Abstract: A three-dimensional filter includes a filter frame having a three-dimensional skeletal structure with a filter media connected to the skeletal structure. The filters are nestable. The skeletal structure may be trimmed and provided with walls to create standard sized filters. Methods for making the three-dimensional filter include injection molding of the skeletal structure onto the filter media, injection molding the filter media and the filter frame together in a single molding process, thermoforming a molded or extruded skeletal structure and the filter media, and needle punching a molded or extruded skeletal structure to create filter media within the skeletal structure.

Abstract: A liquid handling system having a tank with a centrifugal pump for pumping the liquid out of the tank is disclosed. The centrifugal pump is located beneath tank and has a coaxial inlet-outlet. Capacitive sensors are used to detect the level of liquid in the tank, and control circuits are connected to the capacitive sensors and control the operation of the pump.

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.

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 controller. The floatless pump controller 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 controller may employ an ultrasonic transducer or capacitance sensors to detect the level of condensate water in the reservoir.

Abstract: A three-dimensional filter includes a filter frame having a three-dimensional skeletal structure with a filter media connected to the skeletal structure. The filters are nestable. The skeletal structure may be trimmed and provided with walls to create standard sized filters. Methods for making the three-dimensional filter include injection molding of the skeletal structure onto the filter media, injection molding the filter media and the filter frame together in a single molding process, thermoforming a molded or extruded skeletal structure and the filter media, and needle punching a molded or extruded skeletal structure to create filter media within the skeletal structure.

Abstract: A flushing solvent for flushing an HVAC-R system is a mixture of hydrofluoroether, acetone, t-Butyl acetate, and trans 1,2 Dichloroethylene.

Abstract: A three-dimensional filter includes a filter frame having a three-dimensional skeletal structure with a filter media connected to the skeletal structure. The filters are nestable. The skeletal structure may be trimmed and provided with walls to create standard sized filters. Methods for making the three-dimensional filter include injection molding of the skeletal structure onto the filter media, injection molding the filter media and the filter frame together in a single molding process, thermoforming a molded or extruded skeletal structure and the filter media, and needle punching a molded or extruded skeletal structure to create filter media within the skeletal structure.

Abstract: A condensate pump for an HVAC system includes a reservoir, a solenoid pump assembly with a solenoid pump, and a solenoid pump electronic control module for limiting the amount of energy delivered to the solenoid pump during one half cycle from an AC current source. The solenoid pump is mounted in the solenoid pump assembly by means of shock absorbing material, and the solenoid pump assembly is mounted on a support member with shock absorbing material interposed between the solenoid pump assembly and the support member.

Abstract: A service gauge for determining refrigerant pressure and the saturated vapor equivalent temperature, or other parameters, for a refrigerant in an HVAC system. In one embodiment, the service gauge employs a bourdon tube with at least one attached strain gauge to sense the refrigerant pressure and produce an electronic pressure signal. In another embodiment, a magnet and rotary position sensor produces an electronic signal proportional to the refrigerant pressure. The electronic pressure signal from the output of the strain gauge or the rotary position sensor is connected to a microprocessor, which calculates and displays the refrigerant pressure, the saturated vapor equivalent temperature for a variety of refrigerants, produces instantaneous and time lapsed representations of those parameters, and other parameters of the refrigerant.