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Operation and Maintenance
Envistar Top 04-21
DSET.220501.07.en
Continuous product development may give rise to specification changes without notice.
6.2 Filters (code ELEF)
00032
1
1. Filter
The air filters in an air handling unit are designed to prevent dust and other
impurities from entering the building. They should also protect sensitive com-
ponents inside the unit, e.g. water coils and heat exchangers, from exposure to
impurities.
The dust separation efficiency varies considerably between various filter types.
The dust collecting efficiency also varies substantially.
It is therefore important to use filters of the same quality and capacity when you
change them.
According to guidelines for hygienic design VDI 6022 Part 1: The supply air filter
must be class ePM1-50% (F7) or have a greater filtration efficiency.
The filters are designed for one-time use. If they become fouled, the unit will lose
capacity. The filters should therefore be changed if the pressure drop across
them exceeds the specified final pressure drop.
It is important to stop the unit before changing filters to prevent dust from
coming loose and being drawn into the unit. The inside surfaces of the filter
sections should therefore also be cleaned when the filters are changed.
Lifespan and filter control Carbon filter
The function and lifespan of the carbon filters depends on the volume of air that
passes through and on the molecular density of odorous substances. This me-
ans that the time intervals for filter replacement can vary from unit to unit depen-
ding on operation mode and the volume of odorous substances in the air.
Units delivered with control equipment (code MX) are equipped with the filter
control function – FLC (Filter Lifetime Control). FLC indicates when it is time to
replace the carbon filter. Indication is through an alarm on the Climatix display.
