B&C Technologies FC-18 Fire Cabinet - Manual (Page 21)

21 © PODAB 2009
Evacuated amount of air and pressure fall
In order to get FC 18 to work properly, the ventilation channel
shall be designed to get an out coming air flow from the cabinet
of about 300 m³/h. When the cabinet is installed to an existing
channel system, the cabinet can be calibrated to optimize the
air flow.
In order to gain this air flow, the pressure fall must not exceed
210 Pa. By an airflow of 300 m³/h and a diameter of the pipe
of 160 mm, this corresponds to a straight, smooth ventilation
channel of 140 m.
Pressure fall estimation
The counter pressure in the ventilation channel can be mea-
sured with a pressure meter. The measuring point shall be
placed by the cabinets evacuating outlet.
In order to estimate the pressure fall without meter equipment
we recommend the following:
Identify the ventilation channel’s incoming components in the •
air flow direction.
Check the part pressure fall for each component in the table.
•
Calculate the total amount of pressure fall by adding each •
parts pressure fall.
The table shows the most common components in a ventilation
system. The information shall be considered as approximate
data. For more information, contact the manufacturer of the
parts of the system. Please note that the data in the table is for
an air flow of 300 m³/h.
Component Pressure fall
Circular channel ø, mm Pa/m
125 4,5
160 1,5
Pipe bends 90 º ø, mm r, mm Pa/bend
125 125 10
160 160 4
Reduction Transition, mm Pa/reduction
125 to 160 4
160 to 125 17
Example: 10 m long 160 mm channel with 3 pipe curves which gives an estimated
pressure fall of (6 x 1,5) + (3 x 4) = 21 Pa.
Increase the outgoing air flow
The drying cabinet gets its air from the small space between
the doors and the cabinet. An increased incoming air flow gives
automatically an increased outflow. The doors are kept in place
by two magnets, which both are assembled to a bracket. To
increase the incoming air flow, loosen the two screws on the
bracket and push it forward.
r
Ш
Ш
r
Ш
Ш
r
Ш
Ш
Decrease the outgoing air flow
The cabinets function and automatic programs are optimized
for the recommended air flow of 300 m3/h. If the design of the
ventilation is made so that evacuated air flow exceeds 300
m3/h, the evacuation can be throttled with help of a damper.
Contact a ventilation expert in order to find a proper solution
for your ventilation.