3 ton 120 Vac HVAC ain't out there to the best of my knowledge. There simply is no mass market for it.

Off the top of my head the largest 120 Vac compressors available will be found in big window units, marine and RV applications

Marine heat pumps (equipment designed for use in mid-sized yachts) are generally water cooled (boats float in a very very large source for open loop). Moreover, they are often 120 Vac since boat generators and shorepower hookups are generally only 120 Vac.


My limited experience with them (a 1 ton heat pump aboard a towboat) suggests they are pricey and noisy and not particularly efficient since folks with yachts large enough for multi-ton HVAC aren't especially thrifty.

Even larger yachts tend toward central chillers and chilled water air handlers. I guess that's for reduced noise in living areas and simplified / space-saving air handling. Again, efficiency isn't a huge priority. Shipboard systems need to be compact and robust rather than highly efficient.