how much BTU unit I need for a 24 square meter room ?

sales persons seem always try to sell you much more than you need...

currently have a noise compressor which i assume is way to big for the room

wife does not mind, she can sleep, but the zeew zeew zeew is driving me insane...

specially it kinda vibrates all over the house, even in other rooms

is there any thai or english website that tells you exactly what you need for a certain square meter room ?

any advice, tips, website very much appreciated

Remember, google is your FRIEND. Check online theres thousands of sites that offer this sort on info, here i will help.

http://www.csgnetwork.com/acroomsizecalc.html

getting a unit too big for the room is bad and the reasons for that are explained on many of these sites as well.

Good luck and consider an inverter unit, they MAY save you considerable money in the long run.