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.

A chiller including a heat transfer tube and a method for controlling a chiller to determine a degree of contamination of a heat transfer tube are provided. As a degree of contamination of the heat transfer tube may be determined and a notification provided to a user regarding whether to clean the heat transfer tube, the chiller may be managed efficiently and an operation performance of the chiller may be maintained well.

The disclosed technology includes a method for identifying and determining a fault or a potential fault in an air system having an outdoor unit and an indoor unit in fluid communication via a refrigerant circuit. The method can include receiving, from a sensor, vibration data indicative of one or more sounds or vibrations detected by at least a portion of the refrigerant circuit. The method can include identifying, based at least in part on the vibration data and stored baseline vibration data, an abnormality in the vibration data. The abnormality can be indicated by vibration data indicative of a frequency that is outside a range of acceptable frequencies. The method can include analyzing the identified abnormality according to a predetermined set of evaluation factors to determine the fault or the potential fault.

A control system for a cooling system configured to selectively operate one or both of a condenser fan an evaporator fan in a reverse direction RD, measure power draw at the motor against configuration data and fan motor profiles, and determine if a blockage has occurred before the static pressure has reached a critical point static pressure where the efficiency, performance, and cooling capability of the cooling system is hindered and maintenance is required to clear the blockage. By determining if blockage has occurred before the static pressure has reached the critical point static pressure, an alert or corrective action can be taken.

A method of detecting airflow blockage of a transport refrigeration system including the steps of: activating a heater powered by an electric generation device; measuring an output voltage of the electric generation device; determining a predicted heat output of the heater in response to the output voltage; determining a predicted temperature rise across the heater in response to the predicted heat output; detecting a measured temperature rise across the heater; and determining an airflow reduction percentage in response to the predicted temperature rise across the heater and the measured temperature rise across the heater.

An access device for installation to a condensation drainage system, such as a drain line of an HVAC unit, includes a main body with connecting ports at opposite ends for sealed, fluid flow inline connection to the drainage system. A top cover releasably secures to the main body to completely cover and seal an open top and interior cavity. A cleanout adapter has a flange that surrounds a bottom opening. The flange includes a seal around its outer periphery and is structured for sliding receipt within either of two transverse slots within the interior cavity to position the bottom opening of the adapter in sealed alignment with either of the connection ports, whereby a pressurized gas or liquid flow source, or a vacuum source can be connected to a top opening of the adapter for clearing a clog in the drain line either upstream or downstream of the access device.

Provided are an air conditioner and a control method thereof. The control method includes following steps: controlling a compressor of an air conditioner to be in an operating state or a shutdown state according to a superheat degree of injected vapor of the compressor and a continuous duration of the superheat degree; controlling the compressor to be in a shutdown state for maintenance according to a number of shutdown times of the compressor, so as to maintain a gas supply pipeline of the compressor. By adopting such a configuration, an operating condition of the compressor can be accurately and effectively determined, which enables the compressor to be maintained timely, thereby preventing the compressor from being damaged as a result of operating in a severe condition, and enhancing operation reliability of the compressor and the air conditioner.

A direct evaporative cooler includes a liquid delivery system and an assembly of two or more plates. At least one plate of the assembly of two or more plates may include a top surface having a wicking material with an exposed surface for receiving a liquid thereon from the liquid delivery system, and one or more masks lining a portion of the exposed surface. The one or more masks may be impermeable to the liquid thereby preventing the liquid from evaporating through the one or more masks, and the one or more masks may be sized and shaped such that a wick rate of the liquid on the exposed surface exceeds an evaporation rate of the liquid.

A heat cycle system is a heat cycle system (1) using a working medium containing hydrofluoroolefin (HFO) that has a double bond in a molecule structure, the heat cycle system (1) having a compressor (10), a high-pressure side heat exchanger (12), a low-pressure side heat exchanger (14), an expansion mechanism (13), and an acid detection means (40) which is disposed in a discharge pipe (21) connecting the compressor (10) and the high-pressure side heat exchanger (12) and which detects acid generated by decomposition of the working medium in a heat cycle.

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.