what size air con unit should I install

[ghworker2010]

Room size is 

6m x 3.8 wide x 3.3 high

 

what btu should I install

[beachproperty]

9000 btu should be fine......google  6m x 4m for room size and ask how big air conditioner= 9000 btu

[Crossy]

Room is 22.8 m² 

 

Standard Thai guesstimate is 600 - 700 BTU per m² 

 

This gives 13,600 - 16,000 BTU.

 

If it's a bedroom and you don't need arctic conditions you can go smaller. If it's a living room with outside walls and lots of glass then the upper end of the range is where you need.

 

[Kwasaki]

I might start with room size then make judgement how hot the room get in it's position in the house.

Our upstairs bedroom gets sun all day, it had a 9 btu initially but took a long time to cool the room in very hot times of the year like present, replacing it an 18 btu made a big difference, lecky bills cheaper to. 

[ghworker2010]

23 minutes ago, Kwasaki said:

I might start with room size then make judgement how hot the room get in it's position in the house.

Our upstairs bedroom gets sun all day, it had a 9 btu initially but took a long time to cool the room in very hot times of the year like present, replacing it an 18 btu made a big difference, lecky bills cheaper to. 

are you saying that the higher btu machine resulted in cheaper bills? Why is that? Is the higher btu machine more electricity efficient Or is it bc you use it less that the smaller machine?

[Kwasaki]

24 minutes ago, ghworker2010 said:

are you saying that the higher btu machine resulted in cheaper bills? Why is that? Is the higher btu machine more electricity efficient Or is it bc you use it less that the smaller machine?

Yes and Yes has turned out that way, I switch a/c on 15 mins in the room before going to bed.

As I said the upstairs bedroom get hot, faces South and curtained windows all around, I am gonna double glaze em if it's gong to keep being hot like this year.

I insulated the ceiling when we had the 9 btu it made a difference but in the very hot nights it would be on all the time whereas the 18 btu being bigger unit once the rooms cool it just kicks in and out from time to time. 

[mogandave]

are you saying that the higher btu machine resulted in cheaper bills? Why is that? Is the higher btu machine more electricity efficient Or is it bc you use it less that the smaller machine?

Whether the unit is small or large, the same amount of work (for lack of a better term) has to be done to cool the the room.

The small unit is fully loaded constantly, while the larger unit cools the room quickly and cycles off, or in the case of an inverter, slows down.

If you do buy an undersized unit, do not buy an inverter as there will be no benefit with the unit running wide open.