surrounding the equipment to be provided with the
vibration isolation units favorably influence the
effectiveness of the isolators. Where many items of
equipment require different transmission values,
based on the equipment location, the specification
may be revised to indicate the appropriate values on
the drawings.
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Refrigeration equipment and the installation thereof shall conform to
ASHRAE 15. Necessary supports shall be provided for all equipment,
appurtenances, and pipe as required, including frames or supports for
compressors, pumps, cooling towers, condensers, and similar items.
Compressors shall be isolated from the building structure. If mechanical
vibration isolators are not provided, vibration absorbing foundations shall
be provided. Each foundation shall include isolation units consisting of
machine and floor or foundation fastenings, together with intermediate
isolation material. Other floor-mounted equipment shall be set on not less
than a 150 mm 6 inch concrete pad doweled in place. Concrete foundations
for floor mounted pumps shall have a mass equivalent to three times the
weight of the components, pump, base plate, and motor to be supported. In
lieu of concrete pad foundation, concrete pedestal block with isolators
placed between the pedestal block and the floor may be provided. Concrete
pedestal block shall be of mass not less than three times the combined
pump, motor, and base weights. Isolators shall be selected and sized based
on load-bearing requirements and the lowest frequency of vibration to be
isolated. Isolators shall limit vibration to [_____] percent at lowest
equipment rpm. Lines connected to pumps mounted on pedestal blocks shall
be provided with flexible connectors. Foundation drawings, bolt-setting
information, and foundation bolts shall be furnished prior to concrete
foundation construction for all equipment indicated or required to have
concrete foundations. Concrete for foundations shall be as specified in
Section 03300A CAST-IN-PLACE STRUCTURAL CONCRETE. Equipment shall be
properly leveled, aligned, and secured in place in accordance with
manufacturer's instructions.
3.1.2
Mechanical Room Ventilation
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NOTE: For mechanical rooms which are intended to
house refrigeration equipment, designers will use
ASHRAE 15 to determine applicable design criteria.
Delete this paragraph if a mechanical room is not
applicable to the design.
In summary, ASHRAE 15 allows the use of either
natural or mechanical ventilation systems, however,
natural ventilation is allowed only in certain
limited applications. Natural ventilation is
allowed only when "a refrigerant system is located
outdoors more than 6.1 m (20 ft) from building
openings and is enclosed by a penthouse, lean-to or
other open structure", otherwise mechanical
ventilation is required.
The amount of ventilation air required for a
mechanical room will be determined based upon the
ventilation equations in ASHRAE 15. In order to use
these equations, a designer must approximate the
SECTION 15700A
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