05259445 is referenced by 116 patents and cites 18 patents.

A programmable thermostat is provided for the selective operation either of a fossil fuel furnace or a heat pump. The thermostat is programmed to operate the fossil fuel furnace when the outside temperature is below a preselected temperature range, and to operate the heat pump when the outside temperature is above the preselected temperature range. Within the preselected temperature range, the fossil fuel furnace may be operated during certain time periods and the heat pump may be operated during other time periods.

Title
Control for dual heating system including a heat pump and furnace
Application Number
7/912506
Publication Number
5259445
Application Date
July 13, 1992
Publication Date
November 9, 1993
Inventor
William S Gianino
Lake Orion
MI, US
Lawrence A Kasik
Livonia
MI, US
Robert G Pratt
Farmington Hills
MI, US
Agent
Barnes Kisselle Raisch Choate Whittemore & Eulbert
Assignee
The Detroit Edison Company
MI, US
IPC
F25B 13/00
F25B 29/00
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