Posted by Harold Kestenholz - Hydronic Network on January 01, 2000 at 20:30:47:
In Reply to: Geothermal heat pump compatible w/ hot water heat? posted by Marcia on January 01, 2000 at 17:33:47:
1960's homes were insulated to a value of half the standard of insulation today. Geothermal heat pump compressor discharge water does not reach the 180F water temperature designs of hot water heating systems. A geothermal heat pump system may reach 140F water temperatures or less. If you upgrade your insulation to modern standards, thereby cutting the heat loss in half, the same baseboard will then supply the heat.
Geothermal heat pumps are capable of making the electricity used produce four times the heat that resistance heat would. This would make your electric heating bill equal to that of gas or oil heat for the modest investment of about $15,000 for the geothermal heating installation. So if a loan to amortise this investment is included in a 20 year mortgage, you will wind up with an additional monthly bill of about $84 beyond your existing cost of oil or gas for the privilege of having a techie kind of heat that relatively few can service or maintain. Cutting your heat loss in half should pay for the amortised cost.
The average life of a compressor is 10 years, so you can expext a new contactor every three years and a new compressor for about $2000 every ten years (perhaps a newer system then.) A cover-all service contract should only cost an additional charge of about $350 per year. But why continue using pedestrian tried-and-true heating systems that have worked for over 100 years when you can have a unique and rare showcase system totally dependent upon the price of electricity that can dazzle the neighbors?