Abstract: In one instance, a cooling unit for use as an aspect of a cooling system includes a cabinet having a plurality of panels and having an interior, a front face with a fan aperture formed in the front face, and a bottom panel. The cooling unit further includes a drain pan below the bottom panel. The cooling unit also includes a plurality of guide-rail slide and track assemblies coupled between at least a portion of the cabinet and the drain pan for providing controlled movement of the drain pan between an operational position and a maintenance position. Other cooling units are disclosed with drain pans that may be lowered by a single technician.

Abstract: A cooling system drains oil from low side heat exchangers to vessels and then uses compressed refrigerant to push the oil in the vessels back towards a compressor. Generally, the cooling system operates in three different modes of operation: a normal mode, an oil drain mode, and an oil return mode. During the normal mode, a primary refrigerant is cycled to cool one or more secondary refrigerants. As the primary refrigerant is cycled, oil from a compressor may mix with the primary refrigerant and become stuck in a low side heat exchanger. During the oil drain mode, the oil in the low side heat exchanger is allowed to drain into a vessel. During the oil return mode, compressed refrigerant is directed to the vessel to push the oil in the vessel back towards a compressor.

Abstract: An HVAC system includes a unit cooler, which includes a first evaporator coil, a second evaporator coil, and a blower. The HVAC system further includes a first sensor, a second sensor, a first valve, a second valve, and a controller. The controller actuates the blower to direct air to flow over the first evaporator coil and the second evaporator coil, receives measurements from the first sensor and the second sensor, initiates a defrost cycle for the first evaporator coil by transmitting instructions to close the first valve to prevent the flow of refrigerant into the first evaporator coil, transmits instructions to open the first valve when the defrost cycle for the first evaporator coil has terminated, and initiates a defrost cycle for the second evaporator coil by transmitting instructions to close the second valve to prevent the flow of refrigerant into the second evaporator coil.

Abstract: In one embodiment, an apparatus includes an insert for an evaporator coil. The insert is a curved wire located within the evaporator coil. The insert for the evaporator coil reduces refrigerant charge in the evaporator coil and causes refrigerant flowing through the evaporator coil to change direction.

Abstract: A cooling system partially floods the low temperature low side heat exchangers (e.g., freezers) in the system. An accumulator is positioned between the low temperature low side heat exchangers and the low temperature compressor. The accumulator collects the refrigerant (both liquid and vapor) from the flooded low temperature low side heat exchangers. Refrigerant discharged by the low temperature compressor is fed through the accumulator so that heat can be transferred to the refrigerant collected in the accumulator. As a result, the temperature of the refrigerant discharged by the low temperature compressor drops before that refrigerant reaches the medium temperature compressor.

Abstract: An adiabatic cooling system includes a condenser coil and one or more adiabatic pads positioned such that intake air for the adiabatic cooling system passes through the pads prior to contacting the condenser coil. The adiabatic cooling system includes a vibration device attached to each adiabatic pad. A controller is communicatively coupled to the vibration device for each of the adiabatic pads. The controller determines that cleaning of the adiabatic pads is needed. In response to detecting cleaning is needed, the controller causes the vibration device attached to each adiabatic pad to vibrate, thereby causing debris in the one or more adiabatic pads to become loosened and/or removed from the adiabatic pads.

Abstract: A cooling system drains oil from low side heat exchangers to vessels and then uses compressed refrigerant to push the oil in the vessels back towards a compressor. Generally, the cooling system operates in three different modes of operation: a normal mode, an oil drain mode, and an oil return mode. During the normal mode, a primary refrigerant is cycled to cool one or more secondary refrigerants. As the primary refrigerant is cycled, oil from a compressor may mix with the primary refrigerant and become stuck in a low side heat exchanger. During the oil drain mode, the oil in the low side heat exchanger is allowed to drain into a vessel. During the oil return mode, compressed refrigerant is directed to the vessel to push the oil in the vessel back towards a compressor.

Abstract: A refrigeration system includes a dedicated defrost-mode compressor that delivers high pressure, high temperature refrigerant to one or more evaporators to defrost the evaporators.

Abstract: An adiabatic cooling system includes a condenser coil and at least one mist chamber positioned around the condenser coil such that at least a portion of intake air for the adiabatic cooling system passes through the mist chamber prior to contacting the condenser coil. The at least one mist chamber includes a first cooling pad with a first intake-side face and a first output-side face and a second cooling pad with a first intake-side face and a first output-side face. The second-intake side face of the second cooling pad faces the first output-side face of the first cooling pad and is separated from the first-output side face of the first cooling pad by a gap. At least one nozzle is configured, when the adiabatic system is operating in a wet mode, to provide a mist of water into the gap.

Abstract: An apparatus includes a high side heat exchanger, a heat exchanger, a flash tank, a first expansion valve, a second expansion valve, a load, a first compressor, and a second compressor. During a first mode of operation, the second expansion valve directs refrigerant from the flash tank to the load. The refrigerant from the load bypasses the first compressor. The heat exchanger transfers heat from the refrigerant from the high side heat exchanger to the refrigerant from the load. The second compressor compresses the refrigerant from the heat exchanger. During a second mode of operation, the first expansion valve directs refrigerant from the flash tank to the load. The first compressor compresses the refrigerant from the load and the second compressor compresses the refrigerant from the first compressor before the refrigerant from the first compressor reaches the high side heat exchanger.

Abstract: A method by a controller of a cooling system includes calculating a difference between a first temperature of ambient air and a second temperature of pre-cooled air. The pre-cooled air is ambient air that has been cooled by water from a water distribution system before it enters one or more condenser coils. The method further includes determining that the difference between the first and second temperatures is less than or equal to a predetermined temperature difference, and in response, determining that the first temperature is greater than or equal to a minimum temperature. The method further includes, if the first temperature is greater than or equal to the minimum temperature, instructing the water distribution system to distribute the water to pre-cool the ambient air for a predetermined length of time and to disable the distribution of the water after the predetermined amount of time has elapsed.

Abstract: A system includes a flash tank and a thermal storage tank. The flash tank is configured to store refrigerant and discharge a flash gas. The thermal storage tank is fluidically coupled to the flash tank and configured, when a power outage is determined to be occurring, to receive at least a portion of the flash gas from the flash tank, and remove heat from the flash gas. When a power outage is determined not to be occurring, the thermal storage tank directs refrigerant to a compressor.

Abstract: A system includes a high side heat exchanger, a flash tank, a first load, a second load, and a thermal storage tank. The high side heat exchanger is configured to remove heat from a refrigerant. The flash tank is configured to store the refrigerant from the high side heat exchanger and discharge a flash gas. The first load is configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load. The thermal storage tank is configured, when a power outage is determined to be occurring, to receive at least a portion of the flash gas from the flash tank, and remove heat from the flash gas.

Abstract: In one instance, a cooling unit for use as an aspect of a cooling system includes a cabinet having a plurality of panels and having an interior, a front face with a fan aperture formed in the front face, and a bottom panel. The cooling unit further includes a drain pan below the bottom panel. The cooling unit also includes a plurality of guide-rail slide and track assemblies coupled between at least a portion of the cabinet and the drain pan for providing controlled movement of the drain pan between an operational position and a maintenance position. Other cooling units are disclosed with drain pans that may be lowered by a single technician.

Abstract: A cooling system drains oil from low side heat exchangers to vessels and then uses compressed refrigerant to push the oil in the vessels back towards a compressor. Generally, the cooling system operates any number and combination of three different modes of operation: a normal mode, an oil drain mode, and an oil return mode. During the normal mode, a primary refrigerant is cycled to cool one or more secondary refrigerants. As the primary refrigerant is cycled, oil from a compressor may mix with the primary refrigerant and become stuck in a low side heat exchanger. During the oil drain mode, the oil in the low side heat exchanger is allowed to drain into a vessel. During the oil return mode, compressed refrigerant is directed to the vessel to push the oil in the vessel back towards a compressor.

Abstract: A cooling system drains oil from low side heat exchangers to vessels and then uses compressed refrigerant to push the oil in the vessels back towards a compressor. Generally, the cooling system operates in three different modes of operation: a normal mode, an oil drain mode, and an oil return mode. During the normal mode, a primary refrigerant is cycled to cool one or more secondary refrigerants. As the primary refrigerant is cycled, oil from a compressor may mix with the primary refrigerant and become stuck in a low side heat exchanger. During the oil drain mode, the oil in the low side heat exchanger is allowed to drain into a vessel. During the oil return mode, compressed refrigerant is directed to the vessel to push the oil in the vessel back towards a compressor.

Abstract: A cooling system implements various processes to improve efficiency in high ambient temperatures. First, the system can flood one or more low side heat exchangers in the system. Second, the system can direct a portion of vapor refrigerant from a low side heat exchanger to a flash tank rather than to a compressor. Third, the system can transfer heat from refrigerant at a compressor suction to refrigerant at the discharge of a high side heat exchanger.

Abstract: A cooling system uses P-traps to address the oil return issues that result from a vertical separation between the compressor and the high side heat exchanger. Generally, the vertical piping that carries the refrigerant from the compressor to the high side heat exchanger includes P-traps installed at various heights to capture oil in the refrigerant and to prevent that oil from flowing back to the compressor. As oil collects in the P-traps, the refrigerant begins to push the oil upwards until the oil reaches the high side heat exchanger. Multiple piping of different sizes may be used depending on a discharge pressure of the compressor. When the discharge pressure is higher, a larger piping may be used direct the oil and refrigerant to the high side heat exchanger.

Abstract: A system includes a flash tank, a first load, a second load, a first compressor, a second compressor, a first valve, and a second valve. The flash tank stores a refrigerant. The first and second loads use the refrigerant to cool first and second spaces. The first compressor compresses the refrigerant from the first load during a first mode of operation and a flash gas from the flash tank during a second mode of operation. The second compressor compresses a mixture of the refrigerant from the first and second loads during the first mode of operation. The first valve directs the flash gas from the flash tank to the first compressor during the second mode of operation. The second valve directs the compressed flash gas from the first compressor to the first load during the second mode of operation to defrost the first load.