Anti-fog heat control for a refrigerated merchandiser

Patent metadata

Field	Value
Publication number	US-10178918-B2
Application number	US-201313794961-A
Country	US
Kind code	B2
Filing date	Mar 12, 2013
Priority date	Mar 12, 2013
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

A refrigerated merchandiser includes a sensor coupled to a case adjacent an air inlet. The sensor is in communication with a portion of a refrigerated airflow passing through the air inlet to sense a temperature of the airflow and to generate a signal indicative of an air return temperature. The merchandiser also includes a controller in communication with the sensor to receive the signal indicative of the air return temperature, the controller further in communication with a conductive film on a door and programmed to initiate a clearing interval to clear condensation from the door in response to the signal indicative of the air return temperature reaching a first predetermined temperature threshold.

First claim

The invention claimed is:

1. A refrigerated merchandiser comprising:
a case defining a product display area and including a base having an air inlet located adjacent the product display area and a canopy disposed substantially above the product display area, the canopy having an air outlet located adjacent the product display area, the case further including a mullion defining an opening in communication with the product display area;
a door coupled to the case over the opening to provide access to the product display area and to substantially enclose the product display area, the door including a glass member having a conductive film;
a passageway fluidly connecting the air inlet with the air outlet to direct a refrigerated airflow from the air outlet across the opening and generally toward the air inlet;
a first sensor coupled to the case adjacent the air inlet and in communication with a portion of the refrigerated airflow passing through the air inlet to sense a temperature of the airflow and to generate a signal indicative of an air return temperature;

a second sensor; and
a controller in communication with the first sensor to receive the signal indicative of the air return temperature and in communication with the second sensor to receive the signal indicative of the glass temperature, the controller further in communication with the conductive film and programmed to initiate a clearing interval to clear condensation from the door in response to the signal indicative of the air return temperature reaching a first predetermined temperature threshold,
wherein the controller is programmed to heat the door until the second sensor detects that the glass temperature has reached a glass temperature threshold.

2. The refrigerated merchandiser of claim 1 , wherein the door is a first door and the case further includes a second door positioned adjacent the first door and a conductive film disposed on the adjacent door, wherein the controller is programmed to heat the door and the adjacent door in response to the signal from the first sensor indicative of the air return temperature reaching the first predetermined temperature threshold.

3. The refrigerated merchandiser of claim 1 , wherein the conductive film is coupled to an interior surface of the glass member facing the product display area.

4. The refrigerated merchandiser of claim 1 , wherein the first sensor is mounted beneath an air intake grill.

5. The refrigerated merchandiser of claim 1 , wherein the controller is further programmed to pulse heat applied to the door in response to the second sensor detecting that the glass temperature has reached the glass temperature threshold.

6. The refrigerated merchandiser of claim 5 , wherein the controller is programmed to maintain the glass temperature at the glass threshold temperature in response to the second sensor detecting that the glass temperature has reached the glass temperature threshold.

7. The refrigerated merchandiser of claim 1 , wherein the controller is programmed to stop the clearing interval in response to the air return temperature for the first door decreasing beyond a second air threshold temperature.

8. The refrigerated merchandiser of claim 7 , wherein the first predetermined temperature threshold is between approximately 30-38° Fahrenheit.

9. The refrigerated merchandiser of claim 7 , wherein the second predetermined temperature threshold is between approximately 30-38° Fahrenheit.

10. The refrigerated merchandiser of claim 7 , wherein the glass temperature threshold is between approximately 55-70° Fahrenheit.

11. A method of operating a refrigerated merchandiser including a case defining a product display area, and at least one door providing access to the product display area, the method comprising:
sensing an air return temperature inside the case via a first sensor positioned adjacent an air return inlet of the case and in fluid communication with at least a portion of a refrigerated airflow passing through the air inlet;
generating a signal indicative of the air return temperature via the first sensor;
determining whether the signal is indicative of the air return temperature reaching a first predetermined temperature threshold via a controller in communication with the first sensor; and
initiating a clearing interval via the controller to clear condensation from the door in response to the signal indicating that the air return temperature has reached the first predetermined temperature threshold;
sensing a glass temperature of the door via a second sensor;
generating a signal indicative of the glass temperature via the second sensor; and
controlling the clearing interval based on the glass temperature signal.

12. The method of claim 11 , wherein initiating the clearing interval includes pulsing the heat applied to the door.

13. The method of claim 11 , wherein the door is a first door and the case further includes a second door positioned adjacent the first door, the method further including initiating a clearing interval on the adjacent door in response to the signal indicative of the air return temperature reaching the first predetermined temperature threshold.

14. The method of claim 11 , further comprising:
continuously heating a surface of a door at least partially enclosing the product display area in response to the signal indicative of the air return temperature reaching the first predetermined temperature threshold;
sensing the glass temperature on the door and generating the signal indicative of the glass temperature;
pulsing the heat applied to the surface of the door in response to the glass temperature reaching a glass threshold temperature; and
initiating a clearing interval on a second door positioned adjacent the first door.

15. The method of claim 14 , wherein initiating the clearing interval on the second door includes continuously heating the second door in response to the signal indicative of the air return temperature reaching the first predetermined temperature threshold.

16. The method of claim 15 , further comprising pulsing the heat applied to a surface of the second door in response to the glass temperature reaching the glass threshold temperature.

17. The method of claim 16 , further comprising simultaneously initiating the clearing interval on the first door and the second door.

18. A method of operating a refrigerated merchandiser including a case defining a product display area, and at least one door providing access to the product display area, the method comprising:
sensing an air return temperature inside the case;
generating a signal indicative of the air return temperature;
determining whether the signal is indicative of the air return temperature reaching a first predetermined temperature threshold; and
initiating a clearing interval to clear condensation from the door in response to the signal indicating that the air return temperature has reached the first predetermined temperature threshold,

wherein initiating a clearing interval includes raising a temperature of the door to a glass threshold temperature, and maintaining the temperature of the door at the glass threshold temperature for a predetermined period of time.

Assignees

• Hussmann Corp

Inventors

• Rasch John M

Classifications

• F25D23/02

  Doors; Covers (F25D23/08 takes precedence {locks or fastenings E05B65/0042}) · CPC title

• A47F3/0434

  Glass or transparent panels · CPC title

• H05B2203/013

  Heaters using resistive films or coatings · CPC title

• H05B3/84

  Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields · CPC title

• A47F3/0478 Primary

  Control or safety arrangements · CPC title