Condensate trap heater for condensing gas furnace

Patent metadata

Field	Value
Publication number	US-9353993-B2
Application number	US-201313858507-A
Country	US
Kind code	B2
Filing date	Apr 8, 2013
Priority date	Jun 7, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A heating mat for a condensate trap can include resistive traces which heat the mat. The mat can be adhered to the condensate trap, for example using pressure sensitive adhesive. A control thermostat monitors an ambient temperature and/or a temperature within the condensate trap. If a temperature is at or above a setpoint, the controller thermostat disables power to the resistive traces. If a temperature is below at or below a setpoint, the controller thermostat enables power to the resistive traces to heat the condensate trap and the condensate within the condensate trap. In an embodiment, the heating mat can operate at a voltage supplied by the furnace or from a power source external to the furnace.

First claim

The invention claimed is:

1. A heating mat for a furnace condensate trap, comprising;
a resistive heating trace comprising a first end terminating in a first electrode and a second end terminating in a second electrode;
a mat cable electrically coupled to the first electrode and the second electrode, wherein the mat cable is configured to supply power to the heating mat during operation of the heating mat; and
an adhesive configured to attach the heating mat to one or more external surfaces of a furnace condensate trap, wherein the heating mat has a thickness between about 0.67 mm and about 1.5 mm and is configured to prevent freezing of water within the furnace condensate trap.

2. The heating mat of claim 1 , wherein the mat cable is configured to supply about 24V to the resistive heating trace during operation of the heating mat.

3. The heating mat of claim 1 , wherein the mat cable is configured to receive about 24V from a transformer within a furnace.

4. The heating mat of claim 1 , wherein the mat cable is configured to receive about 24V from a power source that is external to the furnace.

5. The heating mat of claim 1 , further comprising a cutout configured to receive a condensate drain pipe which extends from a face of a furnace condensate trap.

6. The heating mat of claim 1 , further comprising:
only a single section configured to cover only a single face of a furnace condensate trap, wherein the resistive heating trace extends and meanders across the single section of the heating mat to heat an interior of the furnace condensate trap through only the single face.

7. The heating mat of claim 1 , further comprising:
a first section configured to cover a front face of a furnace condensate trap;
a second section configured to cover a first side of the furnace condensate trap;
a third section extending continuously from the second section and configured to cover a third side of the furnace condensate trap;
a fourth section configured to cover a back face of the furnace condensate trap which is opposite the front face; and
a fifth section configured to cover a second side of the furnace condensate trap which is opposite the first side,
wherein the resistive heating trace extends and meanders across each of the first section, the second section, the third section, the fourth section, and the fifth section and the heating mat is configured to heat an interior of the furnace condensate trap through the front face, the first side, the back face, the second side and the third side.

8. The heating mat of claim 7 , wherein:
the second section is directly connected to the first section, the third section, and the fourth section;
the fifth section is directly connected to the fourth section; and
the third section is configured to cover a bottom of the furnace condensate trap.

9. The heating mat of claim 1 , further comprising:
a control thermostat configured to enable power to the heating trace when the control thermostat senses a temperature which is at or below a setpoint and to disable power to the heating trace when the control thermostat senses a temperature which is at or above the setpoint.

10. The heating mat of claim 9 , wherein the control thermostat is integrated into the mat cable.

11. The heating mat of claim 1 , further comprising:
a control thermostat configured to enable power to the heating trace upon receipt of a first temperature which is below a setpoint from a temperature sensor located within a furnace condensate trap, and further configured to disable power to the heating trace upon receipt of a second temperature which is above a setpoint from the temperature sensor located within the furnace condensate trap.

12. A furnace condensate trap, comprising:
a condensate trap body for storing a condensate;
a condensate input pipe attached to the condensate trap body and configured to receive the condensate;
a condensate output pipe attached to the condensate trap body and configured to drain the condensate from the furnace condensate trap;
a heating mat attached to one or more external surfaces of the condensate trap body with an adhesive and comprising:
a resistive heating trace; and
a heater cable electrically coupled to the resistive heating trace,

wherein the heater cable is configured to supply power to the resistive heating trace during operation of the furnace condensate trap and the heating mat is configured to prevent freezing of water within the furnace condensate trap.

13. The condensate trap of claim 12 , wherein the heater cable is configured to supply about 24V to the resistive heating trace during operation of the heater.

14. The condensate trap of claim 12 , wherein the heater cable is configured to receive about 24 V from a transformer within a furnace.

15. The condensate trap of claim 12 , wherein the heater further comprises a cutout and the condensate output pipe extends through the cutout.

16. The condensate trap of claim 12 , wherein the heating mat comprises:
a first section configured to cover a front face of the condensate trap body;
a second section configured to cover a first side of the condensate trap body;
a third section extending continuously from the second section and configured to cover a third side of the condensate trap body;
a fourth section configured to cover a back face of the condensate trap body which is opposite the front face; and
a fifth section configured to cover a second side of the condensate trap body which is opposite the first side,
wherein the resistive heating trace extends and meanders across each of the first section, the second section, the third section, the fourth section, and the fifth section and the heating mat is configured to heat an interior of the furnace condensate trap through the front face, the first side, the back face, the second side and the third side.

Assignees

• Carrier Corp

Inventors

• Warmuth David D

Classifications

• F27D7/00 Primary

  Forming, maintaining or circulating atmospheres in heating chambers · CPC title

• H05B2203/002

  Heaters using a particular layout for the resistive material or resistive elements · CPC title

• F24D19/0095

  Devices for preventing damage by freezing · CPC title

• H05B2214/02

  Heaters specially designed for de-icing or protection against icing · CPC title

• F24H8/006 Primary

  Means for removing condensate from the heater · CPC title