located within an indoor space, a designer can use
the following 6-step synopsis as a guide in
determining "System Application Requirements" from
ASHRAE 15.
Step 1. Identify the safety group
classification of the refrigerant anticipated to be
used in the new refrigeration equipment.
Refrigerants R-22 and R-134a are considered Group A1
refrigerants. Refrigerant R-123 is considered a
Group B1 refrigerant. Ammonia is considered a Group
B2 refrigerant.
Step 2. Identify the occupancy classification
of the facility which will house the new refrigerant
equipment. Occupancies include institutional,
public assembly, residential, commercial, large
mercantile, industrial, and mixed types.
Step 3. Determine the system probability (high
or low) of the new refrigeration equipment. Split
system applications are typically considered
high-probability systems according to ASHRAE 15.
Step 4. Estimate the quantity of refrigerant
(grams or pounds) in the largest single refrigerant
circuit of the new equipment. The designer will
research catalog data from a minimum of 2 different
manufacturers in order to get an approximation.
Step 5. Determine the volume (cubic meters or
cubic feet) of the indoor space which is planned to
house the new refrigeration equipment.
Step 6. Identify the "System Application
Requirements" from the applicable table in ASHRAE 15
based upon the information identified in the
previous steps (e.g., safety group, occupancy,
system probability, refrigerant quantity, and indoor
space volume). The "System Application
Requirements" will dictate applicable refrigerant
limitations as well as occupied space or mechanical
room requirements.
ASHRAE 15 refers to a mechanical room as a machinery
room, however, the terms are synonymous. On
mechanical room design, ASHRAE 15 touches on
criteria concerning equipment placement, ventilation
design, door and passageway restrictions,
refrigerant monitoring, open-flame devices,
pressure-relief and purge piping. In addition to
mechanical room design, ASHRAE 15 also touches on
criteria concerning refrigerant piping, signs,
self-contained breathing apparatus (SCBA), and
miscellaneous installation restrictions. (SCBAs
cannot be considered MCA funded items and are
therefore not included in this specification.)
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SECTION 15652A
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