Honeywell 11255 - Manual (Page 70)

70
Guide Specifications
Application Guidelines
Precision Pak filters should be selected using 24” x
12” 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 filters should be installed with pockets
vertical wherever possible. It is acceptable to install
24” x 12” face size filters with pockets horizontal if
necessary to meet the size requirements of the filter
banks.
Gasketed Headers
Precision Pak filters installed in Flanders K-Trac
Filter Framing Modules or Sureseal Side Access
Housings require polyfoamgaskets on opposite
header sides to prevent air bypass. To specify
Precision Pak filters with gasketed headers, add
suffix ”S” or “H” to the model number.
Prefilters
Properly selected bag filters without prefilters will
generally require changeout annually in typical
HVAC applications. Because of the frequent main-
tenance expense and increase in fan kW input using
prefilters, they are often recommended with 85%
and 95% efficient Precision Pak final filters.
However, the energy cost to operate a prefilter sel-
dom warrants their use with 55% or 65% filters.
1.0 General
1.1 Medium and high efficiency self-supporting filters
shall be Precision Pak extended surface type as
manufactured by Flanders.
1.2 Filter sizes, efficiencies and capacities shall be
as scheduled on the drawings.
2.0 Filter Construction
2.1 Filters shall be constructed of lofted fiberglass or
micro-fine synthetic media encased in a thin non-
woven polyester backer mat.
2.2 Open area on the filter face for air passage shall
be not less than 90%.
2.3 Flexible internal support stitching shall maintain
individual pockets in a controlled form under all
rated air flow conditions.
Stitchings shall be
sealed with thermoplastic sealant. Edges shall
be finished with overlock stitch to prevent air
unravelling.
2.4 Pockets shall be 100% stake-through crimped to
prevent media pull-out
2.5 Pockets shall be bonded to corrosion-resistant
steel casings and assembled into a corrosion-
resistant steel header.
2.6 Filters shall be UL 900 Class 2 or Class 1 listed.
3.0 Performance
3.1 Initial and final resistances shall not exceed the
scheduled values.
3.2 Media area must equal or exceed that of the spec-
ified filter.
3.3 The average efficiency shall be as determined by
the ASHRAE Standard 52.1 test methods.
3.4 The manufacturer shall guarantee performance
as stated in its literature within tolerances as out-
lined is Section 7.4 of ARI Standard 850.
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