Return and outside air shall be provided with air filter. Filter type and efficiency shall be based on the required cleanliness of the supply air, to meet the objectives of the conditioned space. Refer to filtration selection guideline of ASHRAE Systems and Equipment Handbook.
Rooms/spaces requiring chemical filtration shall be provided with a chemical filter unit to maintain a G1 class environment per ISA 71.04 requirements. Air for pressurization of the rooms/spaces not requiring a G1 environment need not pass through a chemical filter before entering the building.
Systems shall be provided with impingement type mechanical filters unless otherwise specified by Company.
Filters installed close to outside air inlet shall be protected from the weather by suitable louvers and large bird steel screen mesh 6 mm wire also shall be provided.
Filters shall have permanent indicators to give a warning thru HVAC DDC system when the filter resistance reaches the recommended change value to change or to maintain the filter.
Air filters shall be provided with access doors, sized to allow filter maintenance.
Disposable factory-fabricated mechanical panel filters shall meet the following requirements:
Filter media shall be interlaced glass fibers sprayed with non-flammable adhesive
Filter frame shall be cardboard, with perforated metal retainer
Extended-surface disposable panel filters shall meet the following requirements:
Filter media shall be a fibrous material formed into deep V-shaped pleats held by a self- supporting wire grid
Filter frame shall be non-flammable cardboard
All filters shall conform to UL 900 Class 2 for combustibility and smoke generation. Systems serving critical areas carrying flammable gases shall have the additional fire resistance of Class 1 filters when specified by SABIC.
Filtering efficiencies shall be in accordance with ASHRAE 52.
Glass fibrous media filter, having a 90-95 percent average atmospheric dust spot efficiency shall be provided for computer rooms.
The outside air chemical filtration or supply fan unit(s) shall- include both chemical and dust filters. Outside air entering the building/facility shall pass through a sand trap lover or inertial filter with bleed fan protected by bird mesh screen. The chemical filter media shall be selected to suit the environmental contaminants at the building/facility site.
Sand trap louver or inertial filter with bleed fan shall be used in outside air intakes for all systems.