摘要 |
<p>A multistage timer control setback thermostat control system maintaining a normal temperature in a space and during selected time periods a reduced temperature wherein a first stage is a refrigeration heat pump, the operation of which is affected by outdoor temperature, and a second stage is an auxiliary electrical heating source. An outdoor temperature responsive means is connected in the control system to maintain the heat pump energized during the space temperature setback period if the outdoor temperature is below some predetermined value. Additionally, the indoor thermostat has a high limit temperature responsive means for terminating the operation of the heat pump should the space temperature exceed some predetermined value during the space temperature setback period.</p> |