feet [_____] of the floor at the end of the throw.
2.7.5
Ceiling Diffusers
Equip with baffles or other devices required to provide proper air
distribution pattern [as indicated]. Provide factory-fabricated, single
key, volume dampers. Except for linear diffusers, internal parts shall be
removable through the diffuser neck for access to the duct and without the
use of special tools.
2.7.5.1
Circular, Square, and Rectangular Diffusers
Construct each ceiling diffuser of four or more concentric elements
designed to deliver air in a generally horizontal direction without excess
smudging of the ceiling. Interior elements of square and rectangular
ceiling diffusers may be circular, square, or rectangular as manufacturer's
standard.
2.7.5.2
Perforated Plate Diffusers
Provide adjustable [one-way,] [two-way,] [three-way,] [or] [four-way] air
pattern controls as indicated. Diffuser faceplates shall not sag or
deflect when operating under design conditions.
2.7.5.3
Linear Diffusers
Joints between diffuser sections shall appear as hairline cracks. Provide
alignment slots for insertion of key strips or other concealed means to
align exposed butt edges of diffusers. [Equip with plaster frames when
mounted in plaster ceiling.] Do not use screws and bolts in exposed face
of frames or flanges. Frames and flanges exposed below ceiling shall be
metal-filled and ground smooth. Furnish separate pivoted or hinged
adjustable air-volume-damper and separate air-deflection blades.
[2.7.5.4
Security Ceiling Diffusers
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NOTE: Use this paragraph for brig facilities only.
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Diffusers shall be steel with faceplate, fixed diffusion louvers, flat
surface margin, and an opposed blade damper. Faceplate shall be 14 gage
minimum with 15 by 15 mm holes on 5 mm 1/2 by 1/2 inch holes on 3/16 inch
spacing and a minimum free area of 45 percent.
]2.7.6
Registers
Double-deflection supply registers. [Provide manufacturer-furnished volume
dampers. Volume dampers shall be of the group-operated, opposed-blade type
and key adjustable by inserting key through face of register. Operating
mechanism shall not project through any part of the register face.
Automatic volume control devices will be acceptable.] [Provide exhaust and
return registers as specified for supply registers, except that exhaust and
return registers shall have a single set of nondirectional face bars or
vanes having the same appearance as the supply registers.] [Set face bars
or vanes at [_____] degrees.]
SECTION 15810N
Page 19
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