Acoustically and thermally insulate internal surfaces of units, air
diffusers, and accessories. Surface coat the insulation to prevent erosion.
2.8.3
Controls
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NOTE: Select one of the following paragraph as
appropriate. Direct digital controls shall only be
used with the approval of the Engineering Field
Division, Code 403.
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[Provide controls in accordance with Section 15901N SPACE TEMPERATURE
CONTROL SYSTEMS.]
[Provide controls in accordance with Section 15910N DIRECT DIGITAL CONTROL
SYSTEMS.]
[[Pneumatic], [Electric], [or] [Duct-pressure-powered] type. All
thermostatic air-volume controls shall be pressure [independent]
[dependent] type.]
2.8.4
Air-Volume Regulators
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NOTE: For electric heat, use 30 percent for minimum
regulator setting. Otherwise, use 25 percent for
minimum regulator setting. In addition to regulator
VAV units, there are pressure independent
system-powered VAV units available. These
system-powered VAV units do not require
energy-consuming external controls. The
system-powered VAV units can only maintain the set
air flow quantity plus or minus ten percent, twice
as much as permitted in Navy air leakage tests for
ducts of pressure class 750 Pa or less 3 inch or
less water gage. In some project locations,
system-powered VAV units may be considered by the
designer, if and only if economic and life cycle
analysis can justify.
**************************************************************************
Static-pressure-compensated or velocity-pressure type. At any damper
position, maintain constant-volume L/s cfm within plus-or-minus 5 percent
of design-rated L/s cfm setting. Provide factory-fabricated and
field-adjustable set-points to set maximum and minimum L/s cfm.
2.8.5
Air Diffusers
[Fixed] [or] [Variable] type. Construct diffusers to operate without loss
of Coanda effect. [Provide remote diffusers with integral boots and
bellows or dampers.]
2.8.6
Reheat Coils
2.8.6.1
Water Coils
One-row or two-row hot water coils for [_____] degrees C degrees F
temperature differential, with entering water temperature at [_____]
SECTION 15720N
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