Fans with air
filters
Filter
Machines which have fans with air filters must
be checked at regular intervals and the filters
must be exchanged when necessary.
Remove the inlet protection screen and fit a
clean filter.
Remark
Note that the filter material has a different structure on each side. The side with the coarser structure
must be placed outward.
Machines
with heat
exchangers
See the chapter ”Motors equipped with heat
exchangers”
Specification of
filter material
If new filter material is to be bought, the
following specifications must be met by the
vendor:
a) The filter must be made of 100% continuous
glass fibre.
b) The filter must have an open structure at the
air intake side, but the fibre structure must
get tighter toward the air-exit side.
c) Allowed air flow 3 m/sec.
d) Tests according to ASHRAE-standard 52-76,
with an air flow of 2 m/sec., must show that:
- the pressure drop through a clean filter is
less than 60 Pa.
- the filter absorbs more than 90 % at a con-
tamination rate of 850 gram/m
2
(93 % for
the air-leakage filter.
- max. air pressure drop 200 Pa.
