I was thinking that for this application, the water could be cycled through hot water tank. A 1/4hp circulating pump and a check valve would accomplish a very simple tie in.
Oil or glycol would be ideal if you wanted to heat underneath the unit, in the winter.
990SMT, 640A, TXC450, TE510, ATC350X, ATC200ES, 550MXC, BW200. Need more space in garage.