Abstract: A device and method are provided to allow replacement of costlier motors with a retrofittable control board and a lower cost motors operating a several speeds to provide variable (but not continuously variable) blower airflow. The control signals normally used to command the motor being replaced are only used to detect the need to activate the blower motor; once detected, the control board activates the replacement blower motor by energizing a blower motor speed tap with the evaporator blower initially set to a high speed. Then the blower speed is lowered if a predetermined negligibly small, acceptable change in evaporator temperature has occurred. Given the number of speed taps on the replacement blower motor, the evaporator blower speed is continued to be reduced from the initially set high speed as long as there is only an acceptably small change in the measured evaporator temperature.

Abstract: A system and method are provided to allow the replacement of a costly electrically commutated blower or fan motor with a less efficient motor such as a permanent split capacitor motor operating at a predetermined speed, without regard to the specific electrically commutated motor command signals or programming being used by the original equipment manufacturer. A retrofittable control board is employed to activate the replacement motor by energizing the replacement blower motor when an electrically commutated blower motor command signal is observed on any one of the signal lines which are continuously monitored simultaneously.

Abstract: A method and device for improving moisture removal capacity of a vapor compression system is disclosed. The vapor compression system is started up with the evaporator blower initially set to a high speed. A relative humidity in a return air stream is measured with the evaporator blower operating at the high speed. If the measured humidity is above the predetermined high relative humidity value, the evaporator blower speed is reduced from the initially set high speed to the lowest possible speed. The device is a control board connected with the blower and uses a predetermined change in measured relative humidity to control the blower motor speed.

Abstract: A device and method are provided to improve performance of a vapor compression system using a retrofittable control board to start up the vapor compression system with the evaporator blower initially set to a high speed. A baseline evaporator operating temperature with the evaporator blower operating at the high speed is recorded, and then the device detects if a predetermined acceptable change in evaporator temperature has occurred. The evaporator blower speed is reduced from the initially set high speed as long as there is only a negligible change in the measured evaporator temperature and therefore a negligible difference in the compressor's power consumption so as to obtain a net increase in the Coefficient of Performance.

Abstract: A method and apparatus for detecting the presence and concentration of organic and inorganic acids by their infrared absorption characteristics in a refrigeration unit while running. Acids of interest, such of those formed upon decomposition of refrigerant or refrigerant oil, are volatilized and subjected to infrared radiation. Optical filtering is used to limit the infrared radiation to relevant wavelengths. Organic acids are detected by the absorbance of energy between 4-6 microns while inorganic acids are detected by the absorbance of energy between 2-4 microns.