04918933 is referenced by 11 patents and cites 6 patents.

This invention relates to a method of supplying desired quantities of heat, generated from selected inexpensive fuel burns in the firebox of a boiler, to an electric heat pump's refrigerant, while operating in its heating cycle. This supply of heat can be of sufficient quantities to satisfy the total ouput of the heat pump, minimizing its use of electricity, thereby creating a substantial savings, as the cost of the heat generated by the inexpensive fuel used by the boiler is much less than the cost of electricity.

Title
Add-on refrigerant boiler for electric heat pump
Application Number
7/270772
Publication Number
4918933
Application Date
November 14, 1988
Publication Date
April 24, 1990
Inventor
David F Dyer
P.O. Box 2255, Auburn, 36831
AL, US
IPC
F25B 7/00
View Original Source