for both classes are the same. However, Class 0 is tested to fire classification BS476 Pt 6 & 7, whereas Class 1 is only tested to BS476 Pt 7. Also for Armaflex Class ‘0’, they have a built-in MICROBAN® anti-microbial product protection that reduces mold and bacteria growth.

Offered:
Refrigerant copper pipe upgrades from SWG23 (0.61mm) to SWG22 (0.71mm) thickness.
Equipment manufacturers recommendation:
Refrigerant copper pipe, C1220T-O, 0.8mm thickness.
Airconreviewed recommendation:
Refrigerant copper pipe, C1220T-O, 0.8mm (SWG21) thickness.
Verdict:
Refrigerant copper pipe thickness must be at least 0.8mm thick. R410A operating pressure is approximately 1.6 times as that of refrigerant R22. Anything less is not recommended.
Refrigerant copper pipe upgrades from SWG23 (0.61mm) to SWG22 (0.71mm) thickness.
Equipment manufacturers recommendation:
Refrigerant copper pipe, C1220T-O, 0.8mm thickness.
Airconreviewed recommendation:
Refrigerant copper pipe, C1220T-O, 0.8mm (SWG21) thickness.
Verdict:
Refrigerant copper pipe thickness must be at least 0.8mm thick. R410A operating pressure is approximately 1.6 times as that of refrigerant R22. Anything less is not recommended.

Offered:
Condensate drainage pipe upgrades from 13mm to 16mm dia, with insulation.
Equipment manufacturers recommendation:
At least 13mm nominal diameter polyvinyl chloride pipe, with insulation.
Airconreviewed recommendation:
At least 16mm nominal diameter polyvinyl chloride pipe, with minimum insulation thickness of 1/8” (3.175mm).
Verdict:
Good upgrade. We strongly recommend a bigger drainage pipe, with insulation.
Condensate drainage pipe upgrades from 13mm to 16mm dia, with insulation.
Equipment manufacturers recommendation:
At least 13mm nominal diameter polyvinyl chloride pipe, with insulation.
Airconreviewed recommendation:
At least 16mm nominal diameter polyvinyl chloride pipe, with minimum insulation thickness of 1/8” (3.175mm).
Verdict:
Good upgrade. We strongly recommend a bigger drainage pipe, with insulation.

Offered:
Wire cables upgrade from 3C40 to 4C40 or 4C70.
Equipment manufacturers recommendation:
1. Power cable (between power isolator and condenser)
- H07RN–F 3-core 1.5mm2 / H05RN–F 3-core 1.5mm2 / IEC 57 3-core 1.5mm2 / IEC 66 3-core 1.5mm2
2. Connecting cable (between condenser and fan coil unit)
- H07RN–F 4-core 1.0mm2 / H05RN–F 4-core 1.5mm2 / IEC 57 4-core 1.0mm2 / IEC 66 4-core 1.0mm2
Airconreviewed recommendation (General HDB residential requirements with negligible voltage drop):
1. Power cable (between power isolator and condenser)
- Grade H05RN–F 3-core 1.5mm2 or IEC 57 3-core 1.5mm2 or higher
2. Connecting cable (between condenser and fan coil unit)
- Grade H05RN–F 4-core 1.0mm2 or IEC 57 4-core 1.0mm2 or higher
Verdict:
Cable upgrades information lacking.
Power cables require at least 3-cores for ‘Live’, ‘Neutral’ and ‘Earth’.
Connecting cables require at least 4-cores for ‘Live’, ‘Neutral’, ‘Earth’ and ‘Signal’.
Sizing of cables must comply to SS CP5:1998.
Wire cables upgrade from 3C40 to 4C40 or 4C70.
Equipment manufacturers recommendation:
1. Power cable (between power isolator and condenser)
- H07RN–F 3-core 1.5mm2 / H05RN–F 3-core 1.5mm2 / IEC 57 3-core 1.5mm2 / IEC 66 3-core 1.5mm2
2. Connecting cable (between condenser and fan coil unit)
- H07RN–F 4-core 1.0mm2 / H05RN–F 4-core 1.5mm2 / IEC 57 4-core 1.0mm2 / IEC 66 4-core 1.0mm2
Airconreviewed recommendation (General HDB residential requirements with negligible voltage drop):
1. Power cable (between power isolator and condenser)
- Grade H05RN–F 3-core 1.5mm2 or IEC 57 3-core 1.5mm2 or higher
2. Connecting cable (between condenser and fan coil unit)
- Grade H05RN–F 4-core 1.0mm2 or IEC 57 4-core 1.0mm2 or higher
Verdict:
Cable upgrades information lacking.
Power cables require at least 3-cores for ‘Live’, ‘Neutral’ and ‘Earth’.
Connecting cables require at least 4-cores for ‘Live’, ‘Neutral’, ‘Earth’ and ‘Signal’.
Sizing of cables must comply to SS CP5:1998.
Positive upgrades are definitely recommended. But do expect to see larger sized trunkings running across your rooms with the upgrades. And, never discount good workmanships. It is still key to an optimal performing and long lasting system.
*This article is written based on a few assumptions.
1. HDB precinct, 2. R410A air-conditioning units with FCUs not exceeding 18,000btu, 3. Non-VRF systems.
*Seek further advice from a certified air-conditioning installer on the specifications of the system, and their recommended materials, prior to installation.
airconreviewed. 08 November 2019
*This article is written based on a few assumptions.
1. HDB precinct, 2. R410A air-conditioning units with FCUs not exceeding 18,000btu, 3. Non-VRF systems.
*Seek further advice from a certified air-conditioning installer on the specifications of the system, and their recommended materials, prior to installation.
airconreviewed. 08 November 2019