INDUSTRY INTELLIGENCE POWERED BY THE DCA
Expert discusses air filters and air conditioning and handling units
Peter Dyment , Technical Manager – Camfil Ltd , discusses the purpose and function of air filters and how they should be best utilised to ensure optimum data centre performance .
Data centre reliability is a top priority for data centre leaders and so must be acknowledged and ensured . Air filters must be best positioned to deal with the source of airborne contamination .
High concentrations of airborne contaminants combined with higher humidity levels will usually show increased rates of equipment failure in data centres .
Air filters used to clean incoming supply air from outside and recirculated inside air must be capable of removing airborne particles and also corrosive gases when present . Tin or zinc whiskers can be an internal source of airborne contamination as well as white rust particles .
There is an increasing use of free cooling to reduce energy consumption in data centres . Use of outside air at lower temperature introduced directly into the data centre server hall can offer large reductions in Power Usage Effectiveness ( PUE ).
The current recommended particle filter class for data centre supply air systems is minimum BS EN ISO 16890:2016 ePM1 50 % and for recirculated air systems is coarse 70 %, the equivalent as recommended by ASHRAE in 2011
Gaseous and Particulate Contamination Guidelines for Data Centres . Air monitoring can be used to determine the concentrations of particles and corrosive gases present . Some air monitoring devices now include air cleaner / purifier control functions .
It is recommended that particle concentrations in data centre operational equipment areas align to meet the requirements of ISO Standard 14644-1 Class 8 .
For corrosive gases , it is recommended that monitored levels of corrosion meet the requirements of ISA Standard 71.04- 1985 to meet class G1 Mild .
Where monitored levels of corrosion exceed this , then gas phase filtration needs to be used . Molecular gas filtration can be fitted to the main supply ventilation system or applied by use of standalone recirculation units .
To target individual contaminant gases , filters tested to BS EN ISO 10121-2:2013 can be used . Broad spectrum filters can be used to target a combination of gases .
Air filters consume significant amounts of electrical energy through the fan motor , so selection of low energy air filters is recommended . www . intelligentdatacentres . com
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