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o
The emergency exhaust ventilation fan shall:
▪
▪
▪
o
Airflow of the emergency mechanical ventilation shall be at least
where
o
Mechanical ventilation shall be operated continuously or shall be switched on by the detector.
•
Detector shall automatically activate an alarm, start mechanical ventilation, and stop the system when it
triggers.
•
The location of detectors shall be chosen in relation to the refrigerant and they shall be located where the
refrigerant from the leak will concentrate.
•
The positioning of the detector shall be done with due consideration of local airflow patterns, accounting for
location sources of ventilation and louvers. Consideration shall also be given to the possibility of mechanical
damage or contamination.
•
At least one detector shall be installed in each machinery room or the occupied space being considered and/or
at the lowest underground room for refrigerants heavier than air and at the highest point for refrigerants lighter
than air.
•
Detectors shall be continuously monitored for functioning. In the case of a detector failure, the emergency
sequence should be activated as if refrigerant had been detected.
•
The pre-set value for the refrigerant detector at 30 °C or 0 °C, whichever is more critical, shall be set to 25 % of
the LFL. The detector shall continue to activate at higher concentrations.
•
All electrical equipment (not only the refrigerating system) shall be selected to be suitable for use in the zones
identified in the risk assessment. Electrical equipment shall be deemed to comply with the requirements if the
electrical supply is isolated when the refrigerant concentration reaches 25 % of the lower flammable limit or
less.
•
Machinery rooms or special machinery rooms shall be clearly marked as such on the entrances to the room,
together with warning notices indicating that unauthorized persons shall not enter and that smoking, naked light
or flames are prohibited. The notices shall also state that, in the event of an emergency, only authorized
persons conversant with emergency procedures shall decide whether to enter the machinery room. Additionally,
warning notices shall be displayed prohibiting unauthorized operation of the system.
•
The owner / operator shall keep an updated logbook of the refrigerating system.
The optional leak detector supplied by DAE with the chiller should be used exclusively to
check refrigerant leakage from the chiller itself.
D-EIMWC01008-16_03EN - 10/35
Be either in the air flow with the motor outside the airflow or rated for hazardous areas
(according to the assessment).
Be located to avoid pressurization of the exhaust ductwork in the machinery room.
Not cause sparks to occur if it contacts the duct material.
V
is the air flow rate in m
m
is the mass of refrigerant charge, in kg, in the refrigerating system with
the largest charge, any part of which is located in the machinery room;
0,014
is a conversion factor.
Refrigerant LFL
R1234ze
0,303 kg/m
2
⁄
�� = 0,014 × ��
3
3
/s;
Pre-set alarm
3
3
0,07575 kg/m
16500 ppm
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