tests by an AMCA approved laboratory.
2.10.1.2
Retarding Agent
An ultraviolet retarding agent such as additives, gel coatings or other
manufacturer approved equivalents shall be part of or applied on exterior
nonmetallic components susceptible to ultraviolet degradation from sun rays
and shall conform to UL 746C.
2.10.2
Evaporative Media
2.10.2.1
Evaporative and Eliminator Media for [_____] Type Units
Media shall be fabricated of [wood aspen fibers,] [refined cellulose
matrix,] [bonded synthetic fiber,] [glass fiber,] [nonferrous metal].
Media shall conform to UL 900 Class II. Media shall be of the type
specifically manufactured for use with evaporative coolers. Nonferrous
metal media shall be constructed of corrosion and fungus resistant material
not susceptible to decomposition by fungal or bacterial action.
[Eliminator media shall be provided for slinger-type systems.] Media-pad
face velocities shall not exceed [1.27 m/s (250 fpm) 250 fpm for wood aspen
fiber]. Media shall be securely mounted in a galvanized steel, stainless
steel, or polymeric material frame. Louvers shall be positioned in such
manner that the water will not run on the outside surface. Nonrigid filter
media shall be held in frame by a rigid retainer grid, a 6 mm (1/4 inch)
1/4 inch wire mesh or fabric netting.
2.10.2.2
Evaporative Media for Rotary-Type Units
The evaporative filter unit shall be either drum or disk type. Media shall
be fabricated of copper, bronze, or polymer material. No moisture
entrainment shall occur. Where necessary to prevent such entrainment,
eliminator media constructed of copper, copper alloy, or polymer material
shall be provided. Face velocities shall be limited to those recommended
by media manufacturer.
2.10.3
Water Handling Equipment
2.10.3.1
Water Handling Equipment for Drip Coolers
Water handling equipment shall thoroughly wet and continuously flush
evaporative surfaces of the media material. The water distribution system
shall be designed, to provide equal flow of water directly to the pads or
to each trough. Troughs, if used, shall be adjustable hot-dip galvanized
steel, stainless steel, or polymeric and suitably designed in a manner that
will effectively regulate the flow of water to the media pad to obtain even
and complete saturation. Troughs shall be adjustable for leveling or
sectionalized and each section supplied with water by means of an
individual tube. The water pump shall be a centrifugal type with capacity
and head characteristics for the specified operation of the unit and shall
be provided with a low water safety shut-off. The motor shaft shall be
constructed of stainless steel, hot-dip galvanized steel or cadmium coated
steel. The impeller shall be constructed of stainless steel or polymeric
material conforming to UL 746C. Pump housing shall be constructed of
[painted] [hot-dip zinc coated] steel, brass, or polymeric material
conforming to UL 746C. Pump housing bottom shall be removable for impeller
cleaning and shall not permit galvanic action with cooler bottom. Pump
shall have permanently sealed and lubricated bearings and fan cooled motor
with moisture proof winding. Pump motor shall be provided with a factory
SECTION 15690A
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