Ahnaiz Network: Air Con | Ceiling Fan | Plasma TV | Refrigerator


This section explains the usual dilemma in choosing the best combination of air conditioners in Singapore.

Should i get a System 4 or a System 3+1?

Which combination is better? A System 4 to cater to living room and 3 bedrooms or two systems of Single Split for living room and System 3 for the bedrooms?

Each of these combination have their advantages and disadvantages.
Let's now look at an example.

Ahnaiz decided to air condition his new flat except for the kitchen and study room. Therefore he will need 4 indoor units, 1 for the living room and 3 for the bedrooms. He calculated that the living room need a 18000btu indoor unit while the bedrooms will be sufficient with 9000btu indoor unit each.
But he is faced with a dilemma: whether to get a System 4 for all the 4 indoor units or two systems of Single Split for living room and System 3 for the bedrooms.

Choice 1: System 4 for 1 living room and 3 bedrooms.
The outdoor unit is placed on the aircon ledge and connected by pipings to all the 4 indoor units.

Image Hosted by ImageShack.us
If Ahnaiz decided to get the Inverter System 4, he will have to pay $3700 for a Mitsubishi Electric MXY4A-28VA / MSXYGA-10VA x 3 + MSXYGA-18VA.

Choice 2: Single Split for living room and System 3 for 3 bedrooms.
Both outdoor units are placed on the aircon ledge. The piping for the Single Split runs through the toilet to the living room while the pipings for the rooms run into the master bedroom then to the remaining 2 rooms.

Image Hosted by ImageShack.us
If Ahnaiz decided to get this combination, he will have to pay $1350 for a Mitsubishi Electric MUA-18VD / MS-A18VD and $1900 for a Mitsubishi Electric MUX20TV / MS-A10VD x 3. That comes to a total of $3250.

Suddenly, it occurs to Ahnaiz that he can replace the Non Inverter System 3 with an Inverter System 3 (Choice 3). But he will have to pay $2700 for a Mitsubishi Electric MXY3A-28VA / MSXY-GA10VA x 3. That will come to a total of $4600 with the Single Split.

Next, Ahnaiz compares the different aspects of the combinations.

Choice 1: $3700
Choice 2: $3250
Choice 3: $4600
Ahnaiz feels that Choice 3 is more than what he is willing to pay for. For that additional $900, he might as well go for a longer honeymoon. Therefore he will consider only Choice 1 and 2.
For just an additional $450, he will be able to get an Inverter. With the Inverter he will be able to save approximately 20-30% of his airconditioning bill.
Ahnaiz assumes that his airconditioner will last at worst 5 years, thus he will only have to save $7.50 a month to break even after the fifth year.
Ahnaiz feels that he can achieve the $7.50 easily as he intends to use 3 bedrooms every night and his probable monthly airconditioning bill will come to $70 a month. If the Inverter is able to save 20% then his savings will be $14.
Therefore Choice 1 seems to be better choice.

Cooling Capacity
If Ahnaiz will to use all 3 rooms at the same time, the cooling capacity for each room will be
Choice 1: 8500btu for each bedroom.
Choice 2: 8500btu for Master bedroom and 6000btu each for the remaining 2 bedrooms.
At this moment of time, Choice 1 seems to perform better.

But Ahnaiz then compares when all the 4 indoor units are used to be use the same time, the cooling capacity for each indoor unit will be
Choice 1:
Living Room: 11000btu
3 Bedrooms: 5000btu
Choice 2:
Living Room: 17800btu
Master Bedroom: 8500btu
2 other Bedrooms: 6000btu each

The Inverter System 4 performs worse. This is because all the 4 indoor units have to share the compressor while the Single Split has its own compressor. Ahnaiz feels that he will have to on the living room indoor unit earlier if he is to have any gatherings.
Ahnaiz then thinks about the chances of he having to operate all the 4 indoor units at the same time. Ahnaiz feels that the chances are only during the festive seasons which is only a few days of a year therefore the Inverter seems to be the better choice.

Choice 1:
1 Outdoor Unit + 4 Indoor Units
Choice 2: 2 Outdoor Units + 4 Indoor Units.
Even though Choice 2 seems to have more components than Choice 1, Inverter components are usually more expensive than Non Inverters.
In this aspects, both choices seems to level out.

Economical Sense
Choice 1: If the compressor breaks down, all the indoor units will be affected and Ahnaiz might have to pay another $3700 to buy a brand new System 4 Inverter.
Choice 2: If the Single Split compressor breaks down, it will only affect the living room indoor unit. The bedrooms are run by the independent System 3 Non Inverter.
Ahnaiz also feels that if after 5years, the System 3 will to spoil, he will only have to pay another $1900 for a brand new system. He reckons that the Single Split will last longer due to lower usage.
At this moment, Choice 2 seems to be a better choice.

As you can see, there is no right or wrong in choosing which combination. Your decision will be determine by which aspect is more important to you. Consider the different aspects and decide which combination best suits you.