New Member
Hi ridz,

can help on what system to install for my flat?

basically on air-con at night during sleep time in bedroom 1,2 and 3

my floor plan is here


hi acid,

well i must say that your rooms are relatively big.


MBR requires 12000btu
bedroom 2 and 3 are 9000btu each should suffice.

but for the living and dining.

if you want to air condition like both then its a bit big though like 32000btu.

hence maybe like at least its also 24000btu that you require which is so far the biggest i have ever seen

but if you are intending to like cover only the living area then can opt for like

dining 15000 btu so gotta go for like 18000btu blower

and for the living area then its like 18000 btu so yeah maybe a 24000 btu would be alright.

but if you want for both then i think cool its alright but not like cold kinda temperature.

definitely for your 3 bedrooms you can go for a system 3 with configurations of 9+9+12

and living + dining a 24 would be alright.

but if you want your dining and living to be cold and that when you operate the living plus dining its not at night,

you can actually maybe get a system 4 for the rooms so its a 12MBR+9Rm2+9RM3+12 for dining area to supplement another one in the living areaa which is the 24000btu yeah but i think its not really that necessary.

and also provided you have air con ledge that allows you to have 2 condensing units outside installed and that your running amps for the house is 11amp and your block has been suppliedf with a higher loading. check with hdb for this


New Member
hi ridz,

thanks a lot for your advice
for my case need invertable or not?

heard from someone that some aircon model invertable modes only work when all the aircon is running, else it will runs in normal mode if not all aircon is running.
find the idea or concept funny


hi acid,

not a problem. well in your case for your rooms if its every night for about average 6 hours for each room every night then you are better off with inverter system.

what the person meant is inverter will save you more if you run more than 1 room.

i give you a simple example. say 1 is for max power and 0 is for no power.

for non inverter say you operate one room.

its only at 1 so total power is 1
and when the temperature reach already it wil go back to 0 and that when the temperature increases it will go to 1 back.
so in 8 hours (we count it as 6 hours reach temp then 2 other hours is 0 no need compressor to run)
so total power used for 8 hour period is 6 units.

but if you operate 3 rooms then you 1+1+1 = 3

the same as above 6 hours so 6x 3 so its 18 units.

For inverter system initially yes its running at 1 but when the temperature reaches it does not go to 0 it goes to maybe 0.5 or even as low as 0.25.

now we operate 1 unit so initial power is 1 then as temp is reached it will go to 0.5 or 0.25 say we take it as 0.5 and room usually takes about 2 hours to cool.

so in a 6 hour period.
its 1+1+0.5+0.5+0.5+0.5+0.5+0.5= 5units to operate one room for 8 hours okie?

and for 3 rooms its
5x3 units = 15 units.

so as you can see operating one room inverter or non inveter the margin is only like 1 unit difference

but when you operate 3 rooms then yes with NONinverter you use about 18 units but with inverter you use only about 15 so yeah you see the savings is more when youi operate more rooms. it becomes apparent.

hope this super simplified working can help you understand better oki?


New Member
hi ridz,

thanks a lot for the enlightment.
but if we on aircon say average on alt. nights, do you recommend to buy inverter which is much costly? as my family only on when the nights are warm.


hi acid,

well thats a tough kinda question to ask. its more of how often is that alternate nights where its warm.

i cant help you gauge. im terribly sorry.
but i guess if the operation is going to be for 3 rooms simultaneous more often then maybe inverter is the way to go? just my view yeah?


Acid, allow me to kpo a bit..

First of all, I must say that Ridz is truly an expert in this field with an unbiased opinion.

Secondly, I have to admit that I am a die hard supporter of the use of Inverter aircon.

U have mentioned that u may be using AC for all 3 bedrooms on warm nights. Since a warm night is going to affect all 3 rooms at the same time, I assume that all 3 will be on .. on the same night. That’s a 30K BTU effective load. Not many non inverter models can give u an effective 30K load at the same time. My Mitsubishi catalog says only the biggest MXY-4A38VA can support a cooling load of 2.5/2.5/3.5 at 1 time. Anything smaller, there is no guarantee of coolness. Even the huge Daikin 4MKS80DVM can only give 2.21/2.21/3.08.

Thus.. assuming u require 3 rooms cooled at the time, and there is space for only 1 outdoor unit, inverter models would be the only solution.

And if u are getting that 4A38VA model, might as well get the 4th indoor unit (26K BTU) for the living/dining. 1 outdoor unit serve the whole house. Of course.. the model I am proposing is also probably the most expensive model, using R410A gas. But then again, if the aircon ledge available can take more than 1 outdoor unit, then there may be other cheaper options.

Inverter also has this wonderful feature of a tight temp range, which to light sleepers, is enough a justification to select inverter models.


New Member
hi ridz,

just now on the bus, your calculation came across my mind. think there is no difference in cost saving in term of % when on 3 aircon.

1 aircon on > 1/6 = 16%
3 aircon on > 15/18 = 16%

so its the same % of saving, not the more aircon on, you will increase the % of saving.

Hi yoongf,

can give est pricing of the aircon you quote?

i am aiming to spend <2.5k on aircon


hi acid,

well what you mean by the same % of savings. it does. the calculations that i did for you is the super simplified.

if i do a full detail for you then you will see whaqt i mean okie? i try to find my previous postings.

oh yeah with regards to yoongf quotation

i dun think so. a system 4 commands a price of around 4k

$4,588.50 MXY-4A38VA (QTY:1 ), MSXY-GA10VA (QTY:3 ), MSXY-GA26VA (QTY:1 ).


hi acid

this is one of my previous posting in another thread some of the information such as the rate of electricity is out of date so bear in mind yeah?

alright i am going to do some calculations for yuo. but please do note that this is talking about the perfect or ideal conditions okie? and should not be taken hard and fast

Background; room takes about at least several hours to cool say we take 3 hours to reach desired temperature.

and for inverter once they have reached the desired temperature they will run at minimum and hence later i will show you the differential

for non inverter they will either go maximum or nothing (though care should be exercised that when nothing although my calculations would indicate 0 or nil this is not to be taken as operation in circulation mode (when compressor is off do still consume electricity of several hundred watts too yeah) so just to let you know,

also FYi i am taking the current rate for electricity tariff as $0.2049 per kwh

also for the comparison im going to use the data for inverter system from mitsubishi and non inverter from panasonic would require 2 system 1x system 3+ 1x system 1 for the hall as non inveter cannot support combinations of 9k and 18k at one go yeah.

also i shall take the comparison for over a period of 365 days okie? and then compare the costs in 7 years time to simulate the lifespan of the air con and the cost savings etc. to see if its more worth it to take non inverter or inverter cos of the higher initial outlay costs.

365 days with 52 weeks and hence 104 weekend days okie?

with the infor you have given i shall take the operation of simulataneous of 2 rooms the mbr and room 2 at the same time alright? anbd the living room in the afternoon i shall take it as say 5 hours? every sat and sun?

Inverter - system 4 with mxy-4a28va and 3msxy-ga10 + 1x msxy-ga18
running 3 hours maximum power and 5 hours at min as explained
MBR+rm 2 3h x 1.89 x 0.2049 = 1.161783
5h x 0.6 x 0.2049 = 0.6147
total = $1.77483

365 days = $647.81295
7 years = $4534.69065
this is for two rooms for 8 hours usage daily charge.

for living room
same 3 hours cool at max and 2 hours at minumum

3h x 1.23 x 0.2049 = 0.756081
2h x 0.48 x 0.2049 = 0.196704
total = $0.952785 per day

104 days = $99.08964
7 years = $693.62748

total cost in 365 days = $746.90259
total cost in 7 years = $5228.31813

non inverter we shall take 3 hours at maximum powe to cool and the balance of the 5 hours we are going to take it that the compressor is off for about 1.5 hour (where the temperature is reached) and rest of the 3.5 hour is at maximum.

and for the hall since its 5 hours im going to take 3 hours at maximum and the balance 2 hours fully at maximum.
system 3 CS-9dzwx3 + cu-3c20dkh
system 1 cs -18dkz + cu-c18dkz

2 bedrooms per night
6.5h x 1.850 x 0.2049 = $ 2.4639225

Cost for one night is $ 2.4639225
Cost for one year 365 days is = $899.3317125
cost for 7 years = $6295.3219875

cost for the halls
one day of operation
5x 1.730x 0.2049 = $1.772385

for one day its $1.772385

for one year 104 days = 184.32804
for 7 years = $1290.29628

Total for both rooms and living room for one year is = $1083.6957525

total for 7 years = $7585.6182675

savings for one year from getting inverter versus getting non inverter.

$1083.6957525-$746.90259= $336.793135

Saving for seven years from getting inverter versys getting non inverter

$7585.6182675-$5228.31813= $2357.3001375

BUT This is not the entire savings.

You have to take things into considerations such as i dun have the other other inputs where you have please put it in yourself and then you can see the real savings.

this is what you need
1) the total cost of fixing a system 4 inverter system
2) total cost of fixing up a non inverter system 3 + single split of the 18k unit.

find out the cost and then do the following:

Inverter price - Non inverter systemS prices = savings from initial high inverter system

because the inverter sytem cost more, it saves you more too.. so you need to take the initial extra money that you need to fork out at the beginning stage and then you discount off the savings that you might have had if you had used the inverter system.

when you do that then it will be the actual saving.

cos you spend more then you save more. but when yuo even out? is it really save you more you still spend more cos the inverter cost more to buy in the beginning.

So take the savings you will have from 7 years of operating the inverter unit and then take away from the amount that you initially paid more for the the inverter system.

$2357.3001375 - (extra cost of fixing inverter) = actual savings

do note that if when you buy the non inverter systems the 3+1 system is more expensive than getting the system 4 then the savings is as is.

we come to that once tou have the figures.

this is what i have for the quotes okie

inverter system
5,118 Btu/hr x 3 + 10,236 Btu/hr

non inverter systems

Mitsubishi Electric
MUX-20TV / MS-A10VD x 3
9,000 Btu/hr + 6,000 Btu/hr x 2

and a system 1 for the 18k btu

Mitsubishi Electric
18,000 Btu/hr

hence total price for non inverter systems is
$1800.00 + $1300.00 = $3100.00.

so now we take the difference

inverter -non inverter = extra cost
$3490-$3100 = $390

looking at the initial outlay costs it seemd that you can actually break even you initial outlay cos within the first 2 year.

waht i mean by break even is the point where instead of paying more for the electricity every month by saving more during the installation you are actually saving. get what i mean?

say one year = $336.793135 - 390 = you still haven break even yet
then 2 years = $673.58627- 390= 283.58627 (you have already saved 283.58627 from your second year of operating in terms of electricity bill yuo are paying
then the seven year =$2357.3001375 - $390= 1967.3001375

there you go hope that was useful


New Member
Hi ridz,

many thanks for your help. your opinion really helped cos we did our own calculation and was rather off as compared to the one done by our supplier (Allbest). The lady had suggested 18k one at first for the living hall but we thought it was not enough.

Our own calculation was about 24k+. Guess for the Mit sys 4, we will need to take the 26k blower.

Thanks again


hi IAN,

i hope that i am not too late yeah,

i would rather that you not go to allbest to get your air conditioner. there are a lot of bad revbiew and personally when i tried to get information for them when i was scouting for air con they did not appear as honest i would say,

try honx tax perhaps if you are getting it over at imm.

yes the prices is of course pricier at honx ta x but if you get them to write down the specs like

1) what is the type of insultion
2) what is the brand of insulation
3) what is the size of the drainage pipe (try to get at least 16mm pipe thru-out not 13 cos later serviving easier for you)

and make sure they give the exact same configuarsiont as in model numbers of the air con unit as well as the condenser unit and the quantity.

i am not wrong allbest is cheaper but using 13mm and if you want them tp upgrade they will add.

and finally get both of them to give you final price with all the same specs with GST then you compare the prices its about the same i tell you hence thats when i smell a rat.

i choose the latter not the allbest. i dun like you paint a rosy picture and cheaper prices but the specs is not up to standard. then if you wanna upgrade ytou add on per unit basis.

and honx g tax r really takes care of you. though their warranty is i think only 2 yers but if your installation is really good. really need such warranty meh (i think allbest is 5)

and finally if you are paying by credit card or other modes. they may add other charges please bear that in mind also check with them.

check then you get back to us your opinions.

what is the config that you are trying to get i try to find a quote for you as well yeah>


hi ian,

just to let you know that when you operate the rooms you cannot operate the hall cos then it will not be cold.

i think its either 3 rooms max or 1 hall only if you wanna push it, then 1 hall and 1 room, not the MBR its too big.

and yeah if i am not wrong, yours should be the new 4 room the i think 90 sqm right> and hence check again with hdb if the air con ledge can hold 2 condenser.

if the answer is yes then you would be better off with a system 3 for a 12 9 9 and another system 24.

so yeah.

however if you are really sure that you are not going to have a situation to be needing to cool the hall and the rooms simultaneously,

then you can consider the system 4 with 24 12 9 and 9.

this is a system 4
Mtsubishi Electric

and for the system 3 and a system 1

system 3

this is $3,139.50

system 1 (non inverter do take note yeah?
MU-A24VD (QTY:1 )

price $1,785.00

or system 2 Inverter.

so you choose either the system 3 inverter and system 1 non inverter

or system 3 inverter and system 2 inverter.

but if the hall is not going to be operated most of the time mabe like once a month then you can ipt for non inverter.



which one are you referring to??

if you are talking about the typical split system then yes of course they are.

however you will be limited by a lot of factors such as costs, running current, etc.

But if you are referring to those where its a single unit where half of its body is inside and the other half is outside of the building then yes that would not be sufficient


New Member
any idea where can I get a gd system 3 non-inverter aircon that is preferbly btw $1200-1800? which brand ( fujitsu,toshiba or mit.electric ) is beta ( ez to clean and energy saving)? Was advised by an aircon salesman that if I want a system 4, its cheaper and beta ( will be colder ) to get a system 3 and a single unit for the hall in the long run.true? thanks!


New Member
Mit electric system 3 NI can get for 1880 @ hong t*r
Toshiba system 3 NI can get for around 1550 @ hong t*r (just installed mine)

Normally its better to get a single unit for hall. Cos if you want a system 4, it would definitely not be able to cool your hall and you waste more money &amp; electricity.



i would be more inclined to say what are your actualy needs and also what are the restrictions you might have yeah?

if your apartment only allows one condensing unit then you would have no choice but to stick to a system 4 and worse if your electrical loading is not high then you are even more limited to a inverter system 4 that would be able to step down its ampere while in simultaneous operation.

but do note that if you are getting cheaper air conditioners then in terms of noise level, and other features would be as what you pay. yeah?


New Member
Allbest quoted me the Mit sys 4 inverter at $3.3K, including bracket and installation. Anyone knows how much is the Daikin R410?


Hi david ong,

i must say that its a super duper feat to cool the room given the limitation of 8.5amps. yours is an old estate is it?

Phew let me count ah
MBR should require at least 10,154 BTU
BR 1 and 2 should require at least 9826 BTU each.
Living dining should require around 27,623 BTU,

and given your limitations of 8.5amps. i must warn you that if you operate all at the same time all the rooms will be just superficially cool, NOT COLD.

Cos as it is you would need to get an inverter system with the following configuration.

MXY-4A38VA (for this compressor its bigger than the normal ones and hence if your window height etc you would not be able to get this and this has a high BTU capacity, plus getting this combination is really expensive.

MSXY-GA10VA x 2 for Bedroom 1 and 2
MSXY-GA13VA x 1 for MBR.
MSXY-GA26VA x 1 for hall

With the above combination will set you back around $4,693.50

and if you operate simultaneously then the mex capacity that will be able to be generated is as follows
4367 BTU ffor each of the Rm1 n 2
6141 BTU for MBR
12 419 BTU for hall,

this is far cry from your actual need. I mean technically it can still sorta cool all the rooms but you would need to ensure like the curtains are all down and in the hall maybe a fan would be great to help circulate the cool air around faster, and ensure that the

However if your installation place for the condenser does not allow for this extra big condenser unit then you would have to opt for the smaller one as follows

MSXY-GA10VA x 2 for Bedroom 1 and 2
MSXY-GA13VA x 1 for MBR.
MSXY-GA26VA x 1 for hall
this combination would set you back by around $4,084.50

and the cooling capacity would be as follows
4094 BTU ffor each of the Rm1 n 2
5732 BTU for MBR
11 669 BTU for hall

this combination would even be far away from the demands. hence it would take even longer to cool the room.

because your hall is very huge i would urge you not to operate more than 1 hall and 1 room at the same time. this should be the max.

however operating all 3rooms at the same time is not much of a problem as the BTU it can produce to cool is not too far off from the requirements yeah


hi d3.

for daiking r410 for their system 4 they run to above 4k which combination are you looking at. personally i would have wanted to get the r410 about a year ago but it was far too expensive ler thus i got the r22 but the flatmate series.

no regrets cos mine's a daikin hahahaha


New Member
Hi Ridz,

very confused by the BTU. e.g. you say at top of message that BR1 is 9826 BTU. Then at bottom, you said BR1 is 4094 BTU for cooling capacity. They are diff?

So the $3.3k quote from Allbest is of a lower capacity? I think it is 9-9-9-28 for the blower.

So if I get the MXY-4A38VA, it will be able to cool all 4 rooms not cold!!

Thanks for your kind advise.


hi d3,

Read my post again.
The first set of figures that i gave you is POWER REQUIREMENTS means these figures would indicate to you at least that amount of BTU is needed to cool down the room.

Then the second set of numbers is should you opt for the MXY 4a38VA compressor, those would be the capacity that the air con can produce. which you will then notice that what it can provide is a lot lesser than waht YOU REQUIRE.

then the last set of figures is that of if you get the mxy 4a28VA compressor yeah? and if you compare the cooling that the air con system can provide you is even lesser than what that of what the 38va can produce for you when running simultaneously.

yes either way IF YOU TAKE THE 38VA the 28VA your rooms will not be cold but more cool. because of the sheer size and of course the limitatations of the 8.5 running amps.

from waht i think the 3.3k quote should be indicating a 9+9+9+26 with the 28VA compressor right?

for the MBR i would say that its safer to have a 13 for the mbr but this is my opinion yeah you can still take the 9k blower i dun think it would cause much of a problem.

and of course if you can do take the 38VA compressor. but then again i must urge you to think carefully what would your exact needs be. is it to cool the 3 rooms most of the time or all 4 rooms to be on at the same time? cos then would you be able to weigh out if its worth it to spend that extra money to get the 38va instead of the 28/


New Member
Hi Ridz,

Okay, I understand now. Tks.

Earlier, I had wrote to HDB telling them my concern that one compressor to cool 4 rooms with 8.5A limitation is not possible. I had wanted to buy one sys 3 and one sys 2. They told me that they don't limit the number of compressors, but the current. But it is the same thing, rite? So I ask if I can apply for an additional power point for air con, say 20A. Then they suggest me to call a rep from Daikin that can help me. I have not contacted him yet.

Maybe use 2 non inverter compressors, can?

Ridz, how to calculate capacity in terms of current?


hi D3,

just to check with you what types of housing are you staying in?

is it maisonette?

Reason why i am asking is you is because like say HDB 4 room which i am staying which is an old block i can only put the compressor outside by MBR and no where else hence i am so called limited to just one compressor. while say in the case of maisonette i think you can fix 2 or so cos there is spave that you can do that.

check with HDB again for your address how many approved locations can you use to put condensing unit.

But the limitation would then be that of the total running current. and air con would be limited to 8.5amps only/

unlike in new houses where the supply of electricity is 40 amps their air con limitation is 11 amps and im sure with 11amps limitation the mitsubishi 28VA would do slightly better but the 38VA would do even better closer to the requirements.

well of course if hdb says can then you can get 2 non inverter compressors cos usually system 3 does not exceed the 8.5amps operations mark. but for the system 2 depends it might not be as powerful as inverter with 8.5 amps operation yeah?

and lastly what you mean calculate capacity interms of current i dun get you.


New Member
Hi Ridz,

It is a 5I point block in AMK, 26 years old. I classify the living/dining as one room, lah.

I re-read the letter from HDB. Actually, I can apply for another new air-con point, thru an EMA licensed worker. So I will have 2 air con point, rite? Then I can use 2 compressors rite? Heard of such cases in HDB history they will approve?


New Member
Hi Ridz,

I mean how do we know we are exceeding the 8.5A limit by looking at BTUs. HDB spec say 8.5A and air con vendors ratings are in BTU, it is not matching. Why can't they say, e.g. this compressor uses 9A at max load or 3 HDB room size.


Hi D3,

One thing at a time yeah, yours is a 5 room flat huh. does it have a balcony?

If yes then probably chances are higher you might be approved to have 2 compressor to be placed in the balcony area.

If you dun have then i can tell chances are NIL. I havent heard of any HDB though to have 2 compressors approved for fittin.

yes you can have additional air con point. as air con points are taken as somewhat similar to just another electrical point. you can have as many point as you want but total once again cannot exceed the limit of 30amps yeah?

But having another electrical point does not equate to approval to have 2 condenser in the house.

I think you might wanna try to ask them in a manner that where are the approved locations that you may place your condensing unit. if its just one place then you have only that one condensing unit. igf they say for your floorplan you can place it A snd location B then good for you, can install 2 but so far i havent heard any lah 2 compressors in a hdb.

And for the 8.5amps. you have to check the Engineering data of the respective companies. AKA the catalogues of the various air con.

Why is there such a disparity is as follows:

Say a system 3 both inverter and non inverter the electricity requirements for the compressor to be able to produce its maximum capacity usually is in the lingering of around 8.5amps.

However when you come to system 4 yes then thats where the problem begins.

Typicall more units attached to one condensing unit more electricity is needed for the compressor to run to maximum power which usually means around 11amps to run all 4 rooms.

However this is the difference with inverter and non inverter.

With non inverter once compressor is on it will go jump up to maximum usage and in the case of non inverter system 4 it will jump up to 11amps. and once temperature is reached it will off the compressor and it will go down all the way to almost zero, so only if your apartment has a loading of higher electrical supple then you can operate an 11amps sytem

with INverter system however because of the nature of how it works, This is what inverter will do when you switch on. it will slowly pick up its speed slowly invreasing its power and raising it to the maximum and once temperature is reached it will run to a minimum but continue to run the compressor to maintain the temperature yeah.

Inverter system is controlled more precisely by a powerful chip and that chip you can program it to only use up to 8.5amps max.

However there is a downside to this. lower running amps would translate to lower cooling capacity.

Now this may seem bad but dun forget inverter is smart it can redistribute the coolin capacity around the rooms to cool.

i give youi example

ROOm A not cold not 'on' then you turn on, Room B also not Cold not on then you turn on also and Room C is already on and its Cold.

take it that room a is a compressor by itself while room b and c share another compressor

What non inverter does is cos it can only go max or nothing so compressor a will run to max to cool room a and once its cooled it will stop.

Second compressor however will now have to share and they share in a fixed manner such that if room C is cold but room B is hot the compressor is still running at maximum.

and also if say room A is cold but room B not cold, because of its either on or off and fixed distribution compressor A cannot run to help room B to cool faster (since room B is sharing cooling capacity with room C)

In the case of an inverter this is what will happen
ROOm A not cold not 'on' then you turn on, Room B also not Cold not on then you turn on also and Room C is already on and its Cold
All 3 rooms will share only ONE compressor,

so what will happen is that instead of supply room C all of the capacity what it does it will supply room C with just enough to maintain temperature and supply the max to both room A and room B until room A and B has been cooled then it will supply minimum to all 3 rooms.

and when it is supplying minimum the compressor speed will slow down and this translates to lower electricity cost to run yeah?

and say you put another room C into service, the compressor will then run up maximum (notice that when compressor is maximum the cooling capacity is not fixed when its sent to the respective indoor units but its efficiently distributed to where its needed) then send whatever balace of the capacity its capable to room C to cool that room while maintaining the other 3 rooms.

So yeah can understand?

also also NON inverter system you cannot add like say i want system 3 with 9+9+18 no such combinations allowed.

But with inverter cos its smart distribution system so tou can have like funnyt configurations like 9+18+22 or something like that


hi D3,

also with regards t your this question

mean how do we know we are exceeding the 8.5A limit by looking at BTUs. HDB spec say 8.5A and air con vendors ratings are in BTU, it is not matching. Why can't they say, e.g. this compressor uses 9A at max load or 3 HDB room size.

well why not using BTU is because although that would be easier,

typically a NON inverter system 3 maximum BTU they can give is 20,500

while Inverter system 3 can give maximum BTU of 24,000

so then how?

like system 4, non inverter can give like maximum of 25,600 BTU and this runnig at 11amps

while an inverter running on 11amps can produce maximum of 32,823 BTU

so yeah see the difference?


New Member
Hi Ridz,

I have a balcony. Perhaps I can put one in he balcony and one outside the flat. 2 in balcony would be ugly? 2 outside the flat would be ideal, but I doubt they will allow. Anyway, I will ask them the compressor layout for my flat.


yeah perhaps you could do that,

just check with them yeah.

and as for operating all the 4. even though mine is a 4 room flat with 3 bedroom and a hall system 4

i can say that when running all the systems together its kinda a bit cooler almost to cold but that is because my hall requirements is 13000 btu and my rooms needs barely 7000 btu each hence my daikin compressor which can provide max 25000btu can still handle it.

but when i have guest like that other time during festivities i tell you its like just cool for comfort as in sorta dry and cooling but not cold yeah.

and especially with yours imagine 57249 BTU but the max if say you are taking the 38VA can produce is 27296BTU and this is barely half of your entire requirement especially with 8.5 limitation yeah.


New Member
Hi ridz...can I ask u for some opinions too? I'm planning for a system-2 for 2 bedrms (mine is a resale 3rm flat) which brand would u recommend and should I go for inverter kind? I dun think we will on the aircon everyday, prob only once a while.... Thanks in advance


hi cookie,

just a question would you want to air condition your hall as well?

how big is your hall? hmm cos i think the prices for system 2 and 3 are pretty close.

i think for your usage probable non inverter would be sufficient


New Member
not planning for hall, jz the 2 rooms. Which brand is energy saving and easy to maintain huh? is it the mitsubishi? Thanks so much!


New Member
Hi Ridz,

I was wondering if I put 2 units in the living room and one each in MBR and BR1 for sys 4. Then I buy a window unit with 13A plug for BR2. Is it feasible with 8.5A limit?


i think that shold be okay,

however if you are thinking of operating like an oven while switching on the entire house's air con then be careful might trip.

but other wise i think its alright

do note though that if you are using the window unit the electricity consumption is that really as efficient as split type models.

Split types models dun consume that much electricity as compared to window type and they are not as good in the distribution of air. you might want to take note.


oh yeah and i one thing to add would be is it really necessary that will come to a time where the hall will be utilised at the same time with the rooms?

if not then yes just a system 4 would be able to do the job for your hall..

can give me more details of your usage of each of the rooms. and time of day and duration please?

then we can see waht are the chances of simultaneously having all the rooms to be cooled at the same time


hi cookie,

well the answer to inverter or non inverter depends highly on your usage,

it would be best if you would be able to give me a projection of how many days say in a week would you operate the air con? and also for how many hours and which rooms is it just one or both?

then only can i answer inverter or non inverter.

as for energy saving well mitsubishi and daikin you can consider. also maybe toshiba perhaps or something to that extend. we will come to that shortly.

cos the budget also if you woulf please state. then will narrow down a lot of brands.


New Member
Anyone who have installed casement aircon before? How is it? Is it very bulky type? We installed system 2 when we renovated the house thinking that we may not need it and to save money. Now that we want to install one more, it is not cost effective to have additional blower as they need to change the system 2 to system 3 and hence advise to buy the casement.
Anyone in the same situation?


New Member
hi ridz, we will probably on the aicon say once a week for 6 hrs? And likely on for one bedrm only, won't on the aircon for both rms at the same time cos' we dun have kids (won't have for another 2 yrs at least).

Budget wise, I dunno market rate leh, less than $1.5k have?


New Member
Hi Ridz,

HDB told me to go to their website to know where the location of the external unit. They also told me that even if I applied for another aircon point, I have to maintain the 8.5A limit. So after further consideration, I have decided not to install air con in the living/dining area. I am on the 25th floor, so it may not be so bad, else hide in the rooms.

Pls advise what is the best value for a non inverter system 3 for my unit. I re-attached the size you calculated previously:-

MBR should require at least 10,154 BTU
BR 1 and 2 should require at least 9826 BTU each.


Hi cookie,

I would think that with your usage with once a week a non inverter system. Then now depends on your brand preference lor such as the features of different brands

Give you an idea how much they cost yeah?
42CNMR010 (QTY:2 )
68CNMR218 (QTY:1 )(this im not too sure but i think its the millenium series)
Price :$1,323.00

MA45EV1 (QTY:1 )
FT25DVM (QTY:2 ) (flatmate series)
Price : $1,365.00

CU-2C18EKH (QTY:1 )
Price : $1,480.50

SAP-CM1823G (QTY:1 )
Price: $1,512.00

Just a rough idea. But what features would you want to have. And also just to confirm not installing the hall right as in the future if you decide then its hard


hi d3,

What is your usage going to be like? for each of these 3 rooms?

So you confirm taking the system 3 non inverter?

If yes here are some of the quotes that i may let you know just as a rough guide.

MA56EV1 (QTY:1 )
FT25DVM (QTY:2 )
FT35DVM (QTY:1 )
Price : $2,079.00

68SQ321 (QTY:1 )
42CJR010 (QTY:3 )
Price : $2,339.40

SAP-CM2033G (QTY:1 )
Price : $2,005.50

These versus the price of inverter (if your usage is relatively high

3MKD75DVM (QTY:1 )
Price : $2,916.90

MXY-3A28VA (QTY:1 )
Price : $2,908.50


New Member
Hi Ridz,

My usage will be low for all 3 rooms. We used fans most of the time unless boi ta han. I thought Toshiba is popular? I have asked my ID to quote. Can recommend me the correct config for it.

Thanks again for your help. Truly amazing stuff you are providing here.


hi d3,

okie so non inverter for toshiba would be as follows
RAS-3M24UAX4 (QTY:1 )
price : $2,298.45

toshiba is relatively popular but not as popular as daikin and carrier.

just to let you know... daikin and carrier commands one of the highest prices for air conditioning but they also have the bigger in terms of market share. why?

ponder over it yeah?

look around condominiums. all over singapore. usually its daikin or carrier. occasionally it would be sanyo but not mostly the first two/


oops sorry that toshiba may not be suitable for you as its runnig current is 10.5 this could be the one

RAS-3M20UAX4 (QTY:1 )