Abstract: A refrigerant distributor for use in a shell and tube evaporator has a decreasing cross-sectional area which uniformly distributes refrigerant to the tube bundle within the evaporator shell and operates with a small distributor to evaporator pressure drop.

Abstract: The position of a slide valve in a screw compressor in a refrigeration system is controlled using a gaseous medium sourced from two or more sources of such fluid, both of which are in open flow communication with the slide valve actuating piston when the slide valve load solenoid is open. Preferred gas sources are a closed compression pocket in the working chamber of the compressor and the discharge passage downstream of the compressor's working chamber. Gas at sufficiently high pressure is available whenever the compressor is operating to ensure that the compressor will load under all conditions within the compressor's operating envelope.

Abstract: A curb for a rooftop air conditioning unit. The curb comprises: a frame having side walls and end walls arranged in a generally rectangular shape, and a generally planar portion overlaying a portion of the frame. The planar portion includes a first layer providing structural support, a second layer providing a sound barrier, and a third layer provides a heat energy barrier.

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 method of controlling fans in a rooftop air conditioning unit. The method comprises the steps of: determining a measure of compressor operating capacity; calculating an indoor fan speed as a function of that capacity; maintaining a fixed relationship between the indoor fan speed and an outdoor fan speed; and controlling the indoor fan in accordance with the calculated indoor fan speed.

Abstract: A method of controlling an expansion valve in a refrigeration system. The method comprises the steps of controlling the modulation of the expansion valve based upon a first feedback control criteria; and controlling the modulation of the expansion valve based upon a second feed forward control criteria.

Abstract: A serial heat exchanger. The heat exchanger comprises a serial passage extending from an inlet to an outlet and a plurality of vapor liquid separators extracting vapor from the passage.

Abstract: A drain spout that is easy to remove for cleaning and for accessing components behind or proximal to the drain pan. Instead of directly connecting the drain hose to the drain pan outlet spout, the drain hose connects to a drain funnel attached to or formed as a part of the shelf supporting the drain pan. The drain pan itself sits on the shelf and the outlet spout of the drain pan fits within the shelf funnel without a positive connection. The drain pan can be lifted out without disengaging the drain hose.

Abstract: A fluid level sensor. The sensor comprises a housing; a chamber enclosed by the housing; a liquid port in a lower area of the housing operable to connect the chamber to a lower, liquid containing area of a heat exchanger; and a gas port located in an upper area of the housing and operable to connect the chamber to an upper, vapor containing area of a heat exchanger. The sensor includes first and second apertures in the housing; and cooling conduit passing through the chamber and through the first and second apertures and operable to cool the chamber. There is at least one sensor located in the chamber and adapted to sense a temperature of fluid in the chamber.

Abstract: The flow, use, interaction and separation of lubricant and gas flowing through the suction pressure portion of a low-side refrigeration scroll compressor is managed by the use of a drive motor mounting sleeve and a multi-ported frame. The mounting sleeve and frame provide for the direction of oil to surfaces within the low side of the compressor shell which require lubrication as well as the conduct of suction gas to the scroll compression mechanism in a manner which cools the compressor drive motor yet which maintains the respective flows of oil and suction gas sufficiently separate to ensure that excessive amounts of oil are not conducted out of the compressor in the gas which is compressed thereby. Lubrication is enhanced by the use of a vent passage which opens into a relatively lower pressure region within the suction pressure portion of the compressor shell.

Abstract: An efficiency matching device and method. The efficiency matching device is utilized in combination with a centrifugal fan adapted to deliver an air mass flow through an air delivery system. The fan has a housing that defines an inlet port and an exit port. The fan additionally has an impeller disposed within the housing. The impeller draws air into the inlet port, accelerates the air, and discharges the air through the exit port. The efficiency matching device is shiftably carried within the exit port for selectively varying the area of the exit port such that the efficiency of the centrifugal fan can be varied to match the output efficiency of the fan to the desired air mass flow through the air delivery system.

Abstract: A refrigeration system employing a screw compressor and a falling film evaporator makes use of high-side pressure to drive lubricant, which escapes the compressor and collects as a lubricant-rich mixture of lubricant and refrigerant in the system evaporator, back to the compressor. The mixture is cyclically exposed to high-side pressure for a period of time which (i) varies in accordance with the difference between a sensed condenser-related pressure and a sensed evaporator-related pressure and (ii) is calculated to maintain a predetermined oil concentration in the lubricant-rich mixture in the evaporator so as to minimize the parasitic losses to system efficiency associated with the oil return process.

Abstract: A method of operating a heat pump or air conditioner system is provided. The air conditioner comprises a compressor, a condenser, an expansion device, a cooling coil and an air mover (blower). According to the preferred embodiment, the air mover (blower) is activated at a time after the compressor has been activated to pre-cool the cooling coil and allow for more efficient and effective moisture removal. Also, deactivation of the air handler is delayed for some time after the compressor is deactivated to allow for utilization for the residual cooling ability of the cooling coil due to the presence of cold refrigerant in the cooling coil when the compressor is deactivated.

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 continuously forming a heat exchanger that has a helically wound fin tube coil formed by a plurality of wraps includes a rotationally driven mandrel with a central axis and a plurality of forming corners equiangularly disposed about and displaced from the central axis. The rotation of the mandrel is about the central axis in order to wind the fin tube coils onto the mandrel. A forming block is operably rotationally coupled to the mandrel and rotates with the mandrel. The forming block is also slideably engaged with the mandrel for axial translation a selected distance with respect to the mandrel. The forming block guides the winding of the fin tub coils onto the mandrel. An actuator is operably coupled to the forming block and causes the axial translation of the forming block.

Abstract: A method of operating a pre-mix power burner assembly. The method comprises the steps of: using a fan to supply and control combustion; mixing fuel gas and primary air together; introducing the mixture into secondary air in a combustion zone; and relieving pressure on the exterior of the fan near the fan shaft to the interior of the fan.

Abstract: A high side co-rotational scroll compressor has lubricant sumps in both the discharge and suction pressure portions of its hermetic shell as well as a pressure biasing arrangement by which the scroll members are urged together in operation to minimize internal leakage. Lubrication of the bearing in which the driven scroll member rotates as well as to the bearing in which the idler scroll member rotates, both of which are located in the suction pressure portion of the shell, is provided for. Additionally, embodiments are taught by which the interface between the tips of the wraps of each scroll member and the end plate of the opposing scroll member are lubricated and by which the seal in the axial pressure biasing arrangement is lubricated and/or shielded from debris having the potential to damage it.

Abstract: A condensate trap assembly. The assembly comprises a housing having first and second condensate inlets where the first condensate inlet is sized to pass more condensate than the second condensate inlet. The housing has an ambient air inlet providing access to an ambient air chamber within the housing, a first condensate chamber open to the first condensate inlet, and a second condensate chamber open to the second condensate inlet. The first condensate chamber, the second condensate chamber, and the ambient air chamber are open to each other and the first condensate chamber includes airflow restrictors to retard the volume of airflow through the first chamber.

Abstract: Oil management apparatus for a refrigeration chiller includes a housing mounted to the head wall of an oil supply tank. The housing defines a series of ports and internal flow passages in communication with a valve cavity. A valve spindle disposed in the cavity is configured and positionable such that a plurality of oil flow passages within the chiller are capable of being setup in order to accommodate various chiller lubrication needs including those as they relate to both chiller operation and maintenance. The combination of an integral housing and single valve eliminates a large number of individual valves and the need to connect those valves and various chiller lubrication components, such as an oil filter and oil pressure regulator, with individual sections of difficult to fabricate piping. As a result, the likelihood of error in the setup of a chiller lubrication system is significantly reduced.

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.