Put a 240 in for your chiller! I don't think you can put a drain in because the slab is already poured. Seal everything so you don't get water going through the walls under the baseboards. KILLZ KILLZ KILLZ wood grows mold fairly easily. Look into getting a water hookup in there at one the end of the room so your top off is out of the way. Try and take your time here because it's BIG! OHHH instead of a chiller, maybe you should solar tube it! Oh and get the dedicated circuits at 20A; The 240 @ 30A (if you get it ).