Wednesday, 6 November 2013

Control Wiring

Recently there are many cases of aircon wiring broken or faulty after a few years of installation.
This will lead to aircon not being able to function and owners have to replace their wiring from the blower to the compressor.
In some cases, the wiring is already hidden inside false ceiling or built in cabinets.
Imagine the trouble you need to go through just to replace the faulty wiring.
This is mostly caused by poor quality materials used during the initial installation.
Wiring is as important as the grade of copper piping used.

From the indoor units (Fancoil) to the outdoor unit (Compressor)
Min should be 3c40.
This means there are 3 cord of rubber enclosed wire, each with min 40 strands of copper wire inside.
If they use 4c40, means there is an extra cord for next time backup, in case one cord is faulty in future.
If they use 3c70, which means there are 70 strand of wire inside, this is even better but usually you have to top up a bit of $ for this upgrade as the material cost is higher.

The brand of the wire matters a lot.
Do try to avoid brands made in erm.... u all know. PR*.
Local brands like Keystone & Tai Sin are known to be reliable.

I will advise all owners to confirm the brand of the wiring used by your aircon installer before committing to the purchase.
If budget permits, do consider an upgrade to the 4 cord or 70 for long term usage.

Tuesday, 24 September 2013

NEA Energy Efficency Rating Scheme

As on 1st Sep 2013, some models of air-conditioners are being phased out as they fail to meet the min requirements set by NEA.
They are mostly non inverter single & multi split aircon equipment.
For non inverter, only Daikin multi model Ma56 (connectable up to 4 units) are allowed to be on sale.
Some inverter models failed to meet the min requirement too.
More details @ NEA Website.

Do note on this when considering your aircon purchase.

Sunday, 26 May 2013

R22 gas phase out.

Many users are concerned about the availability of R22 gas.
R22 gas will be phased out in stages, by 2020, it will be reduced by 99.5%.
By 2030, there will be no more production of R22 gas.
Info taken from (

It is still safe to purchase R22 gas equipment now assuming average lifespan of aircon units are between 5-7 years depending on usage.

However, many brands are no longer producing equipment using R22.
Only inverter multi system that uses R22 is Daikin.
Rest are using R410a. (To my knowledge)

So do not worry for now.

Friday, 12 October 2012

Btu Calculation

For most new HDB flats.
4 rooms.
Estimated btu for the bedrooms are 9k btu each.
Living will be 18k btu.

3 rooms
Estimated btu for the bedrooms are 9k btu each.
Living will be 12k/18k.

If you hack the master room and bedroom 2 into one room, i will suggest at least a 12k btu. but 18k will be more comfortable in terms of cooling.

Rough guide for calculation of btu.
Take your square area of the room multiply by a factor of 400-500.
400 for lower requirements/number of people in the area.
500 for higher requirements/number of people in the area.

Say a bedroom square area is 18 square metre.
18 x 450 (middle range) = 8100.
8100 nearest btu is 9k btu.

This formula is taking into account of a ceiling height of 2.5-3 metres.

The same formula can be used for pte apartments.
But for calculation of the living/dining area if the ceiling is of a higher height.
Maybe u can multiply by 600 instead of 500 to factor in the higher ceiling.

A ceiling fan may be useful too for faster distribution of the cold air.


Monday, 20 August 2012

2 trips installation

I have noticed many people asking abt 2 trips installation, especially for home owners whose house are undergoing renovations.

For aircon installation, we can break them up into 2 parts.
1. Running of piping, trunking.
2. Installation of equipment.

For 1 trip installation,
1. It will applies to those who are currently staying in the house 
2. Those who are replacing their current aircon unit.

If your house is undergoing renovation and u install your aircon in one trip.
The aircon installer will usually cover up the fancoil with a plastic sheet first.
There are some issues which i realised.
If the installation is done BEFORE the painting, then the wall behind the fancoil unit will not be painted and 5-7 years down the road , when you need to replace a new system, the wall will be of a different colour and you might need to touch up on the painting.

If the installation is done AFTER the painting, your trunking will not be painted. Trunking is usually glossy white in colour.
Unless your painter is willing to make 2 trips to touch up or you pay extra $ to the painter.

For 2 trips installation,
It is good as after the trunking is run, the painter will paint the trunking and the wall.
When the house renovations is almost done up, the installer will make a 2nd trip to install the equipment.
This requires coordination between the installer and your interior designer.
So sometimes house owner uses the aircon installer which the interior designer recommends as coordination works is easier.
Finding an aircon installer direct may be cheaper, however you may need to coordinate and spend some time going on site to discuss with the installer on the pipe routing.
If dealing through the designer, you can discuss the routing along with your other services, like electrical power point, ceiling etc.

Some companies provide 2 trips installation free, some will charge.
Market price will range from $50 - $150 for 2 trips installation.

Friday, 17 August 2012

Comparison between brands

Confused between what brand to choose during your aircon purchase?

I will do some comparison between different brands for inverter outdoor units.
I suggest getting an inverter unit if you use the aircon units daily for > 6-8 hrs.

I will compare the 3 brands outdoor units which i usually will recommend to my friends for aircon purchase.

Daikin inverter sys 3 R22 gas model :: 3MKD75DVM
Cooling Capacity
This unit has around 27k btu.

Noise Level 

Noise level for all inverter models, i feel that its quiet so no issues if the unit is working normally.
The rated db is 46.

Energy Consumption 
Max rated amp is 13.4 amp.
If unit is running @ part load, amp is around 6.5 amp.
Based on $0.2878 per kwh.
It will cost $0.43 per hr to run the outdoor unit @ part load. 

Mitsubishi Electric inverter sys 3 R410a gas model ::MXY-3A28VA
Cooling Capacity
This unit has around 27k btu.

Noise Level 

The rated db is 48.

Energy Consumption 
Amp stated is 8.5.
If unit is running @ part load, amp is around 6 amp.
Based on $0.2878 per kwh.
It will cost $0.39 per hr to run the outdoor unit @ part load. 

Panasonic inverter sys 3 R410a gas model ::CU-3S27MKZ
Cooling Capacity
This unit has around 27k btu.

Noise Level 
Energy Consumption 
Amp stated is 9.4amp.
If unit is running @ part load, amp is around 6 amp.
Based on $0.2878 per kwh.
It will cost $0.43 per hr to run the outdoor unit @ part load.

All information are taken from catalogue/information given by airconditioning technicians.  
Energy consumption is a rough estimate.

Friday, 16 March 2012

Copper piping

For copper piping, the process of bending it is important.
Improper bending of pipe will increase chances of condensation or poor gas flow (not cold)
Improper bent piping

 Piping should not be bend with bare hands. It should be done using a pipe bender.
Pipe Bender  

Pipe bend with proper tools, nice 90 degrees bend.