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: A method of controlling an expansion valve including the steps of: measuring a primary system condition; determining an error in the primary system condition; measuring a secondary system condition; determining an error in the secondary system condition; and modulating the expansion valve based upon the larger of the first or second error.

Abstract: A method of measurement. The method comprises the steps of (a) measuring a value, (b) forwarding the measured value as an analog signal, (c) dithering the analog signal to improve resolution and (d) converting the analog signal to a digital signal.

Abstract: The existence of inverted start conditions in a refrigeration chiller is accurately identified by sensing the liquid level in the chiller evaporator. That liquid level is indicative of the location of the chiller's refrigerant charge at start-up. If the sensed liquid level is below a predetermined level, an inverted start condition is verified to exist. Failed starts and chiller system shutdowns are reduced or avoided as compared to systems in which less reliable indicators are used to identify the existence of inverted start conditions.

Abstract: An upper housing shell of a hermetically sealed refrigeration compressor has a central asymmetrical section interposed between a lower cylindrical section and an upper spherical section. The shape of the central section is such that opposite points define a line that is perpendicular to the surface at one point, but is not perpendicular to the surface at the opposite point.

Abstract: A refrigeration apparatus contains an oil sump having an interior portion. A housing is located, at least in part, within the oil sump interior. The housing has at least one inlet and at least one outlet. The inlet allows a vent gas stream to enter the housing and the outlet allows a vent gas stream to exit the housing. The inlet may be an aperture extending circumferentially around the housing about one-third to one-half of the housing's circumference. Additionally, the inlet should be above the surface level of any oil pool in the sump. A coalescing demister filter is located within the housing between the inlet and the outlet. The housing may include a wall for sheltering the filter from agitated areas of the gearbox. The filter is configured to remove substantially all of the oil from the vent gas stream. The filter may also have an outlet end which is sealed from the oil sump. The filter may also be pleated and enhances oil coalescence.

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 multi-ported frame in conjunction with separate suction gas supply and lubricant return passages cooperatively defined by the compressor shell and the stator of the motor which drives the compressor.

Abstract: The position of a screw compressor slide valve in a refrigeration system is controlled using compressor discharge gas sourced from a location where the gas is relatively oil-free and has undergone little or no pressure drop subsequent to its discharge from the compressor's working chamber.

Abstract: A condensate drain pan arrangement with a positive slope. The drain pan arrangement comprises a housing including a first wall with a first aperture, a second wall with a second aperture where the first and second walls are spaced; a coil located in the space in the housing and between the first and second walls; and a drain pan having a condensate receiving portion within the housing and located under the coil. The drain pan includes a first end cap with a drainage attachment proximal the first aperture and positively engaged to the first wall, and a second end cap proximal the second aperture. The second end cap includes an engagement portion and a bottom portion. The drain pan arrangement includes an access plate including a lifting portion operably engaged to the bottom portion and raising same predetermined amount, and a securing portion operably engaged with the engagement portion to prevent movement of the second end cap, the second end cap is fixed with relation to the second wall.

Abstract: A heat exchanger for an air conditioner outdoor unit includes tubing of the microchannel type which is internally partitioned into separate, parallel refrigerant flow passages and a wrapping of heat conductive flexible heat transfer material, commonly known as spine fin. The heat exchanger provides for greater heat transfer and a more compact package. Further, such heat exchangers allow for a reduced refrigerant charge in the air conditioning unit in which they are used.

Abstract: A method of controlling compressor minimum capacity. The method comprises the steps of: measuring a first condition; comparing the first condition to a first setpoint to determine a first conditioned error; modulating compressor capacity relative to the first condition error; measuring a second condition; comparing the second condition to a second setpoint to determine a second condition error; and modulating compressor capacity relative to the second condition error if the magnitude of the second conditioned error is greater than the magnitude of the first conditioned error.

Abstract: An air conditioning unit comprising: a housing having a first half and a second half; the first half of the housing containing an indoor heat exchange coil and a blower moving air through said coil from at least a housing inlet to a housing outlet. The blower discharges into a diffuser duct having a diffuser section with a first segment and a second segment where the first and second segments have first and second respective and differing angles of diffusion.

Abstract: An air conditioning system. The system comprises an indoor section and an outdoor section arranged in side-by-side arrangement. The indoor section includes an indoor tangential fan having an axis aligned in a first direction, an indoor heat exchange coil, and a supply air aperture which longitudinally extends in the first direction and avoids line of sight noise transmission from the indoor fan. The system includes an axis commonly supporting and operably coupling the indoor fan and the motor, and a scroll housing within the indoor section and arranged about the indoor tangential fan. The indoor tangential fan, motor and axis are assembled to form a first module, the scroll housing forms a second module and the first module is independently removable from the second module without the necessity of disengaging any connection between the first and second modules. The system includes a fan support bracket supporting a first end of the axis, and the motor supporting a second end of the axis.

Abstract: A method of operating an HVAC system having an HVAC control and a humidity limiting control. The method comprises the steps of: determining a relative humidity limit for a space; monitoring relative humidity in the space; comparing the relative humidity to the relative humidity limit; operating the conventional HVAC control if the space humidity does not exceed the humidity limit; and integrating the HVAC control and dehumidification controls if the space conditions require humidity limiting action.

Abstract: A method and a device for continuously forming a heat exchanger that has a helically wound fin tube coil formed by a plurality of wraps. The device 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 protection system for a compressor. The system comprises a compressor having a discharge and including at least one rotor and at least one bearing; a lubrication system including at least one oil recovery device for recovering oil from the compressor, and further including bearing conduit connecting the oil recovery device to the compressor bearing and including rotor conduit for connecting the oil recovery device to the compressor rotors; and an oil protection system. The oil protection system includes a compressor discharge temperature sensor located in the discharge for sensing the temperature of a lubricant/refrigerant mixture discharged by the compressor, a differential pressure sensor located in the bearing conduit for measuring a differential pressure in the bearing conduit, and an oil detector located in the rotor conduit for detecting the presence of oil in the rotor conduit.

Abstract: An apparatus and method for soft-starting a three-phase motor for connection to a three-phase power source for driving a three-phase motor. Soft-start provides a way to reduce the amount of starting torque and current during starting conditions. First, second, and third conductors are connected between a three-phase power source and a three-phase motor. A power contactor interrupts and provides current along the three conductors. A phase-shifting element for shifting the phase of the power signal normally outputted from the first conductor to match the phase of the power signal normally outputted from the third conductor is connected between the first and third conductors. A switching apparatus having first and second switch elements is connected between the phase-shifting element and the third conductor. When the first switch element is closed, current flows from the first conductor to the motor via the phase-shifting element.

Abstract: A fan assembly. The fan assembly comprises: a fan having an axis and an outer periphery; a housing about the fan; and a cutoff separating fan inflow from fan outflow. The cutoff is preferably arranged parallel to the axis and is proximal to the outer periphery. The cutoff includes first and second layers. The first layer provides structural support and has a plurality of apertures therethrough. The second layer is formed of an acoustically insulating material.

Abstract: A single motor drives both oil and refrigerant pumps in a refrigeration chiller, the motor and oil pump being disposed in the chiller's oil supply tank and the refrigerant pump being disposed exterior thereof. The refrigerant pump pumps liquid refrigerant to the chiller's compressor section so as to cool the motor by which the compressor is driven while the oil pump pumps oil to chiller locations that require lubrication when the chiller is in operation.

Abstract: An improved distribution system for an evaporator. The system comprises an evaporator having a plurality of heat exchange flow paths; and an evaporator distributor operably connecting the plurality of flow paths to an evaporator inlet. The system includes an impingement device having an outlet operably connected to the evaporator inlet and having at least a pair of fluid inlets arranged so that fluid entering through either of the fluid inlets directly impinges upon fluid entering the other fluid inlet thereby providing a churned up fluid to the impingement device outlet. Additionally, the system includes an expansion device having an inlet and an outlet; and a separator having a separator inlet connected to the expansion valve outlet and having at least a pair of outlets. The separator is arranged to divide fluid from the expansion device into several streams and direct those streams to its outlets.