17 Ant S1's running stable from home.  I anticipate I can add 40 more with no issues (but will probably start to pick up some s3's as well).

For a number of reasons I constructed a 3 sided 'double-pane glass room within an air conditioned glass sun room I use as a home office.  I have an exhaust fan which dumps heat directly outside and use dedicated 240 circuits to power the ants.  I can expand by tapping 2 additional 60 amp 240 services I recently ran for AC and a non-existent hot-tub.  The sub room remains at 'acceptable heat as long as the main room is kept to a max of 90 F.  Directly cooling ant-miners is a loosing battle and costs $.  My experience is that the only way to run lots of ants together is by dumping the heat outside as quickly as possible.