Temperature control of unoccupied living spaces

• US 4,215,408 A
• Filed: 12/12/1977
• Issued: 07/29/1980
• Est. Priority Date: 12/12/1977
• Status: Expired due to Term

• Current Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Games, John E., Bitterli, William W.
• Primary Examiner(s): Smith, Jerry
• Application Number:
  US05/860,026
• Time in Patent Office: 960 Days
• Field of Search: 364/505, 236/46 R, 165/12-14, 165/16, 165/22, 165/26
• US Class Current: 700/278
• CPC Class Codes: F24F 11/00 Control or safety arrangements
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/48 prior to normal operation, e.g. pre-heating or pre-cooling
• CPC Class Codes: F24F 11/52 Indication arrangements, e.g. displays
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 11/64 using pre-stored data
• CPC Class Codes: F24F 11/74 for controlling air flow rate or air velocity
• CPC Class Codes: F24F 11/76 by means responsive to temperature, e.g. bimetal springs
• CPC Class Codes: F24F 11/84 using valves
• CPC Class Codes: F24F 2003/006 with two air ducts for separately transporting treated hot and cold primary air from the central station to air treatment units located in or near the rooms
• CPC Class Codes: F24F 2011/0002 for admittance of outside air
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2110/12 of the outside air
• CPC Class Codes: F24F 2110/20 Humidity
• CPC Class Codes: F24F 2110/22 of the outside air
• CPC Class Codes: F24F 2110/32 of the outside air
• CPC Class Codes: F24F 2120/10 Occupancy
• CPC Class Codes: F24F 2221/54 Heating and cooling, simultaneously or alternatively
• CPC Class Codes: F24F 3/00 Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems room units F24F1/00
• CPC Class Codes: F24F 6/18 : by injection of steam into the air
• CPC Class Codes: G05B 15/02 : electric
• CPC Class Codes: G05D 23/1917 : using digital means
• CPC Class Codes: G05D 23/20 : with sensing elements having variation of electric or magnetic properties with change of temperature G05D23/13 takes precedence

Abstract

Apparatus is provided for controlling, during unoccupied periods, the operation of an HVAC system and perimeter heating system providing hot air and hot fluid, respectively, to a temperature controlled living space having occupied and unoccupied periods, the apparatus including an electronic processing means in combination with dedicated sensing apparatus, the apparatus providing controlled actuation of the HVAC and permieter heating system in dependence on the temperature difference between an actual space temperature signal and unoccupied space heat and cool reference temperature signals, the apparatus further providing an optimum start-up procedure including simultaneous actuation of the HVAC and perimeter heating system to accelerate the heating of the space, the HVAC discharge temperature being modulated during the start-up procedure in dependence on the temperature difference between the actual space temperature and an occupied space heat reference temperature signal, the perimeter heating system discharge temperature being preset to a start-up reference discharge temperature having a value greater than that maximum perimeter heating system discharge temperature permitted in normal operation.

Claims

1. Apparatus for controlling, in combination during unoccupied periods, the operation of an HVAC and perimeter heating system providing temperature regulation in a living space having occupied and unoccupied periods, the HVAC output including hot air from an air handler heating apparatus which modulates the discharge temperature in dependence on a space temperature error signal presented thereto at a magnitude equal to the temperature difference between an actual space temperature signal and a space heat reference temperature signal, the air handler including a fan for forcing the hot air into the space, the perimeter heating system providing hot fluid from a hot source at a determined discharge temperature, the hot fluid being presented to heaters in the space by a pump, the fan and pump each energized through connection to a voltage source, the apparatus comprising:

temperature sensor means, for providing sensed temperature signals including, an actual hot air discharge temperature signal, an actual hot fluid discharge temperature signal, and an actual space temperature signal;

electronic processing means, providing an actual time of day signal, and having means for storing signals including real time signals establishing a plurality of real time intervals, each interval representative of an associated one of the space occupied and unoccupied periods, said processing means comparing said actual time of day signal with said real time intervals for providing an unoccupied signal manifestation in response to said actual time of day signal indicating a present unoccupied period, said means for storing signals further including a perimeter heat actuating temperature signal, said processing means being responsive to said sensed temperature signals for comparing said actual space temperature signal with said perimeter heat actuating temperature signal for providing, in the presence of said unoccupied signal manifestation, a perimeter heat pump off gate signal in response to said actual space temperature signal indication of a space temperature higher than said perimeter heat actuating temperature signal; and

pump switch means, interconnected between the voltage source and the pump, and responsive to said pump off gate signal presented at a gate input thereof, said switch means providing a connection of the pump to the voltage source in the absence of said pump off gate signal, said switch means not providing the connection in the presence of said pump off gate signal.

2. The apparatus of claim 1, wherein said means for storing signals further includes an occupied space heat reference temperature signal and an unoccupied space heat reference temperature signal representative of a lower temperature value than that of said occupied space heat reference temperature signal, said processing means, in the presence of said unoccupied signal manifestation, comparing said actual space temperature signal to said unoccupied space heat reference temperature signal to provide an unoccupied space heat temperature error signal at a magnitude in dependence on the temperature difference therebetween, said processing means providing, in response to said unoccupied space temperature error signal, a hot air reference discharge temperature signal at a magnitude in dependence on said temperature difference, said processing means presenting said reference discharge signal to the HVAC heating apparatus to provide modulation of the hot air discharge temperature in dependence on the magnitude thereof.

3. The apparatus of claim 2, further comprising:

fan switch means, interconnected between the voltage source and the fan, and responsive to a fan off gate signal presented at a gate input thereof, said fan switch means providing connection of the fan to the voltage source in the absence of said fan off gate signal, said switch means not providing said connection in the presence of said fan off gate signal; and

wherein

said processing means provides said fan off gate signal in the presence of said unoccupied signal manifestation in the absence of said unoccupied space heat temperature error signal.

4. The apparatus of claim 3 wherein said perimeter heat actuating temperature signal included in said means for storing signals is representative of a higher temperature value than that of said unoccupied space heat reference temperature signal.

5. The apparatus of claim 3, wherein said means for storing signals further includes real time signals representative of a start-up time interval within each unoccupied period, said start time interval being bounded by a minimum time signal and a maximum time signal, said maximum time signal having a real time value coincident with the end of the unoccupied period, said processing means, in the presence of said unoccupied signal manifestation, comparing said actual time of day signal with said start time interval for providing a start signal manifestation in response to said actual time of day signal indicating a present time therein, said processing means, in response to said start signal manifestation, comparing said actual space temperature signal to said occupied space heat reference temperature signal to provide an occupied space temperature error signal in response to, and at a magnitude equal to, a temperature difference therebetween, said processing means, in the presence of said start signal manifestation, providing said fan off gate signal and said pump off gate signal only in the absence of said occupied space temperature error signal.

6. The apparatus of claim 5, wherein said processing means further provides, simultaneously, in the presence of said start signal manifestation, a hot air reference discharge temperature signal and a hot fluid start-up reference discharge temperature signal, said processing means providing said hot air reference discharge temperature signal at a magnitude in dependence on said occupied space temperature error signal, said processing means presenting said hot air reference discharge temperature signal to the HVAC heating apparatus to provide modulation of the hot air discharge temperature in dependence on the magnitude thereof, said processing means providing said hot fluid start-up reference discharge temperature signal at a magnitude representative of a maximum discharge temperature value greater than that provided in normal operation of the perimeter heating system hot source, said processing means presenting said start-up reference discharge temperature signal to the hot source to provide control of the hot fluid discharge temperature in dependence on the magnitude thereof.

7. The apparatus of claim 6, further comprising:

outside temperature sensor means, for providing an actual outside air temperature signal;

outside wind sensor means, for providing an actual outside air average wind speed signal; and

wherein

said processing means is responsive to said actual outside air temperature signal and said actual average wind speed signal for providing, in each start-up time interval, an optimum start-up time signal representative of a real time value which precedes that established by said maximum time signal by an incremental time period having a magnitude equal to the time required to increase said actual space temperature signal magnitude, in the presence of outside temperature and wind conditions as manifested by the magnitudes of said actual outside air temperature signal and said actual outside air average wind speed signal presented thereto, and in the presence further of hot air and hot fluid presented simultaneously thereto from the HVAC and perimeter heating systems, from that temperature value provided in a present unoccupied period through control of the hot air discharge temperature in response to said unoccupied space temperature error signal, to that temperature value provided in an occupied period by control of the hot air discharge temperature in response to said occupied space temperature error signal, said processing means further providing said start signal manifestation in response to said actual time of day signal indicative of a present time equal to that of said optimum start-up time signal.

8. The apparatus of claim 7, wherein:

said processing means further includes means for successively sampling periodically and registering in said means for storing signals, successively sampled values of said actual space temperature signal, said actual outside air temperature signal, and said actual outside air average wind speed signal;

said means for storing signals further includes a wind proportional gain signal; and

said processing means compares successively sampled values of said actual space temperature signal and said actual outside air temperature signal to provide a temperature gradient signal, in each sampling period, in response to a temperature difference therebetween, said processing means providing said optimum start-up time signal at a real time value which precedes said maximum time signal by an incremental time period having a magnitude in dependence on the product of said wind proportional gain signal, and said temperature gradient and said actual outside air average wind speed signals provided in a determined sampling period following said actual time of day signal indication of a time equal to said minimum time signal.

9. The apparatus of claim 8, wherein said processing means provides, in said determined sampling period, a squared magnitude actual outside air average wind speed signal, and said processing means further provides said optimum start-up time signal at a real time value which precedes said maximum time signal by an incremental time period having a magnitude equal to the product of said wind proportional gain signal, and said temperature gradient signal and said squared magnitude wind speed signal provided in said determined sampling period.

10. The apparatus of claim 8, further comprising:

means responsive to operator control for providing parameter signals representative of said real time intervals establishing the space occupied and unoccupied periods, said perimeter heat actuating temperature signal, said occupied space heat reference temperature signal, said unoccupied space heat reference temperature signal, said real time signals representative of said start-up time intervals, and said wind proportional gain signal, in response to selective operation thereof; and

wherein

said electronic processing means further includes means for registering said parameter signals in said means for storing signals.

11. The apparatus of claim 2, further comprising:

means responsive to operator control for providing parameter signals representative of said real time intervals establishing the space occupied and unoccupied periods, said perimeter heat actuating temperature signal, said occupied space heat reference temperature signal, and said unoccupied space heat reference temperature signal, in response to selective operation thereof; and

wherein

said electronic processing means further includes means for registering said parameter signals in said means for storing signals.

12. The apparatus of claim 1, wherein:

said sensed temperature signals provided by said temperature sensor means further includes an actual outside air temperature signal;

said means for storing signals further includes unoccupied proportional gain signals, each at a magnitude associated with a different value of said actual outside air temperature signal, said gain signals having magnitudes extending from a maximum value associated with a minimum outside air temperature signal magnitude, to a minimum value associated with a maximum outside air temperature signal magnitude; and

said processing means further includes means for successively sampling periodically and registering in said means for storing signals, successively sampled values of said sensed signals including said actual outside air temperature signal, said processing means providing in each sampling period, in the presence of said unoccupied signal manifestation in the absence of said pump off gate signal, an unoccupied hot fluid reference discharge temperature signal at a magnitude in dependence on the product of said actual outside air temperature signal related to said sampling period and the unoccupied proportional gain signal associated therewith, said processing means presenting said unoccupied hot fluid reference discharge temperature signal to the hot source to provide modulation of the hot fluid discharge temperature in dependence on the magnitude thereof.

13. The apparatus of claim 12, further comprising:

means responsive to operator control for providing parameter signals representative of said real time intervals establishing the space occupied and unoccupied periods, said perimeter heat actuating temperature signal, and said unoccupied proportional gain signals, in response to selective operation thereof; and

wherein

said electronic processing means further includes means for registering said parameter signals in said means for storing signals.

14. Apparatus for controlling, during unoccupied periods, the operation of an HVAC providing temperature conditioned air to a living space having occupied and unoccupied periods, the HVAC including heating and cooling apparatus for conditioning mixed air, including outside air and return air from the space, presented in heat exchange relationship therewith by a fan from a mixed air chamber, the fan being energized by connection to a voltage source, the heating and cooling apparatus providing heat and cold air at a discharge temperature in dependence on hot and cold space temperature error signals presented thereto at a magnitude equal to the temperature difference between an actual space temperature and corresponding space heat and cool reference temperatures, the HVAC presenting mixed air to the space in the absence of space temperature error signals, the mixed air chamber including outside air and return air dampers for providing the mixed air through position modulation of the dampers in response to a mixed air space temperature error signal presented thereto at a magnitude equal to the temperature difference between the actual space temperature and a space mixed air reference temperature, the apparatus comprising:

HVAC temperature sensor means for providing an actual hot air discharge temperature signal, an actual cold air discharge temperature signal, and an actual mixed air temperature signal;

space temperature sensor means for providing an actual space temperature signal;

outside temperature sensor means for providing an actual outside air temperature signal;

electronic processing means, providing an actual time of day signal, and having means for storing signals including real time signals establishing a plurality of real time intervals, each interval representative of an associated one of the space occupied and unoccupied periods , said processing means comparing said actual time of day signal with said real time intervals for providing an unocupied signal manifestation in response to said actual time of day signal indicating a present unoccupied period, said means for storing signals further including occupid space heat and cool reference temperature signals, and unoccupied space heat and cool reference temperature signals at a lower and higher temperature value, respectively, than the corresponding occupied reference signals, said processing means being responsive to said sensor means for providing, in the presence of said unoccupied signal manisfestation, a comparison of said actual space temperature signal to said unoccupied space heat and cool reference temperature signals to provide unoccupied space heat and cool temperature error signals, respectively, in response to a temperature difference therebetween, said processing means providing hot air and cold air reference discharge temperature signals in response to the presence of a related one of said unoccupied space heat and cool temperature error signals, each at a magnitude in dependence on the associated one of said unococupied space heat and cool temperature error signals, said processing means presenting said reference discharge temperature signals to the heating and cooling apparatus to provide modulation of the respective discharge temperatures in dependence on the magnitude thereof, said processing means further providing, in the presence of said unoccupied signal manifestation in the absence of both of said unoccupied space heat and cool temperature error signals, a fan turn-off gate signal; and

gated switch means, interconnected between the voltage source and the fan, and responsive to said fan turn-off gate signal presented at a gate input thereof, said switch means providing connection of the fan to the voltage source in the absence of said turn-off gate signal, said switch means not providing connection of the fan to the voltage source in the presence of said turn-off gate signal.

15. The apparatus of claim 14, wherein:

said means for storing signals further includes a space mixed air reference temperature signal representative of a temperature value within a range of temperatures between said unoccupied space heat reference temperature signal and said unoccupied space cool reference temperature signal, said means for storing signals further including real time signals representative of a precool time interval in each unoccupied period; and

wherein

said processing means compares said actual time of day signal with said real time signals representative of said precool interval for providing a precool signal manifestation in response to said actual time of day signal indicating a present precool time interval, said processing means, in the presence of said precool signal manifestation, comparing said actual space temperature signal to said space mixed air reference temperature signal to provide a mixed air space temperature error signal at a magnitude in dependence on a temperature difference therebetween, said processing means, in the presence of said precool signal manifestation, providing said fan turn-off gate signal only in response to the absence of said mixed air space temperature error signal, said processing means presenting said mixed air temperature signal to the HVAC mixed air chamber to provide position modulation of the outside air and return air dampers in response to said temperature difference.

16. The apparatus of claim 15, further comprising:

means responsive to operator control for providing parameter signals representative of said real time signals indicative of the space occupied and unoccupied periods, said real time signals indicative of said precool time interval, said occupied space heat and cool reference temperature signal, said unoccupied space heat and cool temperature reference signals, and said space mixed air reference temperature signal, in response to selective operation thereof; and

wherein

said electronic processing means further includes means for registering said parameter signals in said means for storing signals.