**************************************************************************
Refrigeration systems which operate at pressures below atmospheric pressure
shall be provided with a purge system. Purge systems shall automatically
remove air, water vapor, and non-condensible gases from the system's
refrigerant. Purge systems shall condense, separate, and return all
refrigerant back to the system. An oil separator shall be provided with
the purge system if required by the manufacturer. Purge system shall not
discharge to occupied areas, or create a potential hazard to personnel.
Purge system shall include a purge pressure gauge, number of starts
counter, and an elapsed time meter. Purge system shall include lights or
an alarm which indicate excessive purge or an abnormal air leakage into the
system.
2.13
REFRIGERANT LEAK DETECTOR
**************************************************************************
NOTE: Refrigerant leak detectors will be provided
as required by the "System Application Requirements"
in ASHRAE 15.
When a detector is required, the location will be
indicated on the drawings. Detectors are best
located between the refrigeration system and the
room exhaust. Sampling points from a detector will
be located a maximum of 450 mm (18 inches) above the
finished floor since all commonly-used refrigerants
are heavier than air.
As a rule of thumb, the distance between any
refrigeration system and a refrigerant sampling
point shouldn't exceed 15 m (50 feet). In order to
meet the recommended 15 m (50 foot) distance, a
mechanical room can be provided with either multiple
detectors each with single sampling points or with
one detector that has the capability of monitoring
at multiple sampling points. If multiple sampling
points are required, enter the number in the
appropriate blank below.
Per ASHRAE 15, when a detector senses refrigerant it
must activate an alarm and initiate the room
ventilation system. In regards to alarms, as a
minimum indicate that the detector will energize a
light on or near the detector as well as a second
light installed on the outside wall next to the
mechanical room entrance. The exterior light will
be provided with a sign that warns personnel
entering the mechanical room of a refrigerant
release and that a SCBA is required to enter. If
applicable to the installation, include an audible
alarm on the exterior of the mechanical room.
Include the electrical design for the alarm system
on the drawings.
As an additional item, ASHRAE 15 states that
open-flame devices (i.e., boilers, etc.) cannot be
installed in the same area as a refrigeration
system, unless either combustion air for the
SECTION 15652A
Page 28
Previous Page
