Multi-zone automatic changeover heating, cooling and ventilating control system

• US 5,860,473 A
• Filed: 07/12/1994
• Issued: 01/19/1999
• Est. Priority Date: 07/12/1994
• Status: Expired due to Term

• Current Assignee: Trol-A-Temp Division Of Trolex Corp.
• Original Assignee: Trol-A-Temp Division Of Trolex Corp.
• Inventors: Seiden, Lewis Jim
• Primary Examiner(s): Ford, John K.
• Application Number:
  US08/274,096
• Time in Patent Office: 1,652 Days
• Field of Search: 236/1 B, 236/1 C, 236/49.3, 236/11, 165/217, 165/208, 165/209
• US Class Current: 165/208
• 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 11/54 using one central controller connected to several sub-controllers
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: G05D 23/1904 variable in time
• CPC Class Codes: G05D 23/1934 each space being provided with one sensor acting on one or more control 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

A climate control system having a control means for receiving cool call signals and heat call signals from a plurality of thermostats. The control means blocking action by conflicting calls when the system is in a heat mode or cool mode. The system also preventing a single zone from dominating the mode of the control system and allow a conflicting call to be received after the control system has been in a particular mode for a maximum period or the conflicting call has been waiting for longer than a maximum period. The control system also properly adjusting the dampers to allow purging of ducts after heating and cooling mode and to allow zone or system ventilation upon request.

Claims

1. A climate control system comprising:

a first zone;

a first thermostat positioned in said first zone, said first thermostat including temperature switch means for generating a cool call signal when a temperature in said first zone is above a first predetermined value, said temperature switch means generating a heat call signal when a temperature in said first zone is below a second predetermined value;

a second zone;

a second thermostat positioned in said second zone, said thermostat including temperature switch means for generating a cool call signal when a temperature in said second zone is above another first predetermined value, said temperature switch means generating a heat call signal when a temperature in said second zone is below another second predetermined value;

control means for receiving said cool call signals and said heat call signals from said first and second thermostats, said control means generating a cool mode signal if one of said cool call signals is received before one of said heat call signals, said control means blocking generation of said heat mode signal when said cool mode signal is generated, said control means also generating a heat mode signal if one of said heat call signals is received before one of said cool call signals, said control means blocking generation of said cool mode signal when said mode signal when said heat mode signal is generated;

said control means generating first open and close damper signals and second open and close damper signal, said control means generating said open damper signals when a corresponding zone generates a call signal corresponding to a present mode signal, said control means generating said close damper signals when a corresponding zone generates a call signal contrary to said present mode signal;

said first and second thermostats include a first power terminal, a heat call terminal and a cool call terminal, said temperature switch means of said first and second thermostats connects said first power terminal to said heat call terminal when said temperature in a respective zone is below a respective predetermined value, said temperature switch means of said first and second thermostats connects said first power terminal to said cool terminal when said temperature in said respective zone is above said respective predetermined value;

said control means includes a multi-zone panel means with a first zone heat call relay, a first zone cool call relay, a second zone heat call relay and a second zone cool call relay, said first zone heat call relay having a first coil terminal connected to said heat call terminal of said first thermostat and a second coil terminal connected to a heat allowance bus, said second zone heat call relay having a first coil terminal connected to said heat call terminal of said second thermostat and a second coil terminal connected to said heat allowance bus, said first zone cool call relay having a first coil terminal connected to said cool call terminal of said first thermostat and a second coil terminal connected to a cool allowance bus, said second zone cool call relay having a first coil terminal connected to said cool call terminal of said second thermostat and a second coil terminal connected to said cool allowance bus;

said control means also includes a master control module having a heat mode relay, a cool mode relay, a heat active relay and a cool active relay, said heat mode relay having a first normally closed contact set with a first terminal connected to said cool allowance bus and a second terminal, said heat active relay having a first normally closed contact set with a first terminal connected to said second terminal of said heat mode relay and a second terminal connected to a second power terminal, said cool mode relay having a first normally closed contact set with a first terminal connected to said heat allowance bus and a second terminal, said cool active relay having a first normally closed contact set with a first terminal connected to said second terminal of said cool mode relay and a second terminal connected to said second power terminal.

2. A climate control system in accordance with claim 1, wherein:

said first and second thermostats each include fan switch means for generating a separate fan call signal from each zone;

said control means blocking generation of said fan call signals when one of said heat mode signal and said heat active signal are generated, said control means receiving and generating a fan mode signal if neither of said heat mode and said cool mode signals are present.

3. A climate control system in accordance with claim 1, wherein:

said control means includes a separate system/zone switch means for said first and second zones to generate a zone ventilation signal or a system ventilation signal, said control means generating said close damper signals for corresponding zones not generating said fan call signal when said zone ventilation signal is present.

4. A climate control system in accordance with claim 1, wherein:

said control means includes a timer means for receiving said heat mode call signal and said cool mode call signal, and for generating a cool active signal when receiving said cool mode signal, said timer means also generating a heat active signal when receiving said heat mode signal;

said control means blocking said heat call signal from said first and second thermostats when said control means is generating one of said cool mode signal and said cool active signal, said control means also blocking said cool call signal from said first and second thermostats when said control means is generating one of said heat mode signal and said heat active signal.

5. A climate control system in accordance with claim 4, wherein:

said timer means generates both said cool active signal and said heat active signal substantially immediately after one of said heat and cool mode signals has been removed, said generating of said both active signals existing for a purge period to remove residual heat.

6. A climate control system in accordance with claim 4, wherein:

said timer means generating both said cool active signal and said heat active signal after one of said mode signals has been generated for longer than a predetermined max time, said generating of said both cool and heat active signals blocking generation of said mode signals, said generating of said both active signals existing for a purge period to remove residual heat.

7. A climate control system in accordance with claim 4, wherein:

said timer means generating both said cool active signal and said heat active signal after one of said mode signals has been blocked for longer than a predetermined max time, said generating of said both cool and heat active signals blocking generation of said mode signals, said generating of said both active signals existing for a purge period to remove residual heat.

8. A climate control system in accordance with claim 4, wherein:

said timer means generates said cool active signal after said heat mode signal has been generated for longer than a predetermined max period, said generating of said cool active signal removing said heat mode signal, said timer means removing said heat active signal after said max period and continuing to generate said cool active signal for a bias period to block generation of said heat call signals, and to enable generation of said cool call signals and generation of said cool mode signal during said bias period.

9. A climate control system in accordance with claim 4, wherein:

said timer means generates said cool active signal after said cool mode signal has been blocked for longer than a predetermined max period, said generating of said cool active signal removing said heat mode signal, said timer means removing said heat active signal after said max period and continuing to generate said cool active signal for a bias period to block generation of said heat call signals, and to enable generation of said cool call signals and generation of said cool mode signal during said bias period.

10. A climate control system in accordance with claim 4, wherein:

said first and second thermostats each include fan switch means for generating a separate fan call signal from each zone;

said control means includes a separate system/zone switch means for said first and second zones to generate a zone ventilation signal or a system ventilation signal, said control means includes an idle switch means switchable between a damper open state and a damper closed state for each of said first and second zones;

said control means generating said open and close damper signals for corresponding zones in accordance with a logic based on said signals and having a form of OPEN=(A*I'"'"')+(B*J'"'"')+( A*I'"'"'!'"'"'* B*J'"'"'!'"'"'* K'"'"'*C'"'"'*{D+(D'"'"'*E'"'"'*F)}!)) CLOSE=A'"'"'*B'"'"'*K'"'"'*(C+ C'"'"'*D'"'"'*{ (E'"'"'*F'"'"')+E!) where,

*=logical AND function,

+=logical OR function,

'"'"'=signal not present,

A=corresponding zone cool call signal,

B=corresponding zone heat call signal,

C=system CAC=G+H(cool mode OR heat mode)=(I*J'"'"')+(J*I'"'"')

D=corresponding zone fan call signal

E=fan CAC signal=D* corresponding zone ventilation signal

F=corresponding zone idle switch means in damper open state (F'"'"' is closed state),

G=cool mode signal=(A*B'"'"'*H'"'"')+(G*A*B*MTIME),

H=heat mode signal=( B*A'"'"'*G'"'"')+( H*A*B*MTIME),

I=heat active signal (cool mode prevention signal)=H+(I*H'"'"'*PTIME)+(J*G'"'"'*PTIME),

J=cool active signal (heat mode prevention signal)=G+(J*G'"'"'*PTIME)+(I*H'"'"'*PTIME),

K=purge=I*J'"'"'(heat active AND cool active),

MTIME=within maximum time period that the system can be in heat or cool mode,

PTIME=within purge time period.

11. A climate system comprising:

a first zone;

a first thermostat positioned in said first zone, said first thermostat including temperature switch means for generating a cool call signal when a temperature in said first zone is above a first predetermined value, said temperature switch means generating a heat call signal when a temperature in said first zone is below a second predetermined value;

a second zone;

a second thermostat positioned in said second zone, said thermostat including temperature switch means for generating a cool call signal when a temperature in said second zone is above another first predetermined value, said temperature switch means generating a heat call signal when a temperature in said second zone is below another second predetermined value;

control means for receiving said cool call signals and said heat call signals from said first and second thermostats, and for generating a cool mode signal when receiving said cool call signal from one of said first and second thermostats and not receiving said heat call signals, said control means blocking generation of a heat mode signal when said cool mode signal is generated, said control means also generating said heat mode signal when receiving said heat call signal from one of said first and second thermostats and not receiving said cool call signals, said control means blocking generation of said cool mode signal when said heat mode signal is generated;

said first and second thermostats include a first power terminal, a heat call terminal and a cool call terminal, said temperature switch means of said first and second thermostats connects said first power terminal to said heat call terminal when said temperature in a respective zone is below a respective predetermined value, said temperature switch means of said first and second thermostats connects said first power terminal to said cool call terminal when said temperature in said respective zone is above said respective predetermined value;

said control means includes a multi-zone panel means with a first zone heat call relay, a first zone cool call relay, a second zone heat call relay and a second zone cool call relay, said first zone heat call relay having a first coil terminal connected to said heat call terminal of said first thermostat and a second coil terminal connected to a heat allowance bus, said second zone heat call relay having a first coil terminal connected to said heat call terminal of said second thermostat and a second coil terminal connected to said heat allowance bus, said first zone cool call relay having a first coil terminal connected to said cool call terminal of said first thermostat and a second coil terminal connected to a cool allowance bus, said second zone cool call relay having a first coil terminal connected to said cool call terminal of said second thermostat and a second coil terminal connected to said cool allowance bus;

said control means also includes a master control module having a heat mode relay, a cool mode relay, a heat active relay and a cool active relay, said heat mode relay having a first normally closed contact set with a first terminal connected to said cool allowance bus and a second terminal, said heat active relay having a first normally closed contact set with a first terminal connected to said second terminal of said heat mode relay and a second terminal connected to a second power terminal, said cool mode relay having a first normally closed contact set with a first terminal connected to said heat allowance bus and a second terminal, said cool active relay having a first normally closed contact set with a first terminal connected to said second terminal of said cool mode relay and a second terminal connected to said second power terminal.

12. A climate control system in accordance with claim 11, wherein:

said cool mode relay has a second normally closed contact set with a first terminal connected to said first power terminal and a second terminal, a first coil terminal of said heat mode relay being connected to a heat call bus, said first zone heat call relay having a first normally open contact set with a first terminal connected to said heat call bus and a second terminal connected to said second power terminal, said second zone heat call relay having a first normally open contact set with a first terminal connected to said heat call bus and a second terminal connected to said second power terminal;

said heat mode relay has a second normally closed contact set with a first terminal connected to said first power terminal and a second terminal, a first coil terminal of said cool mode relay being connected to a cool call bus, said first zone cool call relay having a first normally open contact set with a first terminal connected to said cool call bus and a second terminal connected to said second power terminal, said second zone cool call relay having a first normally open contact set with a first terminal connected to said cool call bus and a second terminal connected to said second power terminal.

13. A climate control system in accordance with claim 12, wherein:

conductivity of said first coil terminal of said cool mode relay with said first power terminal and conductivity of said second coil terminal of said cool mode relay with said second power terminal generates said cool mode signal;

conductivity of said first coil terminal of said heat mode relay with said first power terminal and conductivity of said second coil terminal of said heat mode relay with said second power terminal generates said heat mode signal;

said cool active signal energizes said cool active relay;

said heat active signal energizes said heat active relay.

14. A climate control system in accordance with claim 12, wherein:

each of said first and second thermostats include a fan call terminal and fan switch means for generating a fan call signal, said fan switch means connects said first power terminal to said fan call terminal;

a first damper is connected to said first zone, said first damper being movable between an open position and a closed position, said first damper having a close terminal which closes said first damper when said close terminal is connected to said first power terminal, said first damper having an open terminal which opens said first damper when said open terminal is connected to said first power terminal;

a second damper is connected to said second zone, said second damper being movable between an open position and a closed position, said second damper having a close terminal which closes said second damper when said close terminal is connected to said first power terminal, said second damper having an open terminal which opens said second damper when said open terminal is connected to said first power terminal;

said first zone cool call relay includes a second normally open contact set with a first terminal connected to said first power terminal and a second terminal connected to said open terminal of said first damper, said first zone cool call relay also includes a first normally closed contact set with a first terminal connected to said first power terminal and a second terminal;

said first zone heat call relay includes a second normally open contact set with a first terminal connected to said second terminal of said first zone cool call relay first normally closed contact set and a second terminal connected to said open terminal of said first damper, said first zone heat call relay also includes a first normally closed contact set with a first terminal connected to said second terminal of said first zone cool call relay first normally closed contact set and a second terminal;

said cool active relay includes a second normally closed contact set with a first terminal connected to said second terminal of said first normally closed contact set of said first zone heat call relay and a second terminal;

said heat active relay includes a second normally closed contact set with a first terminal connected to said second terminal of said second normally closed contact set of said cool active relay and a second terminal;

said multi-zone panel means includes a system CAC, said system CAC relay including a first coil terminal connected to said first power terminal and a second coil terminal connected to one of a first terminal of a fan normally open contact set of said heat mode relay and said cool mode relay, said system CAC relay including a normally closed contact set with a first terminal connected to said second terminal of said second normally closed contact set of said heat active relay and a second terminal connected to said close terminal of said first damper, said system CAC relay including a normally open contact set with a first terminal connected to said second terminal of said second normally closed contact set of said heat active relay and a second terminal;

said multi-zone panel means includes a first zone fan relay, said first zone fan relay including a first coil terminal connected to said fan call terminal of said first thermostat and a second coil terminal connected to said cool allowance bus, said first zone fan relay including a normally closed contact set with a first terminal connected to said second terminal of said normally closed contact set of said system CAC relay and a second terminal, said first zone fan relay including a normally open contact set with a first terminal connected to said second terminal of said normally closed contact set of said system CAC relay and a second terminal connected to said open terminal of said first damper;

said multi-zone panel means includes a system fan bus;

said multi-zone panel means includes a system fan relay, said system fan relay including a first coil terminal connected to said first power terminal and a second coil terminal connected to said system fan bus, said system fan relay including a normally closed contact set with a first terminal connected to said second terminal of said normally closed contact set of said first zone fan relay and a second terminal, said system fan relay including a normally open contact set with a first terminal connected to said second terminal of said normally closed contact set of said first zone fan relay and a second terminal connected to said close terminal of said first damper;

said multi-zone panel means including an idle switch having a first throw terminal connected to said open terminal of said first damper and a second throw terminal connected to said close terminal of said first damper, said idle switch also having a pull terminal connected to said second terminal of said normally closed contact set of said system fan relay;

said multi-zone panel means includes a second zone fan relay, said second zone fan relay including a first coil terminal connected to said fan call terminal of said second thermostat and a second coil terminal connected to said cool allowance bus, said second zone fan relay including a normally opened contact set with a first terminal connected to said second power terminal and a second terminal;

said multi-zone panel means includes a system/zone switch with a first terminal connected to said second terminal of said normally open contact set of said second zone fan relay, and a second terminal connected to said system fan bus.

15. A climate control system in accordance with claim 11, wherein:

each of said first and second thermostats include a fan call terminal and fan switch means for generating a fan call signal;

a first damper is connected to said first zone, said first damper being movable between an open position and a closed position;

a second damper is connected to said second zone, said second damper being movable between an open position and a closed position;

said control means receiving said fan call signals from said first and second thermostats, said control means including system/zone switch means for selectively generating a zone only fan signal for each of said fan call signals, said control means opening said first damper when receiving one of said first heat or cool call signals, said control means closing said first damper when generating one of said heat or cool mode signals and not receiving one of said first heat or cool call signals, said control means placing said first damper in a ventilation state when said control means is not generating one of said heat or cool mode signals and not receiving one of said first heat or cool call signals, said control means opening said first damper when said first damper is in said ventilation state and receiving said fan call signal from said first thermostat, said control means closing said first damper when said first damper is in said ventilation state, not receiving said fan call signal from said first thermostat and generating said zone only fan signal from said second thermostat.

16. A climate control system in accordance with claim 15, wherein:

said control means has a purge period, and said control means maintains a position of said first and second dampers constant from an immediately previous period though said purge period.