We traveled to Bangkok and had 4 hours at the Suvarnabhumi airport between the flights. Were hoping to find a place to wait it out and found very comfortable transfer lounge with huge reclining chairs, that one can lay on as in the bed. The access to this lounge is for the passengers with any connecting flights, it's located on the 3rd level on the way to gates B1-B6.
There are approx. 25 chairs, the area is quiet, a bit cold from the A/C but still that's much better option to the cold metal chairs elsewhere.