Water Circuits
For systems using an indirect cooling circuit, there is a possibility of accidental release of
refrigerant into the secondary circuit from a rupture of the evaporator or condenser wall.
This should be dealt with by one of the following options:
Incorporate an air vent/air separator within the secondary circuit, on the outlet pipe
from the evaporator or condenser. Ensure that it is adequately sized such that it will
release any refrigerant back into the housing, machinery room, special area or to the
outside. This release can then be dealt with as any normal refrigerant release from
the primary circuit.
Use a ‘double-walled’ heat exchanger, of the type that is laser-welded, designed such
that it can only vent to atmosphere rather than the secondary circuit in the event of
damage.
2.6.3 Machinery Rooms
Machinery rooms for systems using DURACOOL® refrigerants shall be designed to
prevent the ignition of a refrigerant/air mixture. There should be warning notices stating
that smoking, potential ignition sources or flames are prohibited. Fire extinguishers
should be available and should provide clear instructions.
Machinery rooms must not be constructed out of combustible materials. If it is possible
for the concentration of refrigerant to reach the Lower Flammability Limit (LFL) then
some explosion relief should be provided in the construction of the machinery room. This
may be in the form of movable panels or louvers.
Protect all refrigerant containing machinery so that damage from external sources would
be difficult.
NOTE: although a machinery room does not necessarily serve exclusively for refrigeration
equipment, boilers and other open flame devices should not share the space
. Air intakes
for equipment should not be taken from within the machinery room, or close to the
machinery room ventilation outlet.
As always, regional guidelines and standards should be consulted.
2.6.4 Ventilation
Refrigeration machinery rooms should be vented to the outside air by means of natural or
mechanical ventilation.
Free Air Movement
Ensure that free air movement can be achieved around all refrigerant-containing parts of
the system. Openings for outside air should be positioned such that short-circuiting does
not occur.
Mechanical Ventilation
Where the refrigerant charge of a single refrigerating circuit exceeds the mass in
Equation 2.5.3.a, a machinery room using DURACOOL® must employ mechanical
ventilation capable of providing the minimum ventilation rate. The minimum ventilation
rate depends upon the type of electrical protection within the machinery room. Where
the installation is protected according to Section 2.6.6 the mechanical ventilation rate
should be equivalent to at least 10-room volume changes per hour.
Duracool Refrigerants Inc. 15
