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Air conditioning - Any recommendations please??

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Old 09-01-2017, 08:50 AM   #9211
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Hi,

The link show an insulated pipe photo at the FCU. The FCU consist of the evaporation coil with 2 ends, one incoming and another outgoing. The incoming pipe is smaller, carrying liquid refrigerant while the outgoing pipe is larger, carrying refrigerant gas back to the condenser.

Both these pipe are place together in one insulation inside the FCU. It is normal for installer to group both the smaller and larger pipe from the condenser together in one insulation as it get nearer to the FCU to joint to the respective pipes in the FCU that are in one insulation.

It is good practice to observe the installer during installation to ensure that the pipes before this grouping into one insulation are actually individual insulated pipes. This grouping should be as short as possible. There is no standard to date as to the length of this grouping.

The above are my opinion and hope that they are helpful.
i didn't observe during installation

that means i need to ask them open for me to see if it's individually insulated pipes or what?

or can't do anything liao?

but apparently need the different insulation sizes even though my package is 1/2" de? they brought 1/4, 3/8 and 1/2" with them. saying for different sections. is it correct?

Last edited by zzzzzz87; 09-01-2017 at 08:54 AM..
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Old 09-01-2017, 10:24 AM   #9212
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i didn't observe during installation

that means i need to ask them open for me to see if it's individually insulated pipes or what?

or can't do anything liao?

but apparently need the different insulation sizes even though my package is 1/2" de? they brought 1/4, 3/8 and 1/2" with them. saying for different sections. is it correct?
Hi,

You can see whether the pipes are individually insulated at the point the pipes are jointed to the condenser.

But how long is the "grouped" pipes with single insulation at the FCU is some thing that you cannot confirm without opening the cornices. The choice is your but there may be cost incurred.

However, you can also look around those places that the pipes are run and see if you can access to view it (for example insulated pipes above toilet false ceiling are normally exposed, meaning you can see it if you look above the toilet false ceiling) or pipes that are in conduit which you can open the conduit cover to check the pipes. These conduits cover are held in place by snapped on plastic grooves at the sides.

It is not normal to have different insulation thickness along different sections of the pipes. So if you pay for the 1/2" insulation, then it should be 1/2" throughout the full length of each pipes (small and pipe pipes) except when it get nearer to the FCU, when the pipes are grouped together within one insulation (still 1/2" type) to be jointed to the FCU piping.

The above are my opinion and hope that they are helpful.
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Old 09-01-2017, 10:34 AM   #9213
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Hi,

You can see whether the pipes are individually insulated at the point the pipes are jointed to the condenser.

But how long is the "grouped" pipes with single insulation at the FCU is some thing that you cannot confirm without opening the cornices. The choice is your but there may be cost incurred.

However, you can also look around those places that the pipes are run and see if you can access to view it (for example insulated pipes above toilet false ceiling are normally exposed, meaning you can see it if you look above the toilet false ceiling) or pipes that are in conduit which you can open the conduit cover to check the pipes. These conduits cover are held in place by snapped on plastic grooves at the sides.

It is not normal to have different insulation thickness along different sections of the pipes. So if you pay for the 1/2" insulation, then it should be 1/2" throughout the full length of each pipes (small and pipe pipes) except when it get nearer to the FCU, when the pipes are grouped together within one insulation (still 1/2" type) to be jointed to the FCU piping.

The above are my opinion and hope that they are helpful.
do they use the smaller insulation for other purposes then? cuz when i saw 1/4" and 3/8" and 1/2", i asked the worker and that's what he said... hmmm.

mine is just a BTO, system 1 in MBR so the connection is pretty direct, from service yard to master bathroom to master bedroom.

i probably have to go open the toilet false ceiling to check in that case...
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Old 09-01-2017, 10:38 AM   #9214
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do they use the smaller insulation for other purposes then? cuz when i saw 1/4" and 3/8" and 1/2", i asked the worker and that's what he said... hmmm.

mine is just a BTO, system 1 in MBR so the connection is pretty direct, from service yard to master bathroom to master bedroom.

i probably have to go open the toilet false ceiling to check in that case...
They won't use 1/2" insulation for the drainage pipes, as far as I know. I believe those are 1/4" ones instead. Not sure where they'll use the 3/8" ones.
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Old 09-01-2017, 11:06 AM   #9215
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They won't use 1/2" insulation for the drainage pipes, as far as I know. I believe those are 1/4" ones instead. Not sure where they'll use the 3/8" ones.
Yes,

Drainage pipes are not as cold as the copper pipes, so it is normal to have 1/4" insulation. But it can be cold enough to cause water condensation outside the pipe as our humidity is high (about 60+% to 95+% and sometime even 100%) and our dew point also high (about 22 to 27 degree) in Singapore.

So if your water in the drain pipe falls below 27 degree in some days, it is sufficient to cause water condensation outside the pipe, if it is not insulated sufficiently.

Some drainage pipes are run under the floor and if not insulated sufficiently, water condensation may cause water dripping from the ceiling of the unit below. Rectification can be costly if this happened. So there is no harm increasing the insulation at critical place like this one to save expensive repair in future.

3/8" insulation are provided as a standard package by contractors, if I am not wrong.

The above are my opinion and hope that they are helpful.

Last edited by dachee; 09-01-2017 at 12:57 PM..
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Old 09-01-2017, 11:11 AM   #9216
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Yes,

Drainage pipes are not as cool as the copper pipes, so it is normal to have 1/4" insulation. But it can be cold enough to cause water condensation outside the pipe as our humidity is high (about 60+% to 95+% and sometime even 100%) and our dew point also high (about 22 to 27 degree) in Singapore.

So if your water in the drain pipe falls below 27 degree in some days, it is sufficient to cause water condensation outside the pipe, if it is not insulated sufficiently.

Some drainage pipes are run under the floor and if not insulated sufficient, water condensation may cause water dripping from the ceiling of the unit below. Rectification can be costly if this happened. So there is no harm increasing the insulation at critical place like this one to save expensive repair in future.

3/8" insulation are provided as a standard package that contractors, if I am not wrong.

The above are my opinion and hope that they are helpful.
Fortuna quoted me with 1/4" insulation for my drainage pipes. Hmm. Worth a clarification with the boss when he/she comes by.
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Old 09-01-2017, 11:20 AM   #9217
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oh.... i clarified with them already. paiseh to all.

Armaflex class 1 H (1/4 “) - 1/4" is the hole of insulation, not thickness of insulation

the H is 1/2" thickness of insulation
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Old 09-01-2017, 12:37 PM   #9218
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Usually drainage pipe is 1/4 thickness by default.


Fortuna quoted me with 1/4" insulation for my drainage pipes. Hmm. Worth a clarification with the boss when he/she comes by.
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Old 09-01-2017, 12:53 PM   #9219
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Fortuna quoted me with 1/4" insulation for my drainage pipes. Hmm. Worth a clarification with the boss when he/she comes by.
Hi,

What I mend about the 3/8" insulation is that it is in the standard package of the copper pipes. Not the drainage pipe.

Hope that this clarify any misunderstanding.

BTW, 1/4" insulation for drainage pipes is normal practice. Unless you decide to improve it as a safety factor.

Last edited by dachee; 09-01-2017 at 01:12 PM..
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Old 09-01-2017, 12:55 PM   #9220
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Usually drainage pipe is 1/4 thickness by default.
Yes. This is correct.
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Old 09-01-2017, 01:08 PM   #9221
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They are not managed by Daikin.
They are authorised dealers of Daikin.


Is it advisable to use the daikin pro shop for purchasing and installation? Have to decide on aircon soon since my renovations are staring.

Any difference between the different pro shops? Are they manage by daikin directly or are they sub cons?
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Old 09-01-2017, 05:18 PM   #9222
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Am having the aircon installation this friday.

So i need to look out for these few things:
1. Insist on flared joint for joining pipes when there are requirements for piping more than 15m.
2. Separate insulation for piping away from the FCUs.

Anything else that i need to look out for?
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Old 09-01-2017, 10:32 PM   #9223
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Am having the aircon installation this friday.

So i need to look out for these few things:
1. Insist on flared joint for joining pipes when there are requirements for piping more than 15m.
2. Separate insulation for piping away from the FCUs.

Anything else that i need to look out for?
The height of the FCU?

I seen lot of renovation pictures, all FCU mounted to the highest point which is not recommended.
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Old 10-01-2017, 02:23 AM   #9224
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Hi,

In my opinion, your living room area after the removal of the study room is estimated to have an area of 50m2. Taking your ceiling height as 2.8m and temperature difference of 10 degree C, your required Btu is less than 18k Btu. (slightly above 10k Btu).

The MXY-3G28VA is a system 3 condenser, meaning it allows 3 FCUs to be connected to it. And it provides up to a normal capacity of 6kW or 20k Btu. and a max of 8.9kW or 30k Btu. In this case, as you are not installing 3 FCUs (you only need 2 FCUs), you are not using the condenser as it is designed for. However, you are paying for the extra features.

Furthermore, this 20k Btu normal capacity (max. 30k Btu) condenser is above your living room cooling requirement.

In my opinion, it would be good enough to have MXY-2G20VA with normal capacity of 4.8kW or 16k Btu (max 6.3kW or 21.5k Btu) and 2 MSXY-FJ13VE with a 3.5kW each or 11.9k Btu. This will allow you to adjust different coolness for different section when required.

Having a MXY-3G28VA and MSXY-FJ10VE + MSXY-FJ18VE does not allow you to do this.

It will be good if you can place a barrier between the living room (or dinning room) and the kitchen to avoid heat from the kitchen heating up your living room and higher running cost.

If you are still concern about the cooling capacity and capacity of the condenser and FCU selection, you may wish to visit Mitsubishi Electric technical support at their Alexander Road office for advise.

The above are my opinion and hope that they are helpful.
if i use 2 x ge24va fcu + 4a38va compressor the max cooling capacity each fcu is 4.40 kW, total cooling capacity 9.20 kW 31k btu, do you know why it doesn't provide 38k btu ?
the catalogue doesn't specifiy max kW when using 1 ge24va either.

so it looks i would need 4 x ge10va to get 11.20 kW?


how about the 5 ticks daikin mks90qvmg 43k btu, mitsubishi 5g48va 46k btu do they have the same issue?

if its via 5 fcu then i have to move a lot of stuff to install 5 fcu in the living room, and divide 5 fcu between the 3 bedrooms.
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Old 10-01-2017, 09:31 AM   #9225
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The height of the FCU?

I seen lot of renovation pictures, all FCU mounted to the highest point which is not recommended.
Hi,

Any recommendations on how high the FCU should be? My current FCU is just below the cornices...

Thanks.
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