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D-EIMAC01706-18EN - 5/32
Machinery rooms shall have doors opening outward and sufficient in number to ensure freedom for persons to
escape in an emergency; the doors shall be tight fitting, self-closing and so designed that they can be opened
from inside (antipanic system).
Special machinery rooms where the refrigerant charge is above the practical limit for the volume of the room shall
have a door that either opens directly to the outside air or through a dedicated vestibule equipped with self-closing,
tight-fitting doors.
The ventilation of machinery rooms shall be sufficient both for normal operating conditions and emergencies.
Ventilation for normal operating conditions shall be in accordance with national regulations.
The emergency mechanical ventilation system shall be activated by a detector(s), located in the machinery room.
o
This ventilation system must be:
independent of any other ventilation system on the site.
provided with two independent emergency controls one located outside the machinery room,
and the other inside.
o
The emergency exhaust ventilation fan shall:
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.
o
Airflow of the emergency mechanical ventilation shall be at least:
𝑉 = 0,014 × 𝑚
2
3
⁄
where
V
is the air flow rate in m
3
/s;
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 It is a conversion factor.
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.
Refrigerant
LFL
Threshold level
R32
0.307 kg/m
3
0.7675 kg/m
3
36000 ppm
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