A heat pump can also function as an air conditioner by reversing its compressor valve. American Standard produces two brands - Trane and American Standard. Trane acquired GE's HVAC unit in 1980s, then was bought by American Standard.
A heat pump can also function as an air conditioner by reversing its compressor valve.
American Standard produces two brands - Trane and American Standard. Trane acquired GE's HVAC unit in 1980s, then was bought by American Standard.
2A6H4030 means:
2 - R-22 refrigerant
A - American Standard
6 - Split Heat Pump
H - Heritage
4 - SEER 14
0 - Brazed
30 - 30K BTU (30/12 = 2.5 ton)
A heat pump can produce heat with two methods: compressor (the normal way) and coil (auxiliary or emergency). The Coefficient of Performance (COP) of coil is always 1 (e.g. it produces 1 KHW heat with 1 KWH energy). The compressor's COP varies with the difference between the indoor temperature and outdoor temperature.
The following is a figure from a DOE document for a 4-ton low temperature heat pump (LTHP) manufactured by Hallowell International :
The compressor's COP can be zero theoretically because the the temperature gap can be so big that the "heated" air is cooler than the indoor air. According to the above chart, the COP is always above 1, hence better than that of the coil in reality.
Heat pumps are not suitable for every region because some are too cold for them to handle. Southern New England is a good place for heat pump. There are only a few days each year that the inefficient auxiliary heat is needed. One can survive with bearable discomfort without using the auxiliary heat at all.
For example, at -20°C of outdoor temperature at night, in a two-floor home, the first floor temperature can be maintained above 6°C, and the second floor temperature can be maintained above 10°C.
American Standard has the best reliability: 
Heat pumps from premium brands such as American Standard should last 12 - 25 years while budget brands (Payne, Diamond Air) 12 - 16 years, standard brands (Goodman, Rheem) 15-18 years.
For Massachusetts (zone 5), one should choose American Standard Platinum 16 that has high reliability with a reasonable price (around $3K for 2.5 ton, 30K BTU) for the unit.