Condensate Pump

• US 20110061415A1
• Filed: 12/14/2009
• Published: 03/17/2011
• Est. Priority Date: 03/25/2005
• Status: Active Grant

• Current Assignee: DiversiTech Corporation (DiversiTech Holdings, Inc.)
• Original Assignee: DiversiTech Corporation (DiversiTech Holdings, Inc.)
• Inventors: Ward, Charles Barry
• Granted Patent: US 8,651,824 B2
• Time in Patent Office: Days
• US Class Current: 62/291
• CPC Class Codes: F04B 49/04 Regulating by means of floats F04B49/025 takes precedence
• CPC Class Codes: F24F 13/22 Means for preventing condensation or evacuating condensate
• CPC Class Codes: F24F 13/222 for evacuating condensate
• CPC Class Codes: Y10T 137/85986 Pumped fluid control

Abstract

A condensate pump for an HVAC system includes a reservoir for collecting condensate water, a pump motor connected to an impeller pump for pumping the condensate water out of the reservoir, and a floatless pump control module. The floatless pump'"'"'s microcontroller detects the water level in the reservoir and, based on the water level in the reservoir, controls the operation of the pump motor, and if necessary, sounds an alarm and shuts down the HVAC system. The floatless pump microcontroller may employ an ultrasonic transducer or capacitance sensors to detect the level of condensate water in the reservoir. The microcontroller implements a variable water lift feature to pump the water using the lowest possible speed for the pump. The microcontroller implements a self-cleaning feature to pump stagnant water out of the reservoir and to pulse water in the drain line and the agitation of the water in the reservoir. The microcontroller implements an anti-clog feature to clear a clogged drain line when an overflow condition is detected.

Claims

1. In a condensate pump for an HVAC system having a reservoir for collecting condensate water and a pump motor connected to an impeller pump within the reservoir for pumping the condensate water out of the reservoir through a drain line with an outlet at an elevation above the pump, a floatless condensate pump control module comprising:

a. a floatless water level sensor for detecting the level of water in the reservoir;

b. a variable pump motor control switch for starting, stopping, and controlling the speed of the pump motor; and

c. a microcontroller for controlling the operation of the variable pump motor control switch, in response to the detected water level, the microcontroller implementing the steps of;

i. monitoring of the water level sensor and detecting when the water in the reservoir has reached an intermediate level;

ii. in response to the water reaching the intermediate level, starting the pump motor at a first low speed; and

iii. increasing the speed of the pump motor until the speed of the pump motor is sufficient to pump the water out of the reservoir through the drain line to the elevation of the outlet of the drain line.

2. The floatless condensate pump control module of claim 1, wherein the microcontroller further implements the steps of

a. monitoring the water level sensor while the speed of the pump motor is increasing;

and

b. setting the speed of the pump motor at the lowest speed reached when the water subsequently falls below the intermediate level.

3. The floatless condensate pump control module of claim 1, wherein the microcontroller further implements the steps of:

a. timing a dwell time that the water stays at or above the intermediate level while the pump motor is running at the first low speed; and

b. in response to the dwell time exceeding a first predetermined threshold increasing the speed of the pump motor until the dwell time is reduced to a second predetermined threshold thereby keeping the speed of the pump motor at the lowest speed required to pump the water out of the reservoir through the drain line to the elevation of the outlet of the drain line.

4. The floatless condensate pump control module of claim 1, wherein the starting step includes applying full power to the pump motor for a short period of time to ensure that the pump motor starts prior to establishing the first low speed for the pump motor.

5. The floatless condensate pump control module of claim 1, wherein the water level sensor includes an empty capacitance sensor located at a low water level in the reservoir, a run capacitance sensor located at the intermediate water level in the reservoir, and an overflow capacitance sensor located at a near overflow water level in the reservoir, each of such capacitance sensors being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at a low water level, at an intermediate water level, or at a near overflow water level based on changes in capacitance of each capacitance sensor when each capacitor sensor is in contact with the water in the reservoir.

6. The floatless condensate pump control module of claim 1, wherein the water level sensor includes an empty capacitance sensor located at a low water level in the reservoir and a run capacitance sensor located at an intermediate water level in the reservoir, each of such capacitance sensors being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at a low water level based on a change in capacitance of the empty capacitance sensor when the empty capacitor sensor is in contact with the water in the reservoir, wherein the microcontroller determines whether the water in the reservoir is at an intermediate water level based on a change in capacitance of the run capacitance sensor when the run capacitor sensor is in contact with the water in the reservoir, and wherein the microcontroller determines whether the water in the reservoir is at a near overflow water level based on the time that the water in the reservoir is in contact with the run capacitance sensor while the pump motor is running.

7. The floatless condensate pump control module of claim 1, wherein the water level sensor includes an elongated capacitance sensor located in the reservoir with its length vertically oriented in the reservoir, the capacitance sensor being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at a low water level, an intermediate water level, or a near overflow water level based on changes in capacitance of the capacitance sensor as the water in the reservoir rises and falls along the length of the capacitance sensor.

8. The floatless condensate pump control module of claim 1, wherein the water level sensor is an ultrasonic transmitter and receiver.

9. The floatless condensate pump control module of claim 1, wherein the floatless condensate pump control module further includes a status indicator light controlled by the microcontroller to indicate visually the operating status of the condensate pump.

10. The floatless condensate pump control module of claim 1, wherein the floatless condensate pump control module further includes an infrared emitter and an infrared receiver connected to the microcontroller for transmitting and receiving data to and from the microcontroller.

11. The floatless condensate pump control module of claim 1, wherein the floatless condensate pump control module further includes an RF transceiver connected to the microcontroller for transmitting and receiving data to and from the microcontroller.

12. The floatless condensate pump control module of claim 1, wherein the floatless condensate pump control module further includes an alarm switch controlled by the microcontroller to sound an alarm when the condensate water in the reservoir reaches a near overflow condition.

13. The floatless condensate pump control module of claim 1, wherein the floatless condensate pump control module further includes an safety switch controlled by the microcontroller to shut down the HVAC system when the condensate water in the reservoir reaches a near overflow condition.

14. In a condensate pump for an HVAC system having a reservoir for collecting condensate water and a pump motor connected to an impeller pump within the reservoir for pumping the condensate water out of the reservoir through a drain line, a floatless condensate pump control module comprising:

a. a floatless water level sensor for detecting the level of water in the reservoir;

b. a variable pump motor control switch for starting, stopping, and controlling the speed of the pump motor; and

c. a microcontroller for controlling the operation of the variable pump motor control switch, in response to the detected water level, the microcontroller implementing the steps of;

i. detecting when the water in the reservoir is above a low water level;

ii. determining the time that the water has been above the low water level while the motor is not running; and

iii. if the time is greater than a predetermined threshold, starting the pump motor to pump the water out of the reservoir.

15. The floatless condensate pump control module of claim 14, wherein the starting step includes applying full power to the pump motor for a short period of time to ensure that the pump motor starts.

16. The floatless condensate pump control module of claim 14, wherein the water level sensor includes an empty capacitance sensor located at the low water level in the reservoir, a run capacitance sensor located at an intermediate water level in the reservoir, and an overflow capacitance sensor located at a near overflow water level in the reservoir, each of such capacitance sensors being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at the low water level, at the intermediate water level, or at the near overflow water level based on changes in capacitance of each capacitance sensor when each capacitor sensor is in contact with the water in the reservoir.

17. The floatless condensate pump control module of claim 14, wherein the water level sensor includes an empty capacitance sensor located at the low water level in the reservoir and a run capacitance sensor located at an intermediate water level in the reservoir, each of such capacitance sensors being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at the low water level based on a change in capacitance of the empty capacitance sensor when the empty capacitor sensor is in contact with the water in the reservoir, wherein the microcontroller determines whether the water in the reservoir is at the intermediate water level based on a change in capacitance of the run capacitance sensor when the run capacitor sensor is in contact with the water in the reservoir, and wherein the microcontroller determines whether the water in the reservoir is at a near overflow water level based on the time that the water in the reservoir is in contact with the run capacitance sensor while the pump motor is running.

18. The floatless condensate pump control module of claim 14, wherein the water level sensor includes an elongated capacitance sensor located in the reservoir with its length vertically oriented in the reservoir, the capacitance sensor being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at the low water level, an intermediate water level, or a near overflow water level based on changes in capacitance of the capacitance sensor as the water in the reservoir rises and falls along the length of the capacitance sensor.

19. The floatless condensate pump control module of claim 14, wherein the water level sensor is an ultrasonic transmitter and receiver.

20. The floatless condensate pump control module of claim 14, wherein the floatless condensate pump control module further includes a status indicator light controlled by the microcontroller to indicate visually the operating status of the condensate pump.

21. The floatless condensate pump control module of claim 14, wherein the floatless condensate pump control module further includes an infrared emitter and an infrared receiver connected to the microcontroller for transmitting and receiving data to and from the microcontroller.

22. The floatless condensate pump control module of claim 14, wherein the floatless condensate pump control module further includes an RF transceiver connected to the microcontroller for transmitting and receiving data to and from the microcontroller.

23. The floatless condensate pump control module of claim 14, wherein the floatless condensate pump control module further includes an alarm switch controlled by the microcontroller to sound an alarm when the condensate water in the reservoir reaches a near overflow condition.

24. The floatless condensate pump control module of claim 14, wherein the floatless condensate pump control module further includes an safety switch controlled by the microcontroller to shut down the HVAC system when the condensate water in the reservoir reaches a near overflow condition.

25. In a condensate pump for an HVAC system having a reservoir for collecting condensate water and a pump motor connected to an impeller pump within the reservoir for pumping the condensate water out of the reservoir through a drain line, a floatless condensate pump control module comprising:

a. a floatless water level sensor for detecting the level of water in the reservoir;

b. a variable pump motor control switch for starting, stopping, and controlling the speed of the pump motor;

c. an HVAC control switch to enable and disable the HVAC system; and

d. a microcontroller for controlling the operation of the variable pump motor control switch, in response to the detected water level, the microcontroller implementing the steps of;

i. detecting when the water in the reservoir has reached a near overflow water level;

ii. in response to the water reaching the near overflow water level, increasing the speed of the pump motor to its maximum speed;

iii. timing a first dwell time that the water stays at or above the near overflow water level;

iv. in response to the first dwell time exceeding a first predetermined threshold, rapidly changing the speed of the pump motor to create pulses of water in the drain line;

v. timing a second dwell time that the water stays at or above the near overflow water level after the pump motor begins rapidly changing speeds;

vi. in response to the second dwell time exceeding a second predetermined threshold, shutting off the HVAC system by means of the HVAC control switch.

26. The floatless condensate pump control module of claim 25, wherein the water level sensor includes an empty capacitance sensor located at a low water level in the reservoir, a run capacitance sensor located at an intermediate water level in the reservoir, and an overflow capacitance sensor located at the near overflow water level in the reservoir, each of such capacitance sensors being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at the low water level, at the intermediate water level, or at the near overflow water level based on changes in capacitance of each capacitance sensor when each capacitor sensor is in contact with the water in the reservoir.

27. The floatless condensate pump control module of claim 25, wherein the water level sensor includes an empty capacitance sensor located at a low water level in the reservoir and a run capacitance sensor located at an intermediate water level in the reservoir, each of such capacitance sensors being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at the low water level based on a change in capacitance of the empty capacitance sensor when the empty capacitor sensor is in contact with the water in the reservoir, wherein the microcontroller determines whether the water in the reservoir is at the intermediate water level based on a change in capacitance of the run capacitance sensor when the run capacitor sensor is in contact with the water in the reservoir, and wherein the microcontroller determines whether the water in the reservoir is at the near overflow water level based on the time that the water in the reservoir is in contact with the run capacitance sensor while the pump motor is running.

28. The floatless condensate pump control module of claim 25, wherein the water level sensor includes an elongated capacitance sensor located in the reservoir with its length vertically oriented in the reservoir, the capacitance sensor being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at a low water level, an intermediate water level, or the near overflow water level based on changes in capacitance of the capacitance sensor as the water in the reservoir rises and falls along the length of the capacitance sensor.

29. The floatless condensate pump control module of claim 25, wherein the water level sensor is an ultrasonic transmitter and receiver.

30. The floatless condensate pump control module of claim 25, wherein the floatless condensate pump control module further includes a status indicator light controlled by the microcontroller to indicate visually the operating status of the condensate pump.

31. The floatless condensate pump control module of claim 25, wherein the floatless condensate pump control module further includes an infrared emitter and an infrared receiver connected to the microcontroller for transmitting and receiving data to and from the microcontroller.

32. The floatless condensate pump control module of claim 25, wherein the floatless condensate pump control module further includes an RF transceiver connected to the microcontroller for transmitting and receiving data to and from the microcontroller.

33. The floatless condensate pump control module of claim 25, wherein the floatless condensate pump control module further includes an alarm switch controlled by the microcontroller to sound an alarm when the condensate water in the reservoir reaches a near overflow condition.

34. The floatless condensate pump control module of claim 25, wherein the floatless condensate pump control module further includes an safety switch controlled by the microcontroller to shut down the HVAC system when the condensate water in the reservoir reaches a near overflow condition.

35. In a condensate pump for an HVAC system having a reservoir for collecting condensate water and a pump motor connected to an impeller pump within the reservoir for pumping the condensate water out of the reservoir through a drain line, a floatless condensate pump control module comprising:

a. a floatless water level sensor for detecting the level of water in the reservoir;

b. a variable pump motor control switch for starting, stopping, and controlling the speed of the pump motor; and

c. a microcontroller for controlling the operation of the variable pump motor control switch, in response to the detected water level, the microcontroller implementing the steps of;

i. timing a cleaning dwell time;

ii. determining that the cleaning dwell time has exceed a predetermined threshold and that the water in the reservoir has reached an intermediate water level;

iii. in response to the cleaning dwell time exceeding the predetermined threshold and in response to the water being at or above the intermediate water level, starting the pump motor and rapidly changing the speed of the pump motor to create pulses of water in the drain line and to agitate the water in the reservoir.

36. The floatless condensate pump control module of claim 35, wherein the starting step includes applying full power to the pump motor for a short period of time to ensure that the pump motor starts prior to rapidly changing the speed of the pump motor.

37. The floatless condensate pump control module of claim 35, wherein the water level sensor includes an empty capacitance sensor located at a low water level in the reservoir, a run capacitance sensor located at the intermediate water level in the reservoir, and an overflow capacitance sensor located at a near overflow water level in the reservoir, each of such capacitance sensors being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at the low water level, at the intermediate water level, or at the near overflow water level based on changes in capacitance of each capacitance sensor when each capacitor sensor is in contact with the water in the reservoir.

38. The floatless condensate pump control module of claim 35, wherein the water level sensor includes an empty capacitance sensor located at a low water level in the reservoir and a run capacitance sensor located at the intermediate water level in the reservoir, each of such capacitance sensors being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at the low water level based on a change in capacitance of the empty capacitance sensor when the empty capacitor sensor is in contact with the water in the reservoir, wherein the microcontroller determines whether the water in the reservoir is at the intermediate water level based on a change in capacitance of the run capacitance sensor when the run capacitor sensor is in contact with the water in the reservoir, and wherein the microcontroller determines whether the water in the reservoir is at the near overflow water level based on the time that the water in the reservoir is in contact with the run capacitance sensor while the pump motor is running.

39. The floatless condensate pump control module of claim 35, wherein the water level sensor includes an elongated capacitance sensor located in the reservoir with its length vertically oriented in the reservoir, the capacitance sensor being connected to the microcontroller, wherein the microcontroller determines whether the water in the reservoir is at a low water level, the intermediate water level, or a near overflow water level based on changes in capacitance of the capacitance sensor as the water in the reservoir rises and falls along the length of the capacitance sensor.

40. The floatless condensate pump control module of claim 35, wherein the water level sensor is an ultrasonic transmitter and receiver.

41. The floatless condensate pump control module of claim 35, wherein the floatless condensate pump control module further includes a status indicator light controlled by the microcontroller to indicate visually the operating status of the condensate pump.

42. The floatless condensate pump control module of claim 35, wherein the floatless condensate pump control module further includes an infrared emitter and an infrared receiver connected to the microcontroller for transmitting and receiving data to and from the microcontroller.

43. The floatless condensate pump control module of claim 35, wherein the floatless condensate pump control module further includes an RF transceiver connected to the microcontroller for transmitting and receiving data to and from the microcontroller.

44. The floatless condensate pump control module of claim 35, wherein the floatless condensate pump control module further includes an alarm switch controlled by the microcontroller to sound an alarm when the condensate water in the reservoir reaches a near overflow condition.

45. The floatless condensate pump control module of claim 35, wherein the floatless condensate pump control module further includes an safety switch controlled by the microcontroller to shut down the HVAC system when the condensate water in the reservoir reaches a near overflow condition.