Water-to-air heat pumps using ground source closed-loop water or anti-freeze as the heat source and sink are offered by a number of manufacturers. Because winter ground loop temperatures can drop below freezing, these systems require extended rating designs.

Units are available in a number of configurations. Air flow is usually in the 400 cfm per ton range.

Configurations and nominal cooling ranges include:

Vertical upflow air discharge from ¾ to 10 tons

Vertical counterflow air discharge from 1 to 6 tons

Horizontal ceiling mounted from ½ to 10 tons

Dual compressor units in the above 3 categories

Split systems (compressor/water heat exchanger and air handling sections) from 1¼ to 5 tons

Large commercial vertical upflow air discharge from 10 to 30 tons.

Other specialty extended rating designs available include:

Two speed units, horizontal and vertical from 2½ to 6 tons

Floor mounted console units from ½ to 1½ ton sizes

Hi-rise vertical units, pre-piped and wired, built-in or flush mounted from ½ to 3 tons

Large commercial vertical variable air volume units, Rooftop packages from 5 to 25 tons

Schoolroom Unit Ventilator units from 2 to 4 tons.

Manufacturers offer a wide range of optional accessory items including: hot water generators, system controls, supplemental electric heat packages, dehumidification options, cupro-nickel water-to-refrigerant heat exchangers, hose kits, cabinet paint finishes, improved filters, sound attenuation packages, flow centers (loop pump modules).