Air-con: System 3 Or 4 ?

[kst 0]

Hi,

I am not sure I understand your descriptions. It's a little confusing.

Outdoor unit? You mean the compressor?

How much bigger is your master bedroom compared to the other 2 smaller bedrooms? If all 3 bedrooms will need airconditioning at night, then I would not recommend that you get a System 3, and stress one compressor. You should share the load of airconditioning 3 rooms with 2 compressors. And the next questions is which rooms to pair with dining and living.

I guess the living room and dining room airconditioning would be only when you have parties, correct?

Let me have more information on your usuage expectations and then I will comment again.

Hi Chunky Monkey,

Thanks for responding.

I thought Outdoor Unit is the standard term use for the unit you place in the aircon ledge - the aircon

blog guy use this term and so does the aircon salesman. Anyway, yeah, it's the unit that contain

the compressor.

My HDB resale layout (NOTE : master bedroom has raised ceiling since I'm on the highest flr) :

In term of usage, almost every night, master and 1 common room will have aircon turn on for

around 6 hrs. In 1-2 yrs time, all bedrooms will have aircon turn on every night for around 6 hrs.

Living/Dining - rarely on weekdays and more on weekends - maybe 3-5 hrs each weekend day.

every weekend. For the bedrooms, 1 bedroom might have aircon turn on during weekend afternoon

for maybe 3-4 hrs each day.

If I install a System 3 and a System 2, my initial thinking is to use System 3 inverter for the 3 bedrms

and System 2 non-inverter for the living/dining.

Another option is System 4 for everything.

Details of the systems are listed above where I share the quote.

Appreciate your advice.

Edited November 13, 2007 by kst

[Chunky Monkey 2]

Do check with your aircon supplier what he'd recommend and use that as a basis for comparison. What I have posted so far, are based on my personal experiences and the factors that go into my decision making process.

Since in 1 - 2 years' time, you expect all 3 bedroom aircons to be switched on, then a System 3 is not recommended.

If I were in your shoes, I will choose a single unit for my master bedroom. No sharing. Just dedicated for my own use.

And then system 2 for bedroom 1 & bedroom 2, as they are relatively smaller rooms. You will just need one big unit for the living room.

I think by now, you can see that I do not like to overload my compressors. And if you do the load balacing like I have recommended above, only 2 compressors will be running at night, with the occasional one running when you have a party. Will you be OK with that? I know some people think that they are conserving electricity by not working all compressors. But I have a counter opinion. I feel that if a compressor is overworked, the electricity consumption would actually be higher.

I am not saying that this is THE only way of deciding on aircon arrangements. Some families are just happy to have System 2s and 3s and turn them all 24 x 7. The units just don't last so long. In 3 to 4 years, would need to change already. My aircons in my current house has lasted me 7 years and still going strong.

Edited November 13, 2007 by Chunky Monkey

[Cheerful 0]

Yes, I still recommend a System 2. Your current needs may be only 1 bedroom with aircon switched on nightly. What about the future? Perhaps when the kids come along, or when another bedroom is to be occupied by parents or relatives?

Just make sure you do not link both bedrooms to one compressor. It should be one bedroom to say living room, and the other bedroom with dining room.

I always tell my friends to prepare for family expansion or needs expansion. It's best that we depend on natural ventilation but in the eventuality that you need airconditioning, it's better to have more than less.

Thanks Chunky Monkey.

Earlier on,you advised that you will only go for System 4, if at any one time, only 2 aircons will be used. Thinking of the next few years, supposedly when the kid come along (assume 1), I will have to require air-con for the other rm (eg bedrm 2). So 2 aircons will be working every night.

I will on the aircon in the living area only when there r guests or very hot.Taking this into consideration, 2 aircons on regularly and the one in the living area occassionally, do u still think I should get 2 sets of System 2?

Are the trunkings/pipings for 2 sets of system 2 more compared to a System 4? Finally, i do not intend to on the aircon in my MBR every night if possible unless the days r very warm. I am thinking of geting non-inverter type instead of inverter one.What do u think? Thanks. U may wish to pm me yr reply.

[Cheerful 0]

Just to share the quotes I obtained from GC.

Are the quotes reasonable ?

Each quote is based on :

- Grade 22 (thickness=0.71mm) copper pipe

- Class 1 rubber insulation

- 16mm drain pipe

- Inclusive of stainless steel brackets

SETUP 1 (System 3 + System 2)

========================

System 3 (S$3035)

---------

Outdoor : Mitsubishi Electric MXY-3A28VA

Indoor :

1 x MSXY-GA13VA (3.5 kW) - Master Bedroom.

2 x MSXY-GA10VA (2.5 kW) - Bedroom 2 and 3.

System 2 (S$2170)

---------

Outdoor : Mitsubishi Electric MUX-2B24VB

Indoor :

2 x MS-B13VB - Living and Dining.

SETUP 2 (System 4)

===============

System 4 (S$4098)

---------

Outdoor : Mitsubishi Electric MXY-4A28VA

Indoor :

1 x MSXY-GA26VA (7.1 kW) - Living and Dining.

1 x MSXY-GA13VA (3.5 kW) - Master Bedroom.

2 x MSXY-GA10VA (2.5 kW) - Bedroom 2 and 3.

Hi,

I m seriously thinking if getting a Mitsubitshi Non-inverter Aircon, but I was told by a sales person that there is no System 4 Mitsubitshi Non-Inverter in the market now.Is it true? The ones u quoted, r they inverter or non-inverter type?

Also I am thinking of aircon the 3 bedrms _living area.What is yr final decision?Which system setup will u go for?I would like to hear yr opinion. Thanks.

[garfield101 0]

Hi,

I m seriously thinking if getting a Mitsubitshi Non-inverter Aircon, but I was told by a sales person that there is no System 4 Mitsubitshi Non-Inverter in the market now.Is it true? The ones u quoted, r they inverter or non-inverter type?

Also I am thinking of aircon the 3 bedrms _living area.What is yr final decision?Which system setup will u go for?I would like to hear yr opinion. Thanks.

Hi, not true that there is no sys 4 non inverter. I just bought sys 4 mitsubishi non inverter from GC - Causeway point 2 weeks ago. 2800 for everything. Daikin also has sys 4 non inverter which is 2600+. You can go there to verify but I warn you that the sales guy may be the rudest one you will encounter.

[skywolf 0]

Hi guys,

Need some advice here....

My resale unit comes with a mbr, 2 bedrms, 1 study rm and a rather long dining/living area (balcony already levelled). I'm not sure if the ledge can hold 2 compressors. Will chk with town council later.

Current usage - MBR on every night, 2 bedrms not used for now (but prefer to install 1st else next time tedious), Study rm will be used daily (at least on for abt 2 hrs/wkday and more on wkends). Dining/living used more on when ppl comes over - not frequent unless hot weather.

Any recommendation on what kind of AC units? Thanks!