MANDÍK CPV Installation, commissioning, and maintenance
IZU 02/2021
MANDÍK, a.s., www.mandik.cz
R
25
Once differential pressure is measured [Pa], air output
/h
m
3
is calculated using the k-factor
for the given fan and the equations specified in the fan sticker.
Air output may also be calculated as follows:
Fig 10 Measurement instrument connection.
Equation for calculating air output
/h
m
3
.
k = k-factor (table above),
w
p
= measured pressure differential [Pa]
Fan speed is adjusted by changing fan output [%] to correct for any deviations between the
measured air output and the air output set point specified by the project (technical
specifications). Increased output = increased air output and vice versa.
All dampers must be in the maximum open position when changing settings.
If the required air output cannot be achieved, this indicates an inspection of the unit (internal
clogging, foreign local pressure resistances) or ductwork (foreign local pressure resistances,
design external pressure loss does not match the actually installed ductwork), etc. is
required.
An entry on the changes to unit settings must be recorded in the corresponding protocol.
The measured values are considered suitable if the deviation between the measured values
and the values in the technical specifications of the unit do not -10%.
Changes to air output must be conducted per the pressure conditions specified in the project
or by the type of operation inside the conditioned space: equalized pressure, positive-
pressure or negative-pressure ventilation.
The control protocol must specify the following information:
•
Identification of the equipment (order number, serial number, position in the project)
•
Details as to the person making control changes, including their signature and stamp
Fig 9 K-factors for open fan impellers Applies
for an air density of 1.2 kg/m3