What is Indirect Evaporative Cooling Technology?

Indirect evaporative cooling technology, abbreviated as IEC, is a unique cooling method of evaporative cooling. When this technology is applied to data centers, the secondary air is mostly outdoor low-temperature fresh air, and the primary air is mostly the hot return air in the computer room. Taking the sensible heat temperature difference between the two as the driving force, the heat of the server is transferred to the outdoor air through the heat conduction of the heat exchanger tube wall, so as to achieve the purpose of cooling the return air of the data center.
The evaporative cooling system can also use water evaporation to absorb the heat in the outdoor secondary air through spraying.

The heat exchanger is reduced from dry bulb temperature to wet bulb temperature to cool the primary air in the computer room and enhance the refrigeration effect.
Indirect evaporative cooling system
The indirect evaporative cooling system is composed of spraying device, heat exchange core, indoor fan, outdoor fan, mechanical refrigeration supplementary device, control system, etc. The operation unit only needs to install air ducts, water pipes and power distribution on the data center site before it can be put into use.

The unit has three operation modes: dry mode, wet mode and hybrid mode.
(1) Dry mode, natural cooling
In winter, when the outdoor temperature is low, the outdoor air temperature is low enough to cool the return air of the server room in the heat exchanger. After passing through the heat exchanger, the outdoor air that absorbs heat is discharged outdoors by the fan wall.

The cooled return air of the computer room is sent to the server room through the indoor fan wall.
(2) Wet mode, evaporative cooling
In spring and autumn, when the outdoor temperature is relatively low, because the outdoor air temperature is not low enough, it is necessary to turn on the water pump to supplement the cooling capacity through adiabatic evaporative refrigeration by high-pressure micro mist spraying.
(3) Hybrid mode, mechanical supplementary cooling
In summer, when the outdoor temperature is high, natural cooling cannot meet the refrigeration demand. The circulating spray water takes away part of the heat, and the variable frequency compression refrigeration system is turned on to supplement the cooling capacity for the insufficient part.
The switching of the above three operation modes depends on the dry bulb temperature and wet bulb temperature of the outdoor air, and the boundary of determining the outdoor dry and wet bulb temperatures depends on the supply and return air temperatures of the data center computer room and the heat exchange efficiency of the indirect evaporative cooling heat exchange core.