Water heater energy savings algorithm for reducing cold water complaints

• US 20070179678A1
• Filed: 01/30/2006
• Published: 08/02/2007
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Kasprzyk, Donald, Nordberg, Timothy, Munsterhuis, Sybrandus
• Granted Patent: US 8,165,726 B2
• Time in Patent Office: Days
• US Class Current: 700/300
• CPC Class Codes: F24H 15/156 Reducing the quantity of energy consumed; Increasing efficiency
• CPC Class Codes: F24H 15/175 where the difference between the measured temperature and a set temperature is kept under a predetermined value
• CPC Class Codes: F24H 15/225 at different heights of the tank
• 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 15/36 of burners
• CPC Class Codes: F24H 9/2035 using fluid fuel
• CPC Class Codes: G05D 23/1917 using digital means

Abstract

An energy savings water heater is described. The water heater is controlled by an energy savings algorithm that uses one or more of a variable setpoint differential, a variable setback threshold, additional setback thresholds, and an adjustable minimal setpoint to improve the operation of an energy efficient water heater. Additionally or alternatively, a different setback control algorithm may be used that obtains additional data to adjust the setpoint. As a result, the operating cost of the water heater is reduced, while minimizing user complaints of cold water.

Claims

1. A water heater system, comprising in combination:

a tank containing water;

at least one heater for heating the water in a tank; and

a controller that adjusts a minimum setpoint of the at least one heater as a function of a user setting.

2. The system of claim 1, wherein the minimum setpoint of the at least one heater increases as the user setting increases.

3. The system of claim 1, wherein the controller adjusts the minimum setpoint of the at least one heater based on the following equation:

SP_min=Knob_min+(Knob_current−

Knob_min)/2

where SP_min is the minimum setpoint;

Knob_min is a user'"'"'s minimum setting; and

Knob_current is a user'"'"'s current setting.

4. The system of claim 1, wherein the controller adjusts the minimum setpoint of the at least one heater to be approximately half way between a current user setting and a minimum user setting.

5-20. -20. (canceled)