Retrotec Residential Pressure & Air Leakage - Manual (Page 23)

Page 23 of 75
4. Wait 20 seconds before taking note of the pressure reading on channel A (“PrA”). Record this value
directly into a software program, or on the sample test form to be entered into a software program
at a later date.
5. Wait another 20 seconds before taking the next reading, and put this value into the second yellow
box in the Bias Pressure row in the software.
6. Continue this process for as many bias pressure readings as the protocol requires (up to 12
individual readings).
7. Uncover the fan and employ the Flow Range that is believed to be the best one for the desired
building pressure. This can easily be changed: if the flow reads “TOO LOW” on the gauge switch to
a Flow Range with a smaller hole, or if the fan speed is too high, and the target pressure can’t be
reached, switch to a Flow Range with a larger hole.
8. Use the gauge or speed control knob to turn on the fan to reach the desired building pressure
(usually 50 Pa). Example: On the DM-2 gauge press [Set Pressure] [5] [0] [Enter]
9. Once the fan adjusts to the desired pressure, wait 20 seconds to record the “PrA” value (building
pressure), and record the fan pressure “Pr B”, with both readings in Pa. Make sure that the correct
Device and Flow Range are selected on the gauge, otherwise the results may be inaccurate. It may
be easier to record results with the Hold, @ Pressure, and/or Time Averaging features active (if
available).
10. Collect final bias pressures in the same fashion as was done in step 3. Make sure to put the fan back
to the position it must be in to follow the guidelines (i.e. covered, or on the L4 Flow Range). Record
the bias pressures.
3.6 Perform a Multi-Point Test
Some protocols require completion of a multi-point test in order to be in compliance with the standard. If this is
the case, a multi-point test can be completed either manually (with results recorded by hand from the gauge) or
automatically with a gauge connected to a computer. The following procedure details how to collect the data by
recording results from a digital gauge, with examples using the Retrotec DM-2 gauge.
1. Record the appropriate building and tester information on the sample test form provided in
Appendix B.
2. Set up the fan(s) to take bias pressures: this will normally be with the fan cover on, with the L4 Flow
Range set-up. However, it is recommended to follow the procedure set out by the standard for
which the test is being run.
3. For a multiple fan set-up, make sure all fans are covered, properly connected to their respective
gauges, and all gauges are visible to the tester.
4. To collect bias pressure readings, set the gauge(s) for 10s time averaging, and put them down on a
table, fan case, floor, or somewhere convenient. Wait 20 seconds before taking note of the
pressure reading on channel A, “PrA”. Record this value.
5. Wait another 20 seconds before taking the next reading, and continue in this way until all required
bias reading points have been collected.
6. Decide on the range of building pressures that will be required, and how many test points will be
taken. This will likely be defined in the protocol/standard being followed.
7. Determine the best Flow Range plate to use, in order to minimize Flow Range changes during the
test. You can test this by setting the pressure to both the low end and the high end of the selected
building pressure range. If the flow reads “TOO LOW” on the gauge, switch to a smaller Flow Range.
If the fan speed reaches 100% without reaching the desired pressure on Channel A, switch to a
larger Flow Range.
8. Uncover the fan(s) and attach the Range Ring or Plate believed to be the best one for the building
pressure being induced.
9. Use the gauge(s) to turn on the fan(s), in order to reach the first desired building pressure point.
Example: To begin testing at 10 Pa, press [Set Pressure] [1] [0] [Enter]