mass of refrigerant (kgs or lbs) expected in the
largest system located in the mechanical room.
Refrigerant quantities will be determined based upon
a minimum of 2 different system manufacturers.
a. For a natural ventilation system, ASHRAE 15
provides an equation for sizing the amount of free
opening area required.
b. For a mechanical ventilation system, ASHRAE
15 requires both normal and alarm ventilation.
Normal ventilation will be sized to cover personnel
ventilation requirements (2.5 1/s/m2 or 0.5 cfm/ft2)
and heat buildup requirements if applicable. Alarm
ventilation will be sized based upon the equations
in ASHRAE 15. Both the normal and alarm ventilation
rates can be achieved using the same ventilation
system (e.g., multi-speed exhaust fans), however,
individual systems are preferred. For the alarm
ventilation, exhaust intakes will be located near
the equipment and close to the finished floor. Most
commonly used refrigerants are heavier-than-air and
subsequently sink to the floor. Also per ASHRAE 15,
air supply and exhaust ducts to the mechanical room
will serve no other area within a facility.
Discharge air from a mechanical ventilation system
will be to the outdoors.
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Mechanical ventilation systems shall be in accordance with Section 15895
AIR SUPPLY, DISTRIBUTION, VENTILATION, AND EXHAUST SYSTEM.
3.1.3
Field Applied Insulation
Field applied insulation shall be as specified in Section 15080A THERMAL
INSULATION FOR MECHANICAL SYSTEMS, except as defined differently herein.
3.1.4
Field Painting
Painting required for surfaces not otherwise specified, and finish painting
of items only primed at the factory are specified in Section 09900 PAINTS
AND COATINGS.
3.2
CLEANING AND ADJUSTING
Equipment shall be wiped clean, with all traces of oil, dust, dirt, or
paint spots removed. Temporary filters shall be provided for all fans that
are operated during construction, and new filters shall be installed after
all construction dirt has been removed from the building. System shall be
maintained in this clean condition until final acceptance. Bearings shall
be properly lubricated with oil or grease as recommended by the
manufacturer. Belts shall be tightened to proper tension. Control valves
and other miscellaneous equipment requiring adjustment shall be adjusted to
setting indicated or directed. Fans shall be adjusted to the speed
indicated by the manufacturer to meet specified conditions. Testing,
adjusting, and balancing shall be as specified in Section 15990A TESTING,
ADJUSTING, AND BALANCING OF HVAC SYSTEMS.
SECTION 15700A
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