Honeywell 11255 manual Application Guidelines, VAV Systems, Gasketed Headers, Prefilters

Application Guidelines

Precision Pak XDH filters should be selected using 24” x 12” and 24” x 24” face sizes. This allows for 12” increments in height and width of the filter bank and insures that replacement filters will be readily available.

Precision Pak XDH filters should be installed with pockets vertical wherever possible. It is acceptable to install 24” x 12” face size filters with pockets hor- izontal if necessary to meet the size requirements of the filter banks.

VAV Systems

VAV systems can be designed using the full range depth of Precision Pak XDH filters. Filter banks should be sized so that the maximum rated flow at design conditions falls within the published recom- mended velocities. Precision Pak XDH filters in all standard depths can be applied at any capacity between zero flow and catalog-rated capacities.

Gasketed Headers

Precision Pak XDH filters installed in Fland rs K- Trac Filter Framing Modules or Sures al Side Access Housings require polyfoam gask ts on opposite header sides to prevent air bypass.

To specify Precision Pak XDH filters with gasketed headers, add suffix “S” or “H” to the m del number. Use “S” gaskets on the sides parallel the pockets and “H” for gaskets on sides perpendicular to the pockets.

Prefilters

Properly selected bag filters without prefilters will generally require changeout annually in typical HVAC applications. Be ause of the frequent main- tenance expense and in rease in fan kW input using prefilters, they re seldom recommended on lower efficiency fin l filters. However, prefilters are often used on 85% nd 95% efficiency applications.

Guide Specifications

1.0 General

1.1 Medium and high efficiency self-supporting filters		2.4 Pockets shall be bonded to galvanized steel cas-
		ings and assembled into a galvanized steel
shall be Precision Pak XDH extended
		header with reverse-hemmed edges for safety.
surface type as manufactu ed by Flanders.
		2.5 Headers shall be gasketed with polyfoam on
1.2 Filter sizes, efficiencies and capacities shall be
		vertical sides to prevent leakage when installed
as scheduled on the drawings.
		in framing modules or Side Access Housings.
2.0 Filter Construction		2.6 Filters shall be UL 900 Class 2 listed.
2.1 Filters shall be cons ruc ed of polyolefin micro-		3.0 Performance
fine synthetic media encased in a thin non-
		3.1 Initial and final resistances shall not exceed the
woven polyester backer mat.
		scheduled values.
2.2 Open area on the lter face for air passage shall
		3.2 Media area must equal or exceed that of the
be not less than 90%.
		specified filter.
2.3 Flexible internal support stitching shall maintain
		3.3 The average efficiency shall be as determined by
individual pockets in a controlled form under all
		the ASHRAE Standard 52.1 test methods.
rat d	air flow conditions. Stitching shall be
s al	d with thermoplastic resin. Edges shall be	3.4 The manufacturer shall guarantee performance
finish	d with a four-thread overlock stitch to pre-	as stated in its literature within tolerances as
vent air bypass.		outlined is Section 7.4 of ARI Standard 850.

Flanders - Foremost in Air Filtration

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