Abstract: A system includes a load module, a comparison module and a control module. The load module is configured to determine a current load of a compressor. The comparison module is configured to compare the current load to a previous load of the compressor to generate a comparison signal based on the comparison. The control module is configured to generate (i) a first control signal based on a superheat value of the compressor, and (ii) a second control signal based on the current load and the previous load. The control module is configured to, based on the comparison signal, control a position of an expansion valve according to either the first control signal or the second control signal.

Abstract: A system includes an error module configured to integrate a difference between a superheat signal and a superheat setpoint to generate an error signal, wherein the superheat signal indicates suction superheat values of a compressor. A comparison module is configured to compare the error signal to a first predetermined threshold to generate a first comparison signal based on the comparison. A zero-crossing module is configured to compare a first count value to a second predetermined threshold to generate a second comparison signal. The first count value is generated based on at least one comparison between the superheat signal and the superheat setpoint. A setpoint module is configured to adjust the superheat setpoint based on the first comparison signal and the second comparison signal.

Abstract: A cooling system has a cabinet and a plurality of separate cooling stages including an upstream cooling stage and a downstream cooling stage. At least the upstream cooling state is a variable capacity cooling stage. Each cooling stage has a cooling circuit. Evaporators of the cooling circuits are arranged in the cabinet so that air passes over them in serial fashion. A controller when a Call for Cooling first reaches a point where cooling is needed, operating the upstream cooling circuit to provide cooling and not the downstream cooling circuit. When the Call for Cooling has increased to a second point, the controller additionally operates the downstream cooling circuit to provide cooling. The cooling capacity at which the upstream cooling circuit is being operated is less than its full capacity when the Call for Cooling reaches the second point.

Abstract: A cooling system has a plurality of separate cooling stages including an upstream cooling stage having an upstream cooling circuit and a downstream cooling stage including a downstream cooling circuit, which are each a direct expansion cooling circuit including a tandem compressor. Each tandem compressor includes a fixed capacity compressor and a variable capacity compressor. A controller controls the fixed capacity compressor and variable capacity compressor of each tandem compressor based on a Call for Cooling, which of a plurality of ranges the Call for Cooling falls within, and whether the Call for Cooling is ramping up or ramping down.

Abstract: A conditioning unit can allow the blower to be easily translated from a first operable position in the conditioning unit to a second operable position external to the conditioning unit. The translation of the blower does not require the disconnection of the blower and, accordingly, does not require that the blower be disconnected and reconnected to the control system. Such capability can facilitate the installation of the conditioning unit into a variety of applications and allows the purchaser to customize the blower location based on the desired performance. The ability to customize the installation of the conditioning unit without requiring disconnection and reconnection of the blower can reduce the cost and expense associated with the installation into differing applications.

Abstract: A conditioning unit can allow the blower to be easily translated from a first operable position in the conditioning unit to a second operable position external to the conditioning unit. The translation of the blower does not require the disconnection of the blower and, accordingly, does not require that the blower be disconnected and reconnected to the control system. Such capability can facilitate the installation of the conditioning unit into a variety of applications and allows the purchaser to customize the blower location based on the desired performance. The ability to customize the installation of the conditioning unit without requiring disconnection and reconnection of the blower can reduce the cost and expense associated with the installation into differing applications.

Abstract: A vapor compression cooling system having a control unit adapted to receive working fluid pressure or temperature, environment temperature or relative humidity, compressor digital output, or other cooling system information to control a condenser cooling fluid control valve to minimize flow changes through the valve.

Abstract: A vapor compression cooling system having a control unit adapted to receive working fluid pressure or temperature information to control a condenser cooling fluid control valve to minimize flow changes through the valve.

Abstract: A method and apparatus is disclosed to relieve liquid pressure from a receiver to a condenser in a cooling system that operates under a variety of ambient temperature conditions. To relieve excess pressure in the receiver and to prevent the venting of refrigerant through a relief valve, a pressure-balancing system is connected between the condenser and the receiver of the cooling system. In one embodiment, the pressure-balancing system includes a check valve and a pressure-balancing valve. The pressure-balancing valve bypasses the check valve. The check valve permits the flow of refrigerant in one direction from the condenser to the receiver. The pressure-balancing valve permits the flow of refrigerant in an opposite direction from the receiver to the condenser in order to maintain the pressure in the receiver below a maximum pressure level. The pressure-balancing valve may be installed on a bypass line parallel to the check valve.