Nice Shin! Shin have you identified any local bat species (insectivorous bats only) which might use your bat house? When and if you do, I'll be eager to hear about it. I wish I could offer further advice on where to mount it for thailand bats but I'm currently ignorant about their preferences. In the USA bat houses need sun exposure ans are more successful when they are out in the open not deep in the woods or beneath tree cover. Will be interested in what you find out. Again nice job and we'll look forward to your feedback when you mount it and thank you for the photos. Shin have your heard of this bat man in Thailand:
Surapon DuangkhaeSurapon currently serves as Projects Manager for the Wildlife Fund of Thailand, overseeing all conservation projects for the country. Some of his recent accomplishments include saving a colony of several hundred thousand insectivorous bats that occupy the attic of the National Museum in Bangkok
http://www.batcon.org/batsmag/v6n3-7.html Estimates suggest [approximately equal to] 112 bat species in Thailand; 18 are fruit bats and
94 are insectivorous bats