Abstract: A method for determining airflow through an air cooling and dehumidifying coil by measuring the condensate rate and the moist air conditions entering and leaving the coil. The mass air flow, the volume air flow and the cooling capacity are then calculated from data exhibited on a psychrometric chart or by calculating the same result from basic principles.

Abstract: The means and method of pitching a refrigeration evaporator toward its drain outlet which includes a top plate of variable thickness. The evaporator is secured to the top plate. When the top plate is secured against the horizontal ceiling, the evaporator is caused to pitch, so that condensate leaving the coil and entering the drain pan flows directly to the drain fitting which is positioned under the portion of the top plate having the greatest thickness.

Abstract: A compressor having an oil sump, an external oil reservoir, a conduit connecting the bottom of the oil reservoir to the compressor sump, a pump in the conduit for pumping excess oil from the reservoir to the compressor sump, and an overspill from the compressor sump back to the oil reservoir and a high side or a low side oil separator for removing oil from the refrigerant flow stream and returning it to the reservoir.

Abstract: A drain assembly including a drain pipe and a heater oriented to heat the drain pipe, in combination with a defrosting type refrigeration evaporator intended for use within an enclosure whose temperature is maintained lower than the freezing point of water. The drain pipe has a discontinuity positioned in an upper portion so that defrost meltage traversing the drain tube in the ordinary course will not leak out of the pipe through the discontinuity, but that meltage backing up in the drain pipe because the drain pipe has been plugged by ice or dirt, will flow out of the discontinuity onto the freezer floor rather than backing up further into the drain pan, and the discontinuity will be maintained free of ice because it is heat transfer relation to the heater.

Abstract: An air cooling evaporator for use in refrigeration systems under conditions where frost is deposited on the cooling surfaces having a drain pan positioned under the cooling surface and a water distributing pan positioned over the cooling surface. The water distributing pan has as a distribution device holes positioned in the bottom of the pan, with the holes so positioned or sized that more water is distributed to the portions of the coil.

Abstract: Segmented doors for closing a wide opening in an enclosure where the upper door is hinged to the top of the opening, the lower door is hinged to the bottom of the upper door and a wire bail is provided for the purpose of locking the lower door into a V-like or triangular relationship with the upper door. This V-like structure, composed of the locked-together upper and lower doors, can then be rotated upward to a stable triangular or inverted V-like position atop the roof or top panel of the cabinet.

Abstract: A distributor for volatile refrigerant having a single inlet and many outlets and designed to distribute refrigerant substantially uniformly to each outlet, has its outlets manifolded together in groups to provide equal refrigerant distribution to a few relatively large loads or unequal distribution to a few relatively large loads according to a predetermined ratio, the ratio of the refrigerant distribution to the various loads being predetermined by the ratios of the numbers of outlets that are selected to serve those loads.

Abstract: A cooling unit for refrigeration systems having a substantially vertically disposed air cooling element, utilizing either a volatile or a non-volatile refrigerant, upon which element frost accumulates during the course of the refrigeration process. The element includes heaters to periodically warm the element to a temperature above 32.degree. F. to thaw the frost. These heaters have their heating capacity adjusted so that more heat is applied at the bottom portion of the frost-collecting air cooling element and less heat is supplied to the upper portion.

Abstract: A refrigeration system having compressor and condenser adapted for operation in ambients above approximately 45.degree. F (7.degree. C) and including a frosting evaporator. The evaporator is defrosted by hot gas which flows through the compressor discharge, the condenser, the receiver, the liquid line and a valve-controlled hot gas branch connected between the liquid line and the hot gas inlet of the evaporator. During defrost, a control stops the evaporator and condenser fan motor and opens the valve in the hot gas branch conduit. At defrost's end, the control causes the evaporator and condenser fan motor to operate and the hot gas valve to close so that liquid refrigerant flows from the condenser outlet through the receiver and liquid line to the expansion device which feeds the evaporator for refrigeration in the normal course.

Abstract: A compression type refrigeration system including at least one frosting evaporator positioned to refrigerate air. The evaporator has a liquid refrigerant inlet to which is connected an expansion valve. The evaporator also has a hot gas inlet; a liquid line supplies liquid to the expansion valve; a branch in the liquid line controlled by a solenoid valve connects to the hot gas inlet. The condensing unit, which includes compressor, condenser, receiver and re-evaporator, are valve-controlled so that during refrigeration, discharge gas from the compressor flows through the condenser, receiver, liquid line and expansion valve seriatim, but during defrost, gas from the compressor bypasses the condenser and flows instead from the compressor through the receiver, liquid line and hot gas inlet of the evaporator seriatim.

Abstract: A refrigerant flooding type capacity control for air cooled condensers used in compression type mechanical refrigeration systems where the liquid receiver is located in a bypass around the condenser so that the controlled heating, which is applied to the liquid refrigerant in the receiver to create the flooding effect, does not cause a warming of the cold liquid refrigerant leaving the condenser.

Abstract: A pressure switch for use in refrigeration systems which includes a restrictor to minimize the effect of compressor pulsations on the pressure sensing element and a heater positioned to warm the interior of the switch housing and to maintain the fluidity of refrigeration oil traversing the restrictor under conditions when the switch is exposed to low ambient temperatures.

Abstract: A refrigeration system which has two condensers located in different environments and intended for use alternately, a valve arrangement for determining which of the two condensers is to be operative for rejecting heat and which is to be inoperative, which includes control valves in the outlet conduit of each of the condensers arranged so that when one is open, the other is closed, and vice versa.

Abstract: A defrost control system for the defrosting evaporators of a refrigeration system which utilizes a first timer which runs continuously and attempts to initiate evaporator defrost at predetermined times and a second timer which accumulates compressor operating time and prevents defrost initiation by the first timer at those preselected times until a predetermined period of operation of the refrigerating system has occurred.

Abstract: This patent describes forced air heat exchangers using single phase A. C. motors to drive their fans and a method of securing high and low speed operation of the motors by connecting them alternately in delta and wye across a 3-phase power supply.