Abstract: A method of optimizing the design of a chiller involves placing more emphasis on the chiller's performance at part load than at full load and rating the chiller accordingly. In some embodiments, compressor speed and impeller diameter are chosen to optimize the chiller's performance at part load. With the chosen impeller diameter, operation at full load is then achieved by increasing compressor speed, opening inlet guide vanes, and perhaps sacrificing some efficiency. If necessary, an inverter over speeds the compressor by driving it at a speed beyond that which the compressor would normally run if it were driven at the nominal line frequency of the electrical power feeding the inverter.

Abstract: An enhanced motor cooling and lubrication system for a liquid chiller includes a liquid refrigerant cooled compressor drive motor, wherein the refrigerant used to cool the drive motor is returned to the chiller's condenser, and apparatus to better facilitate the return of oil carried to the compressor entrained in the suction gas flow stream back to the chiller's oil supply tank.

Abstract: An air inlet and damper arrangement. The arrangement comprises a system housing with an external wall having a fresh air inlet; and an inlet air enclosure located within the system housing adjacent the external wall and arranged about the air inlet. The enclosure has an aperture connecting the interior of the enclosure with the interior of the system housing; and a damper sized to cover the aperture and pivotable within the small enclosure between a position covering the aperture and a position uncovering the aperture.

Abstract: A device for monitoring and modulating the admission of fresh air into a building. The device comprises a housing; a sensor associated with the housing and operable to measure airflow through the housing; and a damper including at least two damper blades. Each damper blade includes a shaft rotatably attached to the housing at least at a first shaft end. The shaft is located on the surface of the damper blade so as to divide the surface into first and second substantially equal areas.

Abstract: A device for monitoring and modulating the admission of fresh air into a building. The device comprises a housing; a sensor associated with the housing and operable to measure airflow through the housing; and a damper including at least two damper blades. Each damper blade includes a shaft rotatably attached to the housing at least at a first shaft end. The shaft is located on the surface of the damper blade so as to divide the surface into first and second substantially equal areas.

Abstract: A method of minimizing energy use in a chiller and cooling tower system is disclosed. The method comprises the steps of: determining a measure of chiller efficiency; determining a measure of cooling tower efficiency; determining a measure of the transfer rate of heat energy between the cooling tower and the chiller; calculating a near optimal water temperature as a function of the chiller work efficiency, the cooling tower efficiency and the transfer rate; and operating the cooling tower to provide a conditioned fluid at the temperatures to produce near optimal energy consumption.

Abstract: A method of controlling a multiplicity of condenser fans in a refrigeration system comprising the steps of: calculating a first difference in state between a high pressure side and a low pressure side of the refrigeration system; determining an optimum state for the refrigeration system; determining a second difference in state between the first difference and the optimum difference; and controlling the multiplicity of condenser fans if the second difference exceeds a predetermined value.