Selectable efficiency versus comfort for modulating furnace

• US 9,316,413 B2
• Filed: 06/11/2008
• Issued: 04/19/2016
• Est. Priority Date: 06/11/2008
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Nordberg, Timothy J., Chian, Brent, Bird, Douglas D., Schultz, Michael W., Anderson, Peter M.
• Primary Examiner(s): PEREIRO, JORGE ANDRES
• Application Number:
  US12/137,212
• Publication Number:
  US 20090308372A1
• Time in Patent Office: 2,869 Days
• Field of Search: 126/116.A, 126/99.R
• US Class Current: 1/1
• CPC Class Codes: F23N 2223/44 Optimum control
• CPC Class Codes: F23N 3/082 using electronic means
• CPC Class Codes: F24D 19/1084 for air heating systems
• CPC Class Codes: F24H 15/156 Reducing the quantity of energy consumed; Increasing efficiency
• CPC Class Codes: F24H 15/176 Improving or maintaining comfort of users
• CPC Class Codes: F24H 15/208 Temperature of the air after heating
• CPC Class Codes: F24H 15/238 Flow rate
• CPC Class Codes: F24H 15/281 Input from user
• CPC Class Codes: F24H 15/31 of valves having only one inlet port and one outlet port, e.g. flow rate regulating valves
• CPC Class Codes: F24H 15/33 Control of dampers
• CPC Class Codes: F24H 15/35 Control of the speed of fans
• CPC Class Codes: F24H 15/45 remotely accessible
• CPC Class Codes: F24H 9/2085 using fluid fuel
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies

Abstract

A furnace controller for a modulating furnace that helps provide a balance between energy efficiency and occupant comfort across various burner firing rates and/or across various circulating blower speeds. In some cases, the furnace controller can be configured to permit a user to customize operation of the furnace in accordance with their particular needs and/or desires with respect to efficiency and comfort. A selection may be made between an energy efficiency setting and a user comfort setting. Then, a plenum parameter such as a discharge air temperature (DAT) or discharge air flow (DAF) may be regulated in accordance with the selected setting.

Claims

1. A method of operating a modulating forced air furnace, the method comprising the steps of:

accessing a defined relationship between a circulating blower speed and a plenum temperature, wherein the plenum temperature has a non-constant relationship with the circulating blower speed over at least a range of circulating blower speeds;

operating the modulating forced air furnace in accordance with the defined relationship between the circulating blower speed and the plenum temperature such that a substantially non-constant plenum temperature is produced over at least a range of circulating blower speeds.

2. The method of claim 1, wherein operating the modulating forced air furnace in accordance with the defined relationship between a circulating blower speed and a plenum temperature comprises adjusting a burner firing rate.

3. The method of claim 2, wherein operating the modulating forced air furnace in accordance with the defined relationship between a circulating blower speed and a plenum temperature further comprises adjusting the circulating blower speed.

4. A method of operating a modulating forced air furnace, the method comprising the steps of:

allowing a selection of an efficiency/comfort setting;

accessing a defined relationship between a burner firing rate and a plenum parameter, wherein the plenum parameter has a non-constant relationship with the burner firing rate over at least a range of burner firing rates, and wherein for a given burner firing rate, the corresponding plenum parameter is dependent upon the selected efficiency/comfort setting;

operating the modulating forced air furnace in accordance with the defined relationship between the burner firing rate and the plenum parameter.

5. The method of claim 4, wherein operating the modulating forced air furnace in accordance with the defined relationship between the burner firing rate and the plenum parameter comprises controlling a circulating blower speed.

6. The method of claim 4, wherein the defined relationship between the burner firing rate and the plenum parameter comprises a linear relationship with a non-zero slope between the burner firing rate and the plenum parameter.

7. The method of claim 4, wherein the plenum parameter corresponds to a plenum temperature.

8. The method of claim 4, wherein the plenum parameter corresponds to a volumetric plenum air flow measurement.

9. A method of operating a modulating furnace comprising a variable rate burner, a variable rate circulating blower and a furnace controller, the method comprising the steps of:

selecting between an energy efficiency setting and a user comfort setting;

the furnace controller operating the modulating furnace in accordance with a predetermined algorithm, and the selected setting alters the predetermined algorithm;

regulating a plenum parameter in accordance with the selected setting, wherein the plenum parameter is related to a discharge air temperature (DAT) of the modulating furnace; and

wherein regulating the plenum parameter in accordance with the selected setting comprises operating the variable rate circulating blower and/or the variable rate burner in accordance with the selected setting.

10. The method of claim 9, wherein operating the modulating furnace in accordance with the predetermined algorithm comprises adjusting a speed of the variable rate circulating blower in order to obtain a plenum parameter that is related to a current firing rate of the variable rate burner.

11. The method of claim 10, wherein the speed of the variable rate circulating blower is adjusted in order to obtain a plenum parameter in accordance with a linear relationship between the plenum parameter and the current firing rate.

12. The method of claim 10, wherein operating the modulating furnace in accordance with the energy efficiency setting comprises operating the modulating furnace with a circulating blower speed profile that improves efficiency at the expense of user comfort.

13. The method of claim 10, wherein operating the modulating furnace in accordance with the user comfort setting comprises operating the modulating furnace with a circulating blower speed profile that improves comfort at the expense of energy efficiency.

14. The method of claim 9, wherein operating the modulating furnace in accordance with the predetermined algorithm comprises adjusting a firing rate of the variable rate burner in order to obtain a discharge air temperature (DAT) that is related to a speed of the variable rate circulating blower.

15. The method of claim 14, wherein operating the modulating furnace in accordance with the energy efficiency setting comprises operating the modulating furnace with a burner rate profile that improves efficiency at the expense of user comfort.

16. The method of claim 14, wherein operating the modulating furnace in accordance with the user comfort setting comprises operating the modulating furnace with a burner rate profile that improves comfort at the expense of energy efficiency.

17. The method of claim 9, wherein regulating the plenum parameter comprises regulating a plenum temperature or regulating a plenum volumetric air flow.

18. The method of claim 9, wherein selecting an energy efficiency setting or a user comfort setting comprises setting an input selector or making a software setting.