Evaporator for air-source heat pumps

Abstract

Apparatus for evaporating water condensate produced by an air-source heat pump, such as an air conditioner, the apparatus having a housing adapted, in use, to be positioned below the condensate drain of a heat pump, a condensate container within or forming part of the housing for collecting condensate, the container having a deep end and a shallow end, means for detecting when a minimum level of water is in the container and for sending signals indicative thereof to an electronic control unit (ECU), and electric heater means for heating, either directly or indirectly, the water to cause evaporation thereof in response to command signals from the ECU. In a first aspect the housing and container has a lid with an opening to receive liquid condensate remote from the heat pump and in a second aspect the apparatus is adapted to be fitted directly to the underside of a pre-installed heat pump.

1 ) Apparatus for evaporating water condensate produced by an air-source heat pump, the apparatus having a housing adapted, in use, to be positioned below the condensate drain of a heat pump, a condensate container within or forming part of the housing for collecting condensate, the container having a deep end and a shallow end, means for detecting when a minimum level of water is in the container and for sending signals indicative thereof to an electronic control unit (ECU), and electric heater means for heating, either directly or indirectly, the water to cause evaporation thereof in response to command signals from the ECU. 
     
     
         2 ) Apparatus according to  claim 1  wherein the container includes a lid, an inlet for receiving therethrough liquid condensate from the heat pump, and a vent for expelling evaporated condensate from the container. 
     
     
         3 ) Apparatus according to  claim 1  wherein the container has generally upright sidewalls, a lid and a generally flat base disposed at an angle to the horizontal to thereby define a cross-section of generally frusto-triangular shape. 
     
     
         4 ) Apparatus according to  claim 3  wherein the angle of the base is between about 10° and 15° and preferably about 12° from the horizontal. 
     
     
         5 ) Apparatus according to  claim 1  wherein the heater means comprises an array of electric strip heaters arranged in parallel relationship on the underside of the container whereby to permit the ECU to selectively activate and manage each heater. 
     
     
         6 ) Apparatus according to  claim 5  wherein the electric strip heaters are silicone strip heaters. 
     
     
         7 ) Apparatus according to  claim 5  wherein each strip heater includes means for sensing its own temperature and conveying signals indicative thereof to the ECU. 
     
     
         8 ) Apparatus according to  claim 7  wherein the temperature sensing means comprises a negative temperature coefficient thermistor (NTC). 
     
     
         9 ) Apparatus according to  claim 5  wherein the ECU is operable to independently activate each strip heater whereby to maintain a generally consistent temperature profile at the base of the container. 
     
     
         10 ) Apparatus according to  claim 9  wherein the consistent temperature profile of the base of the container is obtained via command signals from the ECU providing independently pulsed outputs to each strip heater. 
     
     
         11 ) Apparatus according to  claim 1  wherein the means for detecting when a sufficient level of condensate is in the container comprises a pair of electrodes disposed within the container, the electrodes being operatively connected to the ECU to thereby form an open circuit closable by the presence of condensate water whereby to activate the heater means and commence condensate evaporation. 
     
     
         12 ) Apparatus for evaporating water condensate produced by an air-source heat pump of the type having a generally sealed base with a drain for removing liquid condensate, the apparatus having a housing adapted to be positioned below the condensate drain of the heat pump, a condensate container within or forming part of the housing for collecting condensate from the heat pump, the container having a deep end and a shallow end, means for detecting when a minimum level of water is in the container and for sending signals indicative thereof to an electronic control unit (ECU), and electric heater means for heating, either directly or indirectly, the water to cause evaporation thereof in response to command signals from the ECU.