Controller for forced-air HVAC system

• US 20050241325A1
• Filed: 04/28/2004
• Published: 11/03/2005
• Est. Priority Date: 04/28/2004
• Status: Active Grant

• Current Assignee: Opto Generic Devices Incorporated
• Original Assignee: Intelligent Power Management Corporation
• Inventors: Olney, Andrew
• Granted Patent: US 7,204,429 B2
• Time in Patent Office: Days
• US Class Current: 62/178
• 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 11/76 by means responsive to temperature, e.g. bimetal springs
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 11/88 Electrical aspects, e.g. circuits
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F25B 2600/112 of evaporator fans
• CPC Class Codes: F25B 2700/2104 of an indoor room or compartment
• CPC Class Codes: F25B 2700/2117 of an evaporator
• CPC Class Codes: F25B 2700/21173 at the outlet
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A forced-air HVAC system has an induction motor that drives its fan or blower. The motor is controlled by a circuit that causes the speed of the fan or blower to vary continuously whenever the HVAC system operates. The controller circuit includes temperature sensors that continuously monitor the temperature of the air the system is delivering. These sensors signal the controller circuit to vary the speed of the fan or blower motor in order to maintain at an optimal level the air temperature in the spaces heated or cooled by the system.

Claims

1. A method of controlling a blower/fan motor in a forced-air HVAC system to maintain a substantially optimal temperature in an interior space, said method comprising the steps of:

measuring a temperature in said interior space;

communicating said substantially optimal temperature to a controller;

when said substantially optimal temperature is higher than said temperature in said interior space, causing said controller to call for heated air from said system;

when said substantially optimal temperature is lower than said temperature in said interior space, causing said controller to call for cooled air from said system;

varying continuously a speed of said blower/fan motor in response to said call for said heated or said cooled air, whereby said blower/fan motor runs substantially continuously once it starts;

said step of varying being responsive to a temperature sensed in a plenum chamber of said system when said call is for said heated air; and

said step of varying being responsive to a temperature sensed in a cooling coil of said system when said call is for said cooled air.

2. The method of claim 1, wherein said system is effective to supply said heated air only.

3. The method of claim 2, wherein said temperature sensed in said plenum chamber is a controlling parameter of said system.

4. The method of claim 1, wherein said system is effective to supply said cooled air only.

5. The method of claim 4, wherein said temperature sensed in said cooling coil is a controlling parameter of said system.

6. The method of claim 1, wherein said system is effective to supply either said heated air or said cooled air.

7. The method of claim 6, wherein, when said controller calls for said heated air, said temperature sensed in said plenum chamber is a controlling parameter of said system, and, when said controller calls for said cooled air, said temperature sensed in said cooling coil is a controlling parameter of said system.

8. Apparatus for controlling a blower/fan motor in a forced-air HVAC system to maintain a substantially optimal temperature in an interior space, said apparatus comprising:

means for measuring a temperature in said interior space;

means for communicating said substantially optimal temperature to a controller;

when said substantially optimal temperature is higher than said temperature in said interior space, said controller being effective to call for heated air from said system;

when said substantially optimal temperature is lower than said temperature in said interior space, said controller being effective to call for cooled air from said system;

said controller being effective to vary continuously a speed of said blower/fan motor in response to said call for said heated or said cooled air, whereby said blower/fan motor runs substantially continuously once it starts;

said controller being further effective to vary said speed of said blower/fan motor in response to a temperature sensed in a plenum chamber of said system when said call is for said heated air; and

said controller being further effective to vary said speed of said blower/fan motor in response to a temperature sensed in a cooling coil of said system when said call is for said cooled air.

9. Apparatus as in claim 8 being effective to supply said heated air only.

10. Apparatus as in claim 9, wherein, when said controller calls for said heated air, said temperature sensed in said plenum chamber is a controlling parameter of said system.

11. Apparatus as in claim 8 being effective to supply said cooled air only.

12. Apparatus as in claim 11, wherein, when said controller calls for said cooled air, said temperature sensed in said cooling coil is a controlling parameter of said system.

13. Apparatus as in claim 8 being effective to supply either said heated air or said cooled air.

14. Apparatus as in claim 13, wherein, when said controller calls for said heated air, said temperature sensed in said plenum chamber is a controlling parameter of said system, and, when said controller calls for said cooled air, said temperature sensed in said cooling coil is a controlling parameter of said system.

15. Apparatus for controlling a blower/fan motor in a forced-air HVAC system to maintain a substantially optimal temperature in an interior space, said apparatus comprising:

a controller effective for varying continuously a speed of said blower/fan motor, whereby said blower/fan motor runs substantially continuously once it starts;

said controller being responsive to at least one of a plenum temperature and a cooling coil temperature; and

said controller being further responsive to a temperature sensor in said interior space, whereby said interior space is kept at a temperature substantially optimal and stable.

16. Apparatus as in claim 15, wherein said controller includes an alternistor.

17. Apparatus as in claim 16, wherein said alternistor is a component of a triggering circuit.

18. Apparatus as in claim 17, wherein said triggering circuit includes an optically-controlled mathematical processing device.

19. Apparatus as in claim 18, wherein said optically-controlled mathematical processing device is responsive to at least two signals.

20. Apparatus as in claim 19, wherein said at least two signals comprise any combination of at least one plenum temperature sensor signal, at least one cooling coil sensor signal, at least one said temperature sensor in said interior space, and at least one system fault sensor.