Hi all.. I have a resale flat.. and now thinking to install aircon in 2 of the rooms.. To do that, need to install the pipes, etc right.. If the pipe need to go through walls etc, so who will drill the hole in the wall for the pipe to go through? Is it the aircon-installation man (already inclusive in the aircon price that we pay), or do we need to hire a separate contractor to do so? Also how about the wiring etc? Thanks!