Control system to delay the operation of a refrigeration heat pump apparatus after the operation of a furnace is terminated

• US 4,703,795 A
• Filed: 08/20/1984
• Issued: 11/03/1987
• Est. Priority Date: 08/20/1984
• Status: Expired due to Fees

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Beckey, Thomas J.
• Primary Examiner(s): Cline, William R.
• Assistant Examiner(s): Ford, John K.
• Application Number:
  US06/642,601
• Time in Patent Office: 1,170 Days
• Field of Search: 236/68 B, 236/1 ER, 236/1 EA, 165/27, 165/26, 165/29
• US Class Current: 165/240
• CPC Class Codes: F24D 19/1039 the system uses a heat pump
• CPC Class Codes: G05D 23/1912 whose output amplitude can take more than two discrete values
• CPC Class Codes: G05D 23/275 with sensing element expanding, contracting, or fusing in response to changes of temperature

Abstract

A multistage space thermostat control system for controlling a refrigeration heat pump and a furnace controls the heat pump from a first stage of a space thermostat and a furnace from a second stage with anticipation circuit means associated with said thermostat control system which is changed in effectiveness depending upon the operation to reduce temperature swings in the space.

Claims

1. An improvement in a control system having a multistage space thermostat for controlling the operation of a refrigeration heat pump and a furnace, furnishing heated air through a common duct to a space, to prevent operation of the heat pump after operation of the furnace until sufficiently low air temperature from the furnace exists wherein upon a drop in the space temperature below a first predetermined temperature a first stage of said thermostat energizes the heat pump and upon a further drop in space temperature below a second predetermined temperature a second stage of said thermostat energizes the furnace, the thermostat having anticipation circuit means, the improvement comprising,

means actuated upon energization of said furnace by said second stage when a make temperature is reached for disconnecting said heat pump from said first stage thermostat,

further means actuated by said second stage for energizing said furnace by said first stage until a break temperature is reached whereby said furnace remains energized until said first stage is satisfied, and

means for increasing the output of the anticipation circuit means controlled by said first stage to reduce said break temperature of said first stage during the period between when said second stage turns on said furnace and said first stage turns off said furnace to reduce swings in space temperature due to a larger differential in the thermostat operation.

2. In a control system for a refrigeration heat pump and an auxiliary heat high temperature source wherein heated medium is supplied to a space by a common means and it is desired not to operate the heat pump until the temperature of the medium by the high temperature source is reduced to predetermined level,

two stage space thermostat means, a first of said two stages calling for heat at a first predetermined space temperature and a second of said two stages calling for heat at a second lower predetermined space temperature,

first actuator means adapted to control the operation of the heat pump,

first circuit means connecting said first stage of said two stage thermostat to said first actuator means to effect operation of the heat pump upon a call for heating by said first stage when the space temperature drops below said first predetermined temperature,

second actuator means adapted to control the operation of the high temperature source,

second circuit means connecting said second stage of said two stage thermostat to said second actuator means to effect operation of the high temperature source upon a call for heating by said second stage when the space temperature drops below said second predetermined temperature,

anticipation circuit means connected to said thermostat means, said anticipation circuit means having a variable anticipation,

first means associated with said second actuator means when energized for opening said first circuit means to deenergize said first actuator means and the heat pump,

second means associated with said second actuator means when energized for connecting said second actuator means to said first stage to maintain the high temperature source operating until said first stage is satisfied, and

third means associated with said second actuator means connected to said anticipation circuit means to increase its anticipation effect on said first stage when said high temperature heat source is operated to reduce swings in the space temperature due to the larger differential between the turning on of the high temperature source and the turning off of the high temperature source.

3. The invention of claim 2, wherein

said two stage space thermostat means has a first temperature responsive switch means for controlling said first actuator means and a second temperture responsive switch means for controlling said second actuator means, and said anticipation circuit means comprises

a first anticipation heater associated with and controlled by said first temperature responsive switch means and a second anticipation heater associated with and controlled by said second temperature responsive switch means, and

circuit means associated with said second actuator means when energizing the high temperature source for connecting said second anticipation heater to also be controlled by said first temperature responsive switch means to increase the amount of heat to said first temperature responsive switch means while it is maintaining the energization of the high temperature source.

4. The invention of claim 2 wherein,

said first stage of said thermostat has a temperature responsive switch means operating with a predetermined temperature differential between a closed and open circuit condition,

said second stage of said thermostat has a temperature responsive switch means operating with a predetermined temperature differential between a closed and open circuit condition, and

said second circuit means increasing the capacity of said anticipation means when the high temperature heating apparatus is operating between the closed position of stage two and the open position of stage one.

5. In a control system for a refrigeration heating apparatus and a high temperature heating apparatus wherein simultaneous operation of said apparatuses is not desired as the high temperature heating apparatus adversely affects the refrigeration heating apparatus and a delay in the operation of said refrigeration apparatus is desired after the high temperature apparatus operation is terminated, comprising:

two stage space thermostat means having a first stage adapted to operate the refrigeration heating apparatus and a second stage adapted to operate the high temperature heating apparatus,

first anticipation circuit means connected to said first stage of said thermostat means to be operated when said first stage calls for heat,

second anticipation circuit means connected to said second stage of said thermostat means to be operated when said second stage calls for heat,

circuit means connected to said second stage when operating said high temperature heating apparatus for rendering said refrigeration heating apparatus inoperative, and

second circuit means connected to said second stage for connecting said high temperature heating apparatus to said first stage and connecting said first and second anticipation circuit means to said first stage to be operated together to affect the operation of said first stage when said first stage calls for heat to reduce space temperature swings in the space.