Zone demand controlled dual air conditioning system and controller therefor

• US 6,792,766 B2
• Filed: 10/04/2002
• Issued: 09/21/2004
• Est. Priority Date: 10/04/2002
• Status: Active Grant

• Current Assignee: Cascade Manufacturing, L.P.
• Original Assignee: Cascade Manufacturing, L.P.
• Inventors: Osborne, David, Chester, Brian, Scoggins, Gary R.
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US10/264,645
• Publication Number:
  US 20040065095A1
• Time in Patent Office: 718 Days
• Field of Search: 621/59, 621/62, 622/01, 622/386, 622/387, 621/75, 622/591, 621/77, 621/78, 621/79, 621/80, 165/217, 165/220, 236/1.B
• US Class Current: 62/159
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• 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: F25B 39/02 Evaporators
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A thermal zone demand controlled air conditioning fan coil unit using dual cascade arranged heat pumps, chilled water, or a combination of chilled water and hot water, with or without back up electric resistance heat strips, and having an air circulation system for circulating air to and from a plurality of thermal zones and including a conditioned air chamber having first and second heat exchange refrigerant coils or direct or reversed cycle water coils being connected in refrigerant circulating relation respectively with the heat pumps, chilled water coil. A plurality of thermal zone blowers conduct conditioned air from the conditioned air chamber to respective thermal zones of a building space. Electronic controller circuitry of the system is coupled for thermal demand control of the heat pumps and the thermal zone blowers for operation of the first heat pump during average thermal load and for operation of both heat pumps during greater thermal load. For chilled or hot water systems, the controller controls operation of thermal zone blowers and motorized valves which control the flow of water to and from the water coils. The electronic controller circuitry further provides thermostat control circuitry having set point change capability at any of the thermal zone thermostats and periodically reverses heat pump operation to compensate for uneven wear.

Claims

1. A thermal zone demand controlled air conditioning system for heating and cooling the air of a building space having a plurality of thermal zones, comprising:

an air circulation system for circulating air to and from said thermal zones and having a conditioned air chamber and a plurality of conditioned air supply conduits each being in communication with said conditioned air chamber and being in conditioned air supplying relation with a respective one of said thermal zones of the building space;

a plurality of sources of heating and cooling being located externally of said building space and having first and second heat exchangers located in series within said air circulation system and being connected in thermal exchange circulating relation respectively with said plurality of sources of heating and cooling and selectively heating and cooling air flowing to said conditioned air chamber;

a plurality of thermal zone blowers each having a multi-speed electric blower motor and being in communication with said conditioned air chamber and with respective conditioned air supply conduits and being connected in said air circulation system and conducting conditioned air from said conditioned air chamber through respective air supply conduits to respective thermal zones of said building space;

a dc control power supply circuit and an ac power supply circuit;

a plurality of thermal zone blower circuits each being operationally connected to respective multi-speed electric motors of said thermal zone blowers for control by said dc control power supply circuit, each of said zone blower circuits having multi-speed electric motor control devices controlling blower motor operation and speed by said ac power supply circuit;

a plurality of thermostats each being located within a respective thermal zone of said building space and being electronically connected with said dc control power supply of said electronic controller circuitry and having respective low and high temperature signal conductors being energized at respective low and high predetermined temperatures; and

electronic controller circuitry being coupled for sensed thermal demand control of said plurality of sources of heating and cooling and for control of said plurality of multi-speed electric blower motors of said thermal zone blowers for operation of one of said plurality of sources of heating and cooling to accommodate a predetermined range of thermal load and for operation of at least one other of said plurality of sources of heating and cooling to accommodate a range of thermal load in excess of said predetermined range of thermal load and for selective operation of said plurality of thermal zone blowers responsive to sensed conditions of thermal load of said plurality of thermal zones.

2. The thermal zone demand controlled air conditioning system of claim 1, comprising:

said plurality of sources of heating and cooling being first and second cascade arranged heat pumps located externally of said building space and having a coil unit having first and second refrigerant coils located in series within said air circulation system and being connected in refrigerant circulating relation respectively with said first and second heat pumps and selectively heating and cooling air flowing to said conditioned air chamber.

3. The thermal zone demand controlled air conditioning system of claim 2, wherein said coil unit comprises:

a coil housing being connected in said air circulation system for receiving return air from said plurality of thermal zones of said building and directing circulating air to said conditioned air chamber;

said first and second refrigerant coils being located in series within said coil housing; and

said first and second refrigerant coils each-having refrigerant supply and return lines being in communication therewith.

4. The thermal zone demand controlled air conditioning system of claim 1, comprising:

a coil unit having a coil housing being connected in said air circulation system and receiving return air from said plurality of thermal zones of said building;

a plurality of water coils being located in series within said coil housing; and

said plurality of thermal sources being a plurality of water chiller units and water heating units and each having water supply and return lines being in communication with said plurality of water coils.

5. The thermal zone demand controlled air conditioning system of claim 1, comprising:

said plurality of sources of heating and cooling each being a chilled water system for providing cooling to circulating air through heat exchanger coil and each having an air side electric resistance heating element selectively heating air flowing to said conditioned air chamber.

6. The thermal zone demand controlled air conditioning system of claim 1, comprising:

a chilled water system having a fin and tube heat exchanger coil of multiple row in depth providing cooling of water;

a hot water system providing heating of water through a fin and tube heat exchanger of multiple row in depth; and

a thermal demand responsive electronic system controller for controlling selective activation of said chilled water system and said hot water system for heating and cooling the air of said plurality of thermal zones of said building space responsive to individually sensed thermal demand of said plurality of thermal zones.

7. The thermal zone demand controlled air conditioning system of claim 1, comprising:

said plurality of sources of heating and cooling having external to the building space a plurality of packaged chillers each having a chilled water coil located in said air circulation system and cooling and circulating water in a closed water circulation loop to and from the chilled water coil and said plurality of packaged chillers each being independently operated according to thermal demand of said plurality of thermal zones and cooling air flowing to said conditioned air chamber.

8. The thermal zone demand controlled air conditioning system of claim 1, comprising:

said plurality of sources of heating and cooling being a packaged water chiller device and a packaged water heater device both being located external to the building space;

said packaged water chiller device having a closed chilled water circulation loop defining a two pipe circuit and having a chilled water coil being located in said air circulation system and selectively cooling and circulating water in said closed water circulation loop to and from said chilled water coil and cooling air flowing through said chilled water coil to said conditioned air chamber;

said packaged water heating device having a closed heated water circulation loop defining a two pipe circuit and having a heated water coil being located in said air circulation system and in series with said chilled water coil and selectively heating and circulating water to and from the heated water coil and heating air flowing through said heated water coil to said conditioned air chamber.

9. The thermal zone demand controlled air conditioning system of claim 1, comprising:

said plurality of sources of heating and cooling being external to the building space both a packaged water chiller device and a packaged water heating device;

a closed two pipe water circulating loop connected with said water coil and circulating the water in a closed water circulation loop to and from the water coil; and

at least one connection device selectively connecting said two pipe water circulating loop with said packaged water heating device for circulating heated water in a closed loop to and from the water coil and heating air flowing to said conditioned chamber and selectively connecting said two pipe water circulating loop with said packaged water chiller device for circulating chilled water in a closed loop to and from the water coil and heating air flowing to said conditioned chamber for cooling air flowing through said conditioned air chamber.

10. The thermal zone demand controlled air conditioning system of claim 1, comprising:

said water coils being at least one chilled water coil and at least one hot water coil;

said plurality of sources of heating and cooling being external to the building space both a packaged chiller device selectively cooling water and a packaged water heating device selectively heating water;

a first closed chilled water circulating loop connected with said chilled water coil and circulating the water in said water circulation loop to and from the chilled water coil and cooling air flowing to said conditioned chamber; and

a second closed loop hot water circulating loop connected with said packaged water heating device and circulating heated water to and from the hot water coil and heating air flowing to said conditioned chamber, where the water circulates in a two pipe circuit.

11. The thermal zone demand controlled air conditioning system of claim 10, comprising:

said chilled water flowing in a separate and distinct two pipe chilled water circuit and said hot water flowing in a separate and distinct two pipe circuit.

12. The thermal zone demand controlled air conditioning system of claim 1, wherein said air circulation system comprises:

a coil unit being located within said air circulation system;

first and second heat exchangers being located within said coil unit and having heat exchanging connection with said plurality of sources of heating and cooling;

a conditioned air housing defining a conditioned air chamber in communication with said coil unit and receiving conditioned air flowing through said first and second heat exchangers;

said plurality of thermal zone blowers being mounted to said conditioned air housing and having conditioned air supplying communication with said plurality of conditioned air supply conduits; and

said electronic controller circuitry selectively operating said plurality of thermal zone blowers at blower speeds determined by the individual thermal demand of said plurality of thermal zones.

13. The thermal zone demand controlled air conditioning system of claim 12, comprising:

electric motors driving each of said plurality of thermal zone blowers and being multi tapped motors with multiple motor speeds.

14. The thermal zone demand controlled air conditioning system of claim 12, comprising:

electric motors driving each of said plurality of thermal zone blowers and being variable frequency drive motors with multiple motor speeds.

15. The thermal zone demand controlled air conditioning system of claim 1, comprising:

said environmental control circuitry being digital electronic control circuitry and being connecting in controlling relation with said plurality of sources of heating and cooling and with said plurality of thermal zone blowers for selective operation thereof responsive to thermal load of said plurality of thermal zones.

16. The thermal zone demand controlled air conditioning system of claim 1, comprising:

said environmental control circuitry being pneumatic control circuitry and being connecting in controlling relation with said plurality of sources of heating and cooling and with said plurality of thermal zone blowers for selective operation thereof responsive to thermal load of said plurality of thermal zones.

17. The thermal zone demand controlled air conditioning system of claim 1, wherein said air circulation system comprises:

a return air housing defining an air return chamber and a conditioned air chamber;

said first and second heat exchangers being fluid conducting heat exchange coils collectively defining an air flow and conditioning partition through which return air flows from said air return chamber to said conditioned air chamber and accomplishing heat transfer to or from either of said heat exchange coils;

a return air plenum for receiving return air from said thermal zones;

a return air blower being connected to said return air plenum and forcing return air from said return air plenum into said return air chamber and through said first and second heat exchange coils; and

said plurality of thermal zone blowers being connected to said housing and each being in communication with said conditioned air housing and having respective electric motors being independently operable by said electronic control circuitry and independently supplying conditioned air from said conditioned air chamber through respective air supply conduits to respective thermal zones.

18. The thermal zone demand controlled air conditioning system of claim 17, wherein:

said heat exchange coils being refrigerant coils; and

said plurality of sources of heating and cooling being first and second heat pumps;

said electronic controller circuitry having an environmental control circuit and a plurality of electronic thermostats each being located within one of said thermal zones and each being connected with said environmental control circuit and a microprocessor receiving temperature responsive signals from said plurality of electronic thermostats and controlling operation and operating speed of said plurality of thermal zone blowers.

19. The thermal zone demand controlled air conditioning system of claim 17, wherein:

said heat exchange coils being water coils arranged in series within said air return chamber; and

said plurality of sources of heating and cooling being at least one water chiller device having a chilled water coil being located within said return air chamber and at least one water heater device having a heated water coil being located within said return air chamber and being located in series with said chilled water coil;

a water circulation system having at least one pump and at least one reversing valve selectively controlling water flow in said water circulation system and through said chilled and heated water coils; and

said electronic control circuitry having an environmental control circuit and having a plurality of electronic thermostats each being located within one of said thermal zones and each being connected with said environmental control circuit, said environmental control circuit having a microprocessor receiving temperature responsive signals from said plurality of electronic thermostats and controlling operation and operating speed of said plurality of thermal zone blowers and said return air blower, controlling energization of said at least one pump and selectively controlling actuation of said at least one reversing valve for selective circulation of chilled and heated water through said chilled and heated water coils.

20. The thermal zone demand controlled air conditioning system of claim 1, wherein said air circulation system comprises:

a housing defining an air return chamber and a conditioned air chamber;

said at least one coil being a first and second chilled water coils being arranged in series and collectively defining an air flow and conditioning partition between said air return chamber and said conditioned air chamber through which return air flows from said air return chamber to said conditioned air chamber through said chilled water coils and accomplishing heat transfer from chilled water circulating through said first and second chilled water coils;

first and second chilled water circuits being connected respectively with said first and second chilled water coils and having first and second pumps each independently circulating chilled water through said first and second chilled water circuits and each having a reversing valve;

a return air plenum receiving return air from said thermal zones;

a return air blower being connected to said return air plenum and forcing return air from said return air plenum into said return air chamber and through said first and second heat exchange coils; and

said plurality of thermal zone blowers being connected to said housing in communication with said conditioned air chamber and having respective electric motors being independently controlled as to operation by said electronic control circuitry and being arranged for independent supply of conditioned air from said conditioned air chamber through respective air supply conduits to respective thermal zones.

21. The thermal zone demand controlled air conditioning system of claim 1, wherein:

said plurality of thermal zone blowers each having inlet guide vanes being controlled by direct digital control signals.

22. The thermal zone demand controlled air conditioning system of claim 1, wherein:

said plurality of thermal zone blowers each having inlet guide vanes being controlled by pneumatic control signals.

23. The thermal zone demand controlled air conditioning system of claim 1, wherein:

said plurality of thermostats each having a mode selector switch having a “

cool”

position for air conditioning by said sources of heating and cooling and a “

heat”

position for heating by said sources of heating and cooling and an “

off”

position for deenergizing said sources of heating and cooling; and

a “

cool”

selector circuit and a “

heat”

selector circuit being provided in each of said plurality of thermostats, said “

cool” and

“

heat”

selector circuits each having circuit contacts being selectively closed by said mode selector switch;

said first and second sources of heating and cooling being first and second heat pumps each having an electric resistance heat strip element, energization of said “

cool”

selector circuit designating first and second stages of cooling by selective operation of said first and second heat pumps and energization of said “

heat”

selector circuit designating first, second and third stages of heating via said first and second heat pumps and said electric resistance heat strip elements of said first and second heat pumps.

24. The thermal zone demand controlled air conditioning system of claim 1, wherein:

said plurality of thermostats each having a mode selector switch having a “

cool”

position for air conditioning by said sources of heating and cooling and a “

heat”

position for heating by said sources of heating and cooling and an “

off”

position for deenergizing said sources of heating and cooling; and

a “

cool”

selector circuit and a “

heat”

selector circuit being provided in each of said plurality of thermostats, said “

cool” and

“

heat”

selector circuits each having circuit contacts being selectively closed by said mode selector switch;

said plurality of sources of heating and cooling comprise water chillers, water heaters, a plurality of water control valves and having a plurality of water coils being located in series within said conditioned air chamber;

said electronic controller circuitry selectively positioning said plurality of water control valves to control the volume of water flow through said water coils and thus properly regulate the temperature to the water being circulated through said plurality of water coils within said conditioned air chamber; and

energization of said “

cool”

selector circuit designating first and second stages of cooling by selective operation of said water chillers and energization of said “

heat”

selector circuit designating first and second and third stages of heating by selective operation of said water chillers and said water heater.

25. The thermal zone demand controlled air conditioning system of claim 5, comprising:

thermostats being located within respective thermal zones of said building space and each having a mode selector switch having “

heat”

, “

cool” and

“

off”

modes;

said plurality of chilled water systems each having a water pump motor and each being located external to the building space and each pump motor having a power supply and a power control relay for selectively connecting said power supply with the pump motor thereof and operating the selected pump motor;

a plurality of operational relays for said sources of heating and cooling each having activation coils and having equipment power control conductors connected to said power control relays of respective equipment for operation thereof and further having relay switched contacts for said power control conductors; and

said activation coils of said operational relays of said sources of heating and cooling being selectively energized responsive to temperature control signals of either of said plurality of thermostats and selective positioning of said mode selector switches of said thermostats.

26. The thermal zone demand controlled air conditioning system of claim 25, wherein said electronic controller circuitry further comprises:

a plurality of control relays each having an operational coil connected for selective energization by said dc power supply and having power circuits being connected with said ac power supply and power control connections being selectively energized by said ac power supply for control power supply to respective sources of heating and cooling upon dc current energization of the operational coil thereof; and

a reversing relay having first and second dc power supply circuits being selectively energized by completion of said “

cool”

selector circuit and said “

heat”

selector circuit, said first dc power supply circuit being connected to the coil of the power control relay for a first source of heating and cooling and said second dc power supply circuit being connected to the coil of the power control relay for a second source of heating and cooling for selection of either of said first and second sources of heating and cooling as the primary or secondary source of heating and cooling responsive to selective completion of said “

cool” and

“

heat”

selector modes of said thermostats.

27. The thermal zone demand controlled air conditioning system of claim 1, further comprising:

a plurality of thermostats being located within respective thermal zones, each of said thermostats comprising;

a thermostat power supply conductor being connected with said controller power supply;

a temperature sensor having an electric power base connected to said thermostat power supply conductor and having electronic logic reflecting blower speed and having blower speed electrical connections responsive to the sensing of predetermined low and high temperatures; and

a microprocessor having low temperature and a high temperature settings selectively energize said controller power supply responsive to temperature in the respective thermal zone sensed by said temperature sensor of said thermostat for selectively controlling energization of said blower speed of said thermal zone blower by said controller power supply.

34. The thermal zone demand controlled air conditioning system of claim 27, wherein said plurality of thermostats comprise:

a solid state thermostat device having a thermostat microprocessor managing the input data from the temperature sensor;

based on the temperature sensed said thermostat microprocessor energizing the blower motors at low speed when the measured temperature is one degree away from the set point temperature and energizes a first of said heat pumps;

based on the temperature sensed said thermostat microprocessor energizing the blower motors at a higher speed when the measured temperature is two degrees away from the set point, the microprocessor energize energizing the blower motor at a higher speed as needed to condition the air within said conditioned chamber for the heating or cooling that is needed; and

a low temperature electrical relay and a high temperature electrical relay being selectively energized by said controller power supply responsive to temperature in the respective thermal zone sensed by said temperature sensor of said thermostat for selectively controlling energization of said low speed and high speed coils of said thermal zone blower by said controller power supply.

28. A thermal zone demand controlled air conditioning system for building spaces having a plurality of thermal zones therein, comprising:

a plurality of sources of heating and cooling being located externally of the building space;

an electronic environmental control system having a microprocessor with firmware controlling relays and settings for blower motor operation at “

cool”

, “

heat” and

“

off”

modes of operation;

a plurality of thermostats each being located within a respective one of said plurality of thermal zones and sensing the temperature of conditioned air therein, said plurality of thermostats each having firmware associated with the electronic environmental control system making the relays and settings at the thermostats congruent such that the set thermal zone temperature is maintained based on thermostat mode selection and set point;

a conditioned air supply and return assembly having a conditioned air chamber, an air return plenum and a plurality of air supply conduits conducting conditioned air from said conditioned air chamber to respective thermal zones;

a plurality of thermal zone air supply blowers with motors each being situate for moving conditioned air from said conditioned air chamber through respective air supply conduits to respective thermal zones;

an internal heat exchange coil for each of said plurality of sources of heating and cooling being in series with within said conditioned air chamber upstream of said air supply conduits and blowers; and

an air return blower being located within said conditioned air chamber and forcing air from said air return plenum into said conditioned air chamber through said internal coils.

29. The thermal zone demand controlled air conditioning system and environmental control system of claim 28, wherein:

said plurality of sources of heating and cooling heat pumps;

electronic heat pump and blower control circuitry being selectively conditioned to select one of said heat pumps as the primary heat pump for operation to accommodate a predetermined thermal load and to select the other of said heat pumps as the secondary heat pump for operation simultaneously with said primary heat pump to accommodate thermal load in excess of said predetermined thermal load, said electronic heat pump and blower control circuitry also being selectively conditioned for reversing said primary and secondary selection of said pair of heat pumps; and

said electronic heat pump and blower control circuitry further having a plurality of zone control circuits each being electronically coupled with one of said plurality of thermostats for thermal zone and thermal load controlled zone blower and heat pump control signals.

30. The thermal zone demand controlled air conditioning system and system controller of claim 28, wherein said plurality of thermostats each comprise:

a mode selection through the configuration settings can be set in a “

cool”

state for air conditioning by said sources of heating and cooling, and a “

heat”

mode for heating by said sources of heating and cooling, a “

fan only”

position which will allow fans to run and overrides and prevents the sources of heating and cooling from operating and an “

off”

position deenergizing said sources of heating and cooling.

31. The thermal zone demand controlled air conditioning system and electronic system controller of claim 28, wherein:

said plurality of sources of heating and cooling being heat pumps, firmware logic in said microprocessor selectively alternating selection of which heat pump is electronically designated primary and secondary to achieve balance of the run time of said heat pumps.

32. The thermal zone demand controlled air conditioning system and electronic system controller of claim 29, comprising:

said plurality of heat pumps each having a compressor motor;

said plurality of heat pumps each having an ac operating power supply and having a dc circuit having a microprocessor and with logic in the firmware of said microprocessor for selectively energizing said compressor motors of said plurality of heat pumps thereof;

said microprocessor sequencing the operation of said compressor motors and said blower motors through relays and electronic switches; and

said microprocessor monitoring the measured temperature signals of said plurality of thermostats and modifying the operating characteristics of said plurality of heat pumps responsive to said measured temperature signals.

33. The thermal zone demand controlled air condition system and electronic system controller of claim 28, wherein said control circuitry and microprocessor logic further comprises:

a plurality of control relays each having an operational coil connected for selective energization by said dc power supply and having power circuits being connected with said ac power supply and power control connections being selectively energized by said ac power supply for control power supply to respective equipment upon dc current energization of the operational coil thereof; and

when said plurality of sources of heating and cooling are heat pumps, a reversing relay having first and second dc power supply circuits being selectively energized by completion of said “

cool”

selector circuit and said “

heat”

selector circuit, said first dc power supply circuit being connected to the coil of the power control relay for a first heat pump and said second dc power supply circuit being connected to the coil of the power control relay for a second heat pump for selection of either of said first and second heat pumps as the primary or secondary heat pump responsive to selective completion of said “

cool” and

“

heat”

selector circuits.

35. The thermal zone demand controlled air conditioning system of claim 28, wherein said plurality of thermostats each comprise:

a controller power supply;

a temperature sensor having an electric power base and having electrical connections to the microprocessor of said electronic system controller with functionality to monitor input temperatures and then output actions to the respective blower motor and to said plurality of sources of heating and cooling;

a power supply conductor having connection with said electric power base and providing electric power supply thereto from said electronic system controller; and

separate sets of electrical relays being selectively energized by said electronic system controller for selectively controlling energization of said blower motor speeds of said thermal zone blower by said electronic system controller for the thermal zone in which said thermostat is located.

36. A thermal zone demand controlled air conditioning system for heating and cooling the air of a building space having a plurality of thermal zones, comprising:

an air circulation system circulating thermally treated air to and return air from said thermal zones and having a conditioned air chamber and a plurality of conditioned air supply conduits each being disposed in air supplying relation with a respective one of said thermal zones of said building space;

a multi-stage thermal source being located externally of said building space;

a heat exchanger located within said air circulation system and having thermal transferring relation with said thermal source;

a plurality of thermal zone blowers and air supply conduits being connected in said air circulation system and conducting conditioned air from said conditioned air chamber through respective conditioned air supply conduits to respective thermal zones of said building space; and

electronic controller circuitry being coupled in staged operational control of said thermal source and thermal demand operation of said plurality of thermal zone blowers controlling said thermal source and said plurality of thermal zone blowers for electronically selected operation of said thermal source and said plurality of thermal zone blowers responsive to the thermal demands of the respective thermal zones of the building space.

37. The thermal zone demand controlled air conditioning system of claim 36, comprising:

said multi-stage thermal source being a water circuit;

at least one pump being connected in said water circuit and causing water flow in said water circuit;

a water chiller being in connection with said water circuit and chilling water flowing therethrough;

a water heater being in connection with said water circuit and selectively adding heat to water flowing therethrough; and

said heat exchanger being a single circuit heat exchanger coil in connection with said water circuit.