Suspended/Mounted Mechanical Equipment. Where suspended and
mounted equipment is installed, provide a minimum of 1700 mm (67 in) of
clearance for headroom as required. In refrigeration equipment rooms,
provide overhead clearances required by ASHRAE 15, (reference 8j). For any
work station or location requiring maintenance access, which is not readily
accessible from a 1800 mm (6 ft) high portable ladder, provide a fixed
ladder and/or catwalk.
Air Distribution System Components. Outdoor air intake
plenums, air handling unit casings, and distribution ductwork shall be
designed to permit access for periodic cleaning or disinfection.
HVAC System Balancing Provisions. Adequate access shall be
provided to facilitate operation, adjustment, and testing at all HVAC
balancing and measuring points and equipment, including automatic and
manual damper operators, air terminal units, pilot tube ports, valves, and
Vibration Control. All prime moving equipment shall be isolated
to prevent transmission of vibrations to the structure. Additional
information and requirements addressing vibration control are contained at
Section 23, Acoustics, of this military handbook.
Fire Protection Features.
Smoke and Fire Dampers. HVAC service zones should be designed
to coincide with smoke zones whenever practicable. Ductwork penetrations
of fire/smoke rated walls should be minimized, to minimize the required
number of smoke/fire dampers and complexity of controls. Coordinate with
the architectural design to assure that necessary access for inspection or
service of these dampers is provided.
Ductwork. Air supply and exhaust systems shall be of the
mechanical ventilation type and shall meet the requirements of NFPA 90A and
96, (references 8d and 8e). If used, duct lining materials shall meet the
smoke generation and flame spread limitations as required by MIL-HDBK-1008,
(reference 8p). Grease-laden vapor exhaust ductwork shall be in accordance
with NFPA 96.
Smoke Mode Operation . Air handling and distribution systems
shall react to the detection of smoke in accordance with NFPA 101 and 90A.
Where required by NFPA 101, NFPA 99, or ANSI A17.1, smoke evacuation or
venting features shall be provided.
typically do not contain provisions for the simultaneous testing of HVAC
and fire protection systems, which can have complex, interwoven operational
requirements in some facilities. For each project where applicable,
designers shall develop or modify specifications as needed to provide for
testing of HVAC systems under fire alarm conditions, to permit verification
not only of correct function, but of acceptable speed of response. In
more complex systems involving smoke evacuation or
compartmentalization/pressurization, detailed testing protocols and/or