I have to buy 2 airco units. One for living room and one for bed room.

For a good calculation one need to know the general insulation status of the room, like glas surface, wall material and ceiling insulation. 

 

Living room is 4x8x2.6 mtr,ceiling insulated with 150 mm rockwool+alu foil, long wall outside no sun next to carport with 2 windows single darkend glass pane 4square mtr. Short wall a litlle sun in evening with single glass sliding door 8 square mtr. Other walls bedrooms and kitchen.

 

Bedroom is 4x4 mtr ceiling insulated with 150 mm rockwool+alu foil, 1 wall litll sun in evening with 1 window single darkend glass pane 2 square mtr. Other wall No sun with 1 window single darkend glass pane 2 square mtr. Other walls inside.

All walls are Q-block 8 cm double plastered.

 

Please can someone advice me about the nessecary BTU's?

And if possible the used calculations to help me in future?

 

Great Thanks in Advance

Max

I'm no specialist but I would go for something that has extra BTU rather the opposite.

 

An undersized unit with regard to the space may constantly be on max power to attain the required temperature and by what other more knowledgealbe then myself have said here, it's not a good choice to have a under rated BTU unit.

 

The site below has a chart that references the surface area,  with the required BTU and explains.

 

https://www.omnicalculator.com/construction/air-conditioner-room-size

 

To make it short, the calculation should be as follows (cf. Google)  :

1. Measure the square footage or area in square meters of the room. For that, multiply its length by its width. If using meters, multiply the result by 0.092903.
2. Multiply this by 25 BTU to get your air conditioner size.

 

 

 

Thanks for the OMNI calculator but I am sure this is not suitable for Thailand. This calculator does not take all important variables in to account.

Regards, Max

1 hour ago, Max Brok said:

Thanks for the OMNI calculator but I am sure this is not suitable for Thailand. This calculator does not take all important variables in to account.

Regards, Max

USA, especially the SE gets just as hot & humid as TH, so not sure why you think the calculation wouldn't apply to TH.

 

Copy from a different thread, same topic:

"We have a 13k in the bedroom, 23m², and could easily get by with 9k BTU unit.  House good build material, insulated block & roof/ceiling.  Actually gets damn chilly.

 

We have the 13k, and a 24k BTU unit, which they condition 105m² daily, and do it quite well.  Bedroom & main room, usually leave bedroom door open, though neither room needs supplementing from the other.

 

Mitsubishi Inverter fan myself."

The general Thai guesstimate for A/C sizing is 600-700 BTU per m². It's horribly basic and tends to over-size but with modern inverter A/C over-sizing isn't much of an issue.

 

Your 16m² bedroom would come out at 9,600 - 11,200 BTU, I'd look at the smaller end of that with a well-insulated room.

 

The 32 m² lounge would be 19,200 - 22,400 BTU, again well insulated would tend towards the lower end.

 

Like many things, you can calculate to the n^th digit and then have to pick from a limited range of available values.

 

Definitely go for inverter units for energy savings.