Air Conditioning

[st11x]

G'day,

I'm now renovating and thought about replacing the existing air conditioners since I will have to also install additional ones. I remembered when I was in Singapore, we had mostly split systems - System2/3/4. So I started looking from that angle since having less of the "boxes" outside the house is attractive and frees up more ground space.

However, it seems it is not so popular here. Also, they always tell you separate ones are better because if one goes down, the others are not affected. Do people buy split systems only because they do not have "choice" like in Singapore where people mostly live in high rises and have at most one or two spots outside the flats to install the compressors?

On a similar topic, my bedroom is 18 sq m. It used to have a 13K BTU machine but the contractor says it is not enough. So he has moved it down to the living room which is 51 sq m and have asked me to buy a 18K and a 24K BTU machine for the room and living room respectively. The room has 2 large windows and a glass door that goes out into the balcony. However the air conditioner is mostly going to get used only at night. Is 13K sufficient for the bedroom?

Thanks

Matt

[webfact]

Moved

[trogers]

However the air conditioner is mostly going to get used only at night. Is 13K sufficient for the bedroom?

What is the ceiling height? You are cooling a volume of air space, not just floor area.

Any glass sections facing west?

[st11x]

What is the ceiling height? You are cooling a volume of air space, not just floor area.

Any glass sections facing west?

The height of the ceiling is 2.3m. The large door and one window is facing west, the other is to the south. It is mostly shielded from the afternoon sun because there are a number of trees, but the evening sun still shines through.

thanks

Matt

[fremmel]

A lot also depends on the insulation, if any, you have. I have a 25 sqm bedroom on the SW corner of my house with a 2+ sqm window in both the south and west walls and no shade. A 9 KBTU unit works well for me BUT I have double block outside walls with fiberglass in between, insulation on the ceiling, and a vented attic space with foil under the tiles. If you have typical Thai construction with no insulation anywhere you'll need a lot more. It sounds like your bedroom is on the second floor so if you have no attic insulation you can cut down a lot on the size of the AC you need by adding it. Typically the Thai AC people are used to working with non-insulated spaces so they always specify large units.

It also sounds like you just bought the house so you don't have any experience with whether the room was too hot or not. Any chance to talk to the previous owners and get an idea? Then you'll have a sense of what, if anything, needs to change.

[trogers]

Unless you take naps between 1-3pm, use 15-16k BTU is sufficient for 18m2 room with 2.3m high ceiling. I assume the trees will block off most of the sun rays after 3pm.

The 24k for your 51 m2 living room is insufficient for a hot day. Recommend you use two 18k BTU instead, and you need run only one ac unit during the cooler periods when outside temp is 28-29C.

Avoid multi-split types. Invest in inverter units instead.

[st11x]

Thanks for the replies.

Yes we just bought the place, but the previous owner never lived there. They bought it for rental income and they live just 50 meters down the road, so I am not sure if they can give me any information. I'll ask them the next time I catch hold of them, but that's a good point.

The house is not insulated, but I was thinking of stuffing the fiber thing on the roof. I chanced upon it at GlobalHouse the other day, and it was quite cheap so I thought why not.

Trogers, I don't see many 15-16K BTU machines around. They are usually rated at 8K+ to 9K+, 12K+ to 13K+, 17K+ to 18K+, and then the 24K+ ones. Guess that is why the contractor recommended me the 18K machines too.

The 51 sq m living room already has the old 13K machine from the bedroom, so you are saying it is better to have two 18K than to have a 24K and a 13K?

thanks

Matt

[trogers]

Thanks for the replies.

Yes we just bought the place

I don't see many 15-16K BTU machines around. They are usually rated at 8K+ to 9K+, 12K+ to 13K+, 17K+ to 18K+, and then the 24K+ ones. Guess that is why the contractor recommended me the 18K machines too.

The 51 sq m living room already has the old 13K machine from the bedroom, so you are saying it is better to have two 18K than to have a 24K and a 13K?

I was thinking of Daikin inverter units:

FTKE15GV2S

FTKS18GV2S

http://www.daikin.co.th/product/room_air/fighting.htm

http://www.daikin.co.th/product/room_air/inverter.htm

Since you bought the place and it will be self-occupied for many years to come, better to install new ac units and sell off the old ones.

Here is a photo of my living area with the two 18k BTU units. Room dimensions are 4.5m x 11.5m x 2.9m high, but balcony faces north.

Edited October 12, 2009 by trogers