Retrotec Commercial 441 and 451 DucTester User Manual
Page 56
Page 56 of 56
©Retrotec Inc. 2015
Term
Definition
Pascal (Pa)
Often shown as “Pa”. A very small metric unit of pressure. There are 249 Pascals in 1 inch
Water Column (the pressure required to push water up 1 inch in a tube). One Pascal =
0.000145 psi.
Pressure Class
Duct pressure classifications are equivalent to Duct Class
Pressurization
The process of creating a positive pressure in the house by blowing air into the enclosure.
Air is pushed out through all the leaks, causing the smoke to move away from the operator
when checked with an air current tester.
Range Configuration
The plastic Range attachments on the Retrotec Fan. On the Model 400, Range
Configurations available are Ranges: 74, 47, 29, 18, 11, 7 and 3.
Reading
A set of simultaneous Room Pressure and Fan Pressure measurements. Sometimes referred
to as a data set or test point because it is plotted as one point on a graph.
Reference Pressure
The pressure at which the ELA is calculated, usually at the test pressure.
Water Gauge
See “in WC”