Head Pump Space Heating
Courtesy of Rheem
The Rheem RP 20 space heating heat pump has a SEER (Seasonal Energy Efficiency Ratio) of 20 and a HSPF (Heating Season Performance Factor) of 13. In both case the larger the value the better. It's available in 2,3,4, and 5 ton sizes. 12,000 BTU/hr is one ton.
Courtesy of Lennox
The Lennox XP20 has a SEER of 20 and HSPF of 9.6 to 10.
The heat pump units pictured above are installed outside, next to the house and on a concrete slab. Refrigerant lines are brought inside to the furnace room and connected to coils or tubing in the air handler. In some cases the old natural gas furnace can be used to blow air throughout the house, but now heated with the heat pump outside. The efficiency of the space heating heat pump goes down as the outside temperature drops. Either electric coils or natural gas can back up the heat pump on very cold winter nights. Compared to a natural gas furnace, the operating cost of heat pump space heating is about double. Bruce Hodge estimated on his web site that purchase and installation of the heat pump space heating heating system to be about $8,500.One key advantage of going to a heat pump for space heating is that it can be used for cooling the home in the Summer months. In most cases, air conditioning is not needed in Palo Alto with our cool nights, but that could change with global warming.