Retrotec Blower Door - Manual (Page 60)

Page 60 of 87
©Retrotec Inc. 2015
Appendix B: Find correct CFM at particular fan pressure
Flow conversion tables can be used to determine correct flow (CFM) at a particular fan pressure (Pa) on PrB. Back
pressure should be considered, especially if fan flow is going toward the operator (i.e. when the operator is in the
pressurized zone). The DM-2 gauge and the Retrotec self-referencing fans automatically measure back pressure.
The following five tables offer flow data for these situations:
back pressure of 10 Pa for 1000/2000/3000 fans, flow away and toward
back pressure of 50 Pa for 1000/2000/3000 fans, flow away and toward
back pressure of 25 Pa for DU200 fans
Back pressure has the biggest impact when flow is toward the operator, regardless of test direction.