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Posted

Having searched this forum the Daikin inverter range seems a good choice of air-con.

From the forum I understand there are a lot of variables for choosing an air-con unit for a particular size room. But for 42sqm 30,000 BTU unit may be suitable.

However, the largest daikin inverter unit I could find was the FTKD28GV2S - 23,000 BTU unit.

Do I have to look at another brand or can I use 2 smaller daikin inverter units, eg 1x FTKD18GV2S 18,000 BTU and 1x FTKD15GV2S 14,000 BTU?

If I can use the 2 smaller units, should they be on different walls, or both on the wall above the window?

(The room is a new build studio condo with one glass wall/window leading onto the balcony.)

Posted
Having searched this forum the Daikin inverter range seems a good choice of air-con.

From the forum I understand there are a lot of variables for choosing an air-con unit for a particular size room. But for 42sqm 30,000 BTU unit may be suitable.

However, the largest daikin inverter unit I could find was the FTKD28GV2S - 23,000 BTU unit.

Do I have to look at another brand or can I use 2 smaller daikin inverter units, eg 1x FTKD18GV2S 18,000 BTU and 1x FTKD15GV2S 14,000 BTU?

If I can use the 2 smaller units, should they be on different walls, or both on the wall above the window?

(The room is a new build studio condo with one glass wall/window leading onto the balcony.)

What is the ceiling height? Where is the location to place the condenser unit? One side of the balcony? Which side? At the far end wall or near to the end of your bed?

23,000 BTU is okay for 42m2 with ceiling height of about 2.4m. Bathroom door should be closed when using the air-con as its floor area is about 4m2.

Posted

When you ask at in an experienced aircon shop they will multiply cubic meter of the room with 300 to calculate the needed Btu.These calculations are for a house so they will be slightly lower for a condominium.Yes you can split up in 2 smaller units but you should place them in different areas of the room.I would even prefer to have 2 smaller units instead of 1 bigger unit because in the cooler periods of the year you might have enough cooling with only one unit running and it will spread the cool air better when both are turned on.

p.s.:If you are interested in the samsung inverter aircons,which use the R-410a refrigerant which is the new standard after 2010,at a real bargain price you can pm me.

  • 2 weeks later...
Posted
Having searched this forum the Daikin inverter range seems a good choice of air-con.

From the forum I understand there are a lot of variables for choosing an air-con unit for a particular size room. But for 42sqm 30,000 BTU unit may be suitable.

Crikey, is your ceiling like 100 feet high! :) I think you're going way overboard there with your calculations. That size room works out about 17k BTU, so something like 20 should be fine even with minimal insulation. If you end up going too large thinking it will cool better, it will do so too fast and you'll end up with a bunch of uncomfortable, cool-damp humidity. I know those inverters ramp down the compressor when the room is cooler, but still, no need for the overkill.

Have a 30-odd sqm southwest-facing bedroom with large windows on those sides and only a 9kBTU Mr Slim. Cools really well and never runs flat out. Although in Chiang Mai where it is often cooler than the rest of Thailand, during March/April the heat here is searing and it copes easy.

Those Daikin's are supposed to be really good though.

Posted

We have a 40 sq m combination dining/living room and have a 25,000 btu air con. We live in CM and it is plenty btu's. I feel you won't need anything more than that. Of course all the air con people tell you that you need more, but really. Take if from a few blokes here, 24/25K is plenty.

Posted

HomePro use a quick-and-dirty table to size your aircon, it makes a vast number of assumptions but here it is anyway. These numbers came from a homepro in BKK, they may use a different table up north :)

BTU - - - - - - - Sq Meters

9,000 - - - - - - 9-15

12,000 - - - - - 16-20

18,000 - - - - - 21-30

24,000 - - - - - 31-35

30,000 - - - - - 40-50

36,000 - - - - - 50-55

OR

Floor area (in square metres) X by 600 gives you the size of the aircon (in BTUs).

If you're going to want arctic conditions you'll need the next bigger unit than this table suggests, if you're comfortable being warmer then a smaller unit will be adequate.

Whatever you do, don't think 'bigger is better', a big aircon cycling slowly will not produce the drying effect that helps you feel cooler. Conventional wisdom says you should use two smaller units, particularly if you have a large area to cool.

Posted
HomePro use a quick-and-dirty table to size your aircon, it makes a vast number of assumptions but here it is anyway. These numbers came from a homepro in BKK, they may use a different table up north :)

BTU - - - - - - - Sq Meters

9,000 - - - - - - 9-15

12,000 - - - - - 16-20

18,000 - - - - - 21-30

24,000 - - - - - 31-35

30,000 - - - - - 40-50

36,000 - - - - - 50-55

OR

Floor area (in square metres) X by 600 gives you the size of the aircon (in BTUs).

If you're going to want arctic conditions you'll need the next bigger unit than this table suggests, if you're comfortable being warmer then a smaller unit will be adequate.

Whatever you do, don't think 'bigger is better', a big aircon cycling slowly will not produce the drying effect that helps you feel cooler. Conventional wisdom says you should use two smaller units, particularly if you have a large area to cool.

I would also add - air-con units will lose efficiency as they age, probably about 3-5% per year, depending on how hard they have been run and level of maintenance. So unless you plan to change your air-con unit every 5 years, it is safer to buy a slightly larger unit.

Posted (edited)
HomePro use a quick-and-dirty table to size your aircon, it makes a vast number of assumptions but here it is anyway. These numbers came from a homepro in BKK, they may use a different table up north :D

BTU - - - - - - - Sq Meters

9,000 - - - - - - 9-15

12,000 - - - - - 16-20

18,000 - - - - - 21-30

24,000 - - - - - 31-35

30,000 - - - - - 40-50

36,000 - - - - - 50-55

They must do because Home Pro were the ones who sold us the Mr Slim and said it'd be fine for the sunside bedroom - 21-30 sq m bracket. They also do good markups on cable/bulbs and, well, everything else :)

Edited by jackr
Posted
HomePro use a quick-and-dirty table to size your aircon, it makes a vast number of assumptions but here it is anyway. These numbers came from a homepro in BKK, they may use a different table up north :D

BTU - - - - - - - Sq Meters

9,000 - - - - - - 9-15

12,000 - - - - - 16-20

18,000 - - - - - 21-30

24,000 - - - - - 31-35

30,000 - - - - - 40-50

36,000 - - - - - 50-55

They must do because Home Pro were the ones who sold us the Mr Slim and said it'd be fine for the sunside bedroom - 21-30 sq m bracket. They also do good markups on cable/bulbs and, well, everything else :)

Because Home Pro(fessional liars) say so doesn't mean it is correct.They are very well known for telling everyone what fits best for them.So I assume they had an overstock of 9000 btu aircons or some similar reason. :D

Posted
I would also add - air-con units will lose efficiency as they age, probably about 3-5% per year, depending on how hard they have been run and level of maintenance. So unless you plan to change your air-con unit every 5 years, it is safer to buy a slightly larger unit.

:)

Posted

The O.P. might consider just having one of the units he indicated FTKD28GV2S - 23,000 BTU unit installed and see if it meets his needs. It might not be tough to add a 2nd unit at a later date. If you look at your Daikin sales brochure the FTKD24GV2S has an EER of 11.93 and is rated 5 on the yellow energy sticker. Not so for the

FTKD28GV2S - 23,000 BTU unit. They both have 3/8" liquid piping minim, both the same gas and drain size requirements. The outdoor unit appears to be the same specs. The interior unit I have is the same physical size, but just a tad more quiet according to the specs in the brochure. Look on the Daikin brochure on the slot for "Power Consumption" and compare the two models.

You might also check out the Panasonic Inverter cscu-s24hkt which is a 24K BTU unit. Our Panasonic Inverter cools a very large bedroom (42 square meters with 3.4 meter high ceilings) and it utilizes the newer R-410a refrigerant. We have had zero problems with all three Inverter units since they were installed 15 months ago.

We bought the 3rd size down Daikin Inverter models for rooms not as large as the O.P. 42 square meter room. In my experience the Daikin FTKD18GV2S is quiet enough for a home theater and office application.

It is not what the unit costs to BUY, it is what it costs to KEEP every month. I would hesitate to buy any a/c or appliance that could not qualify for the 5 rating on the yellow sticker. An independent shop might give you a lower total price to purchase and install and might be more responsive to "after the sales" needs including how many "free" cleanings of your Inverter unit. Where I live the price difference on the exact same models was shocking between dealers.

Posted
I would also add - air-con units will lose efficiency as they age, probably about 3-5% per year, depending on how hard they have been run and level of maintenance. So unless you plan to change your air-con unit every 5 years, it is safer to buy a slightly larger unit.

:)

I'm with Dr Naam on this one.

How hard they have been run?

Give me a break! These are machines, each of which is fitted with a low pressure & high pressure cut-out (if they are of any reasonable quality). If these machines operate within the ranges of these detection devices (no tripping), there is no cause for concern. "Installation quality" may play a part in this.

Of course, if the machine is too large, "short cycling" becomes an issue, which can result in a shortened compressor life (due to inadequate motor cooling by the return gas).

Here's a question for all you "air conditioning gurus"...why is the installtion cost of airconditioning (split systems) so cheap in Thailand?

Posted

We are using a 24,000 BTU Panasonic unit in a 40 sqm condo room and it is fully sufficient (however room heads North).

Best Regards

Posted
Here's a question for all you "air conditioning gurus"...why is the installtion cost of airconditioning (split systems) so cheap in Thailand?

Same reason why a Big Mac cost under Bt100.

Posted
Because Home Pro(fessional liars) say so doesn't mean it is correct.They are very well known for telling everyone what fits best for them.So I assume they had an overstock of 9000 btu aircons or some similar reason. :)

I was simply countering the reply. As I say, it is well man enough as I figured it would be by my own calculations.

Oh, and fyi, it was the only Mr Slim in the place and I went right for it as I knew what I wanted and there was no mention of room size on purchasing. The installation guy initially scratched his head when he saw the size of the room but after measuring up said it would be fine.

Posted
I would also add - air-con units will lose efficiency as they age, probably about 3-5% per year, depending on how hard they have been run and level of maintenance. So unless you plan to change your air-con unit every 5 years, it is safer to buy a slightly larger unit.

:)

I'm with Dr Naam on this one.

How hard they have been run?

Give me a break! These are machines, each of which is fitted with a low pressure & high pressure cut-out (if they are of any reasonable quality). If these machines operate within the ranges of these detection devices (no tripping), there is no cause for concern. "Installation quality" may play a part in this.

Of course, if the machine is too large, "short cycling" becomes an issue, which can result in a shortened compressor life (due to inadequate motor cooling by the return gas).

Here's a question for all you "air conditioning gurus"...why is the installtion cost of airconditioning (split systems) so cheap in Thailand?

the OP seems to have mixed up something. it's not that an older aircon loses efficiency if properly maintained but newer units have gained a small percentage of efficiency each year. partly because of technical innovation and usage of different materials for condensers and evaporators and partly by bending the criteria to achieve higher SEER ratings.

installation in Thailand is dàmn cheap for these main reasons:

-extremely low wages and hard soldering of copper piping instead of using expensive automatic couplings.

Posted
I would also add - air-con units will lose efficiency as they age, probably about 3-5% per year, depending on how hard they have been run and level of maintenance. So unless you plan to change your air-con unit every 5 years, it is safer to buy a slightly larger unit.

:)

I'm with Dr Naam on this one.

How hard they have been run?

Give me a break! These are machines, each of which is fitted with a low pressure & high pressure cut-out (if they are of any reasonable quality). If these machines operate within the ranges of these detection devices (no tripping), there is no cause for concern. "Installation quality" may play a part in this.

Of course, if the machine is too large, "short cycling" becomes an issue, which can result in a shortened compressor life (due to inadequate motor cooling by the return gas).

Here's a question for all you "air conditioning gurus"...why is the installtion cost of airconditioning (split systems) so cheap in Thailand?

installation in Thailand is dàmn cheap for these main reasons:

-extremely low wages and hard soldering of copper piping instead of using expensive automatic couplings.

Ok Doc, I can understand the low wages etc but I have watched some air cond techs work at my place of work...they are pretty rough.

Bending of pipework - who cares about kinks?

Flush out new pipework - who cares about dirt or copper shavings?

These guys are of the same calibre as Thai electricians - woeful!

I'd hate to see how they handle a burnt out compressor (electrical motor burn out).

Posted (edited)
I'd hate to see how they handle a burnt out compressor (electrical motor burn out).

What's there to handle? Change the compressor.

Why did it burnt out in the first place? Had used a Mitsubishi for 15 years without compressor issues. Only problem is less efficient airflow through the heat exchanger and increase operation noise.

Edited by trogers
  • 2 weeks later...
Posted
The O.P. might consider just having one of the units he indicated FTKD28GV2S - 23,000 BTU unit installed and see if it meets his needs. It might not be tough to add a 2nd unit at a later date. If you look at your Daikin sales brochure the FTKD24GV2S has an EER of 11.93 and is rated 5 on the yellow energy sticker. Not so for the

FTKD28GV2S - 23,000 BTU unit. They both have 3/8" liquid piping minim, both the same gas and drain size requirements. The outdoor unit appears to be the same specs. The interior unit I have is the same physical size, but just a tad more quiet according to the specs in the brochure. Look on the Daikin brochure on the slot for "Power Consumption" and compare the two models.

FTKD28GV2S was told that to get a yellow sticker it had to go through some sort of approval rating with some body and that Daikin had only just applied for it and will be getting the yellow sticker soon on this model :)

Was told to get one of these for a room 7M * 3.8M and have 20cm Qcon blocks in this bedroom with few windows. Still deciding

  • 1 year later...
Posted

Im building office currently which is 8x7m = 56 sqm and room height is 2.7m.

Questions, should I got with 2x18 BTU/s or one monster size.... ? if so how big?? 32, 36 ?

Office and residential differ in one aspect. Heat load from number of human using the space. Also, any large glass windows that will bring in light and the afternoon heat?

Posted

People normally install over-sized air con units. Besides being a waste of money, the area stays damp but cold.

My bedroom is 18 square meters and is cooled with a 9,000 BTU unit. The windows are a poor fit and there is no insulation. The 9,000 BTU unit dehumidifies and feels cool despite the unit being on the small side. If I ever replace the unit, it will be another 9,000 BTU unit.

People often do their best to complicate things. For instance, ceiling height may be a big factor when heating a room but is not very important when cooling a room. Heat rises.

If I had a very large area, I'd put in two smaller units and use the second unit only when it is super hot.

Posted

People normally install over-sized air con units. Besides being a waste of money, the area stays damp but cold.

My bedroom is 18 square meters and is cooled with a 9,000 BTU unit. The windows are a poor fit and there is no insulation. The 9,000 BTU unit dehumidifies and feels cool despite the unit being on the small side. If I ever replace the unit, it will be another 9,000 BTU unit.

People often do their best to complicate things. For instance, ceiling height may be a big factor when heating a room but is not very important when cooling a room. Heat rises.

If I had a very large area, I'd put in two smaller units and use the second unit only when it is super hot.

Try sitting 8 people into this bedroom with the door constantly being opened and closed and see if even a 12,000 BTU unit is of sufficient size...lol.

Posted

People normally install over-sized air con units. Besides being a waste of money, the area stays damp but cold.

My bedroom is 18 square meters and is cooled with a 9,000 BTU unit. The windows are a poor fit and there is no insulation. The 9,000 BTU unit dehumidifies and feels cool despite the unit being on the small side. If I ever replace the unit, it will be another 9,000 BTU unit.

People often do their best to complicate things. For instance, ceiling height may be a big factor when heating a room but is not very important when cooling a room. Heat rises.

If I had a very large area, I'd put in two smaller units and use the second unit only when it is super hot.

Try sitting 8 people into this bedroom with the door constantly being opened and closed and see if even a 12,000 BTU unit is of sufficient size...lol.

My wife is not broad minded enough for me to have orgies, so it's just the two of us. If I were able to organize orgies, I'd just install another unit and use it on those occasions.

Posted

People normally install over-sized air con units. Besides being a waste of money, the area stays damp but cold.

My bedroom is 18 square meters and is cooled with a 9,000 BTU unit. The windows are a poor fit and there is no insulation. The 9,000 BTU unit dehumidifies and feels cool despite the unit being on the small side. If I ever replace the unit, it will be another 9,000 BTU unit.

People often do their best to complicate things. For instance, ceiling height may be a big factor when heating a room but is not very important when cooling a room. Heat rises.

If I had a very large area, I'd put in two smaller units and use the second unit only when it is super hot.

Try sitting 8 people into this bedroom with the door constantly being opened and closed and see if even a 12,000 BTU unit is of sufficient size...lol.

My wife is not broad minded enough for me to have orgies, so it's just the two of us. If I were able to organize orgies, I'd just install another unit and use it on those occasions.

Then I would partition up a 20+ sqm space (with a sliding door) for two people and install a 15.000 BTU inverter unit. If you need to show a few more working tables, they can be placed outside in the 30+ sqm portion.

Posted

I think that I would agree with Trogers' post #2 in the sense that the heat exchangers get dirty over time and work less efficiently. I there is a huge difference between the cooling power of a dirty and a clean aircon, but the gunk builds up over time and one can never get the things as clean as they are when new.

Posted

Im building office currently which is 8x7m = 56 sqm and room height is 2.7m.

Questions, should I got with 2x18 BTU/s or one monster size.... ? if so how big?? 32, 36 ?

Office and residential differ in one aspect. Heat load from number of human using the space. Also, any large glass windows that will bring in light and the afternoon heat?

Good note....

I will have around 8 people there all with computers.... It has 2.4m x 2.1m glass sliding doors, 6 windows which do not get much direct sunlight, barely any actually. The doors will get direct sunlight for about 2 hrs from 3-5pm other wise the sun is blocked by big trees. I do not have clients coming so the door is not constantly opened, but with so many people its probably more than in residential apartment which do not have orgies going on =)

I just noticed that for my surprise the price / BTU is cheaper with smaller units (some quick notes under from different options I have been thinking).

2x12,000 BTU Panasonic - 12,620 THB / pcs = 25,240 THB (1,051 THB per 1,000 BTU)

2x18,000 BTU Samsung - 22,900 THB / pcs = 45,800 THB (1,272 THB per 1,000 BTU)

1x24,000 BTU Samsung - 30,900 THB / pcs = 30,900 THB (1,288 THB per 1,000 BTU)

Any recommendations.... would that 2x12,000 be enough?

Posted (edited)

Im building office currently which is 8x7m = 56 sqm and room height is 2.7m.

Questions, should I got with 2x18 BTU/s or one monster size.... ? if so how big?? 32, 36 ?

Office and residential differ in one aspect. Heat load from number of human using the space. Also, any large glass windows that will bring in light and the afternoon heat?

Good note....

I will have around 8 people there all with computers.... It has 2.4m x 2.1m glass sliding doors, 6 windows which do not get much direct sunlight, barely any actually. The doors will get direct sunlight for about 2 hrs from 3-5pm other wise the sun is blocked by big trees. I do not have clients coming so the door is not constantly opened, but with so many people its probably more than in residential apartment which do not have orgies going on =)

I just noticed that for my surprise the price / BTU is cheaper with smaller units (some quick notes under from different options I have been thinking).

2x12,000 BTU Panasonic - 12,620 THB / pcs = 25,240 THB (1,051 THB per 1,000 BTU)

2x18,000 BTU Samsung - 22,900 THB / pcs = 45,800 THB (1,272 THB per 1,000 BTU)

1x24,000 BTU Samsung - 30,900 THB / pcs = 30,900 THB (1,288 THB per 1,000 BTU)

Any recommendations.... would that 2x12,000 be enough?

I would go with 2 x 18,000BTU and 1 x 12,000BTU. You can vary combination in using the 3 A/C units to suit both the hot season when temp rises above 33C and cold when temp peaks in the 20s.

Edited by trogers
Posted

Im building office currently which is 8x7m = 56 sqm and room height is 2.7m.

Questions, should I got with 2x18 BTU/s or one monster size.... ? if so how big?? 32, 36 ?

Office and residential differ in one aspect. Heat load from number of human using the space. Also, any large glass windows that will bring in light and the afternoon heat?

Good note....

I will have around 8 people there all with computers.... It has 2.4m x 2.1m glass sliding doors, 6 windows which do not get much direct sunlight, barely any actually. The doors will get direct sunlight for about 2 hrs from 3-5pm other wise the sun is blocked by big trees. I do not have clients coming so the door is not constantly opened, but with so many people its probably more than in residential apartment which do not have orgies going on =)

I just noticed that for my surprise the price / BTU is cheaper with smaller units (some quick notes under from different options I have been thinking).

2x12,000 BTU Panasonic - 12,620 THB / pcs = 25,240 THB (1,051 THB per 1,000 BTU)

2x18,000 BTU Samsung - 22,900 THB / pcs = 45,800 THB (1,272 THB per 1,000 BTU)

1x24,000 BTU Samsung - 30,900 THB / pcs = 30,900 THB (1,288 THB per 1,000 BTU)

Any recommendations.... would that 2x12,000 be enough?

I would go with 2 x 18,000BTU and 1 x 12,000BTU. You can vary combination in using the 3 A/C units to suit both the hot season when temp rises above 33C and cold when temp peaks in the 20s.

hmm that would be 48,000 BTU ?? I think that is a bit overdoing it as 36,000 BTU should be enough ??

Posted

Im building office currently which is 8x7m = 56 sqm and room height is 2.7m.

Questions, should I got with 2x18 BTU/s or one monster size.... ? if so how big?? 32, 36 ?

Good note....

I will have around 8 people there all with computers.... It has 2.4m x 2.1m glass sliding doors, 6 windows which do not get much direct sunlight, barely any actually. The doors will get direct sunlight for about 2 hrs from 3-5pm other wise the sun is blocked by big trees. I do not have clients coming so the door is not constantly opened, but with so many people its probably more than in residential apartment which do not have orgies going on =)

I just noticed that for my surprise the price / BTU is cheaper with smaller units (some quick notes under from different options I have been thinking).

2x12,000 BTU Panasonic - 12,620 THB / pcs = 25,240 THB (1,051 THB per 1,000 BTU)

2x18,000 BTU Samsung - 22,900 THB / pcs = 45,800 THB (1,272 THB per 1,000 BTU)

1x24,000 BTU Samsung - 30,900 THB / pcs = 30,900 THB (1,288 THB per 1,000 BTU)

Any recommendations.... would that 2x12,000 be enough?

I would go with 2 x 18,000BTU and 1 x 12,000BTU. You can vary combination in using the 3 A/C units to suit both the hot season when temp rises above 33C and cold when temp peaks in the 20s.

hmm that would be 48,000 BTU ?? I think that is a bit overdoing it as 36,000 BTU should be enough ??

My estimate is that 36,000 BTU would not be enough to bring room temp to 25C when outside air is at 36-38C during the hot season, esp when you are sitting 8 in the room. And 36,000BTU is too much during the cool season while 18,000 BTU is too little.

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