Supply and exhaust air purification:
99,9% (in amount) of particulates in the outdoor air are smaller than 1 mm. By mass the mentioned particulates account for only 30% of all air borne dust. Thus, if outdoor air is supplied to the public and dwelling houses, to ensure air purity required by hygienic standards, filters of EU5-EU7 class are enough. EU4 and EU5 class filters are used for filtering the exhaust air in air handling units. Air filtering protects air handling equipment against pollution, extends its service life. Therefore dirty filters should be replaced on a timely basis to assure comfortable conditions in the premises and protection of air handling units against breakage. A light on the control panel indicates filter clogging. Usually air filters should be replaced not less than twice per year: after the end of the heating season and in autumn.
Types of filters:
- F5 (standard filters) or F7 (optional) class filters for supply air filtery. Very compact, but are distinguished by extra large filtering surface. Large filtering surface provides long-life performance and low pressure losses (low pressure losses reduce power consumption). The filters from glass fibre material and a paper filter case. Ecologically clean materials allow just to burn clogged air filters.
- G4 class filter is intended for exhaust air filtering, protecting fan and heat exchanger of possible impurities.
Filter classification and standards:
Filters applied in the air handling units are classified according to EUROVENT 4/9 (CEN EN 779 and CEN EN 1882) system.
