4 Installing the BlowerDoor Measurement System
40
January 2022
BlowerDoor Standard
Changing the flow rings
Each flow ring has an ideal measurement range (appendix B.2). When
automatically recording a series
of measurements
with TECTITE Express, the software will indicate a change of flow rings.
If the
aperture
of the flow ring
chosen during leakage detection
is too big
, you will reach a building
pressure of, for example, 50 Pa, but will remain below the measuring range for this ring. The building
envelope is more airtight than expected and you will have to insert a smaller ring.
If the
aperture of the flow ring
chosen
is too small
, you will not even reach the desired building
pressure differential of, for example, 50 Pa at full fan speed. In this case, the building envelope is less
airtight than expected and you will have to continue the measurement with the next biggest ring size.
Fig. 4.15
To
change the flow ring
, rotate the ring clips to remove a flow
ring. Insert the correct ring face-up (identifying letter facing up and
the flow nozzle pointing into the fan) and retighten the fastener
clips.
View of fan inlet
–
open fan, flow rings A, B, and C
Fig. 4.16
