Since the reduction of electrical power consumption continues to be a topical issue in the field of cooling necessary for the operation of cooling equipment, new solutions have been searched for to make cooling processes more efficient.
One of the solutions to reduce cooling capacity during the hot period when cooling facilities are most loaded and accordingly consume the greatest amount of power is adiabatic pre-cooling panels. The word pre-cooling in the name of this solution more accurately describes how the technology works – cooling of air inflowing to the cooling system.
How it works?
A micro nozzle panel is mounted before a collector of the cooling equipment producing fine, especially prepared water mist during the operation of a high pressure pump station. This mist, ending up in the warm air, becomes steam, and when liquid droplets turn into a gaseous aggregate state, the temperature drops. The lower the temperature is flowing into the conditioning system, the less power is needed to ensure the cooling process of the data centre in order to achieve the desired microclimate.
Each cooling facility is equipped by a manufacturer with information on data showing the system’s cooling capacity depending on the incoming (outdoor) air temperature. The use of adiabatic panels often helps to obtain significant power-saving, in some cases – up to 40%. However, one must remember that in this case, economy is a dynamic parameter that is affected by outdoor temperature fluctuations.
One of the main advantages of such systems is that they do not directly affect the work of the conditioning equipment. They only change the operational conditions of the equipment – for example, they “transfer” the equipment from a mode where it operates within an outdoor air temperature of +35C, to a mode where the outdoor temperature is +21C.
Adiabatic panels are constructed so that in addition to the reduction of the temperature during the evaporation process other additional features enhancing the cooling efficiency and achieving optimal use of the system are also ensured.
The solutions employ special sun reflective membranes that protect the conditioner’s coil and the radiator from the effects of direct sunlight (accordingly, from the raise of temperature which is heating air inflowing to the conditioning system).
The water, which in the form of mist is sprayed in the systems to reduce the inlet air temperature, is treated with special bio-additives to avoid lime-scale on the surface of the cooling equipment. The use of bio-additives guarantees the eco-friendly use of the product.
Adiabatic panels are compatible with a variety of cooling equipment designs. Panels with air-conditioning systems are attached with magnets, and the solution is mostly flexibly applicable.
The facilities are equipped with energy monitoring systems that allow the precise evaluation of energy savings after installation of the equipment. It is possible to record KW/h consumption before installation and consumption after installation of the equipment.
However, it must be noted that these types of systems have some work limitations:
1) The system is effective when the outdoor temperature is at least +25°C;
2) These systems are not effective in climatic zones with high humidity and/or short hot weather periods – hence the desired temperature reduction is not achieved. However even in geographical areas with adequate humidity and actual outdoor temperature in the hot period, including the Baltic states where the unit will operate for 1-2 months a year, energy savings and equipment preventing adverse effects caused by overload are frequently impressive and give reason to consider their installation;
3) The operation of the system in appropriate weather conditions ensures significant savings, however it also requires some expenses. They are mainly related to water consumption in order to ensure mist evaporation for the needs of the process. However, these expenses compared to the obtained effects are usually relatively small.
Since a data centre is a facility requiring very strict criteria for ensuring operational continuity, the use of such systems should be seriously considered. One should make sure of the system’s reliability, and assess the energy saving potential and financial benefits arising from such a system.