In The Field With Neil: Automatic Fan Control

Most of us use either the Energy Conservatory DG-700 or Retrotec DM-2 digital micromanometers.  These meters have some great, yet under utilized features.  I would like to introduce you to one of the features – automatic fan control.  The Energy Conservatory refers to it as “cruise control” and Retrotec as “set pressure”.  In either case, it allows the digital pressure meter to control the fan speed or flow based on the pressure of “A” channel.

With the Automated Control you can…

  • quickly measure building airtightness using a “one-point” 50 Pa test.
  • quickly measure duct airtightness using a “one-point” 25 Pa total leakage test.
  • simultaneously control both the blower door and duct tester fans during a leakage to outside duct airtightness test. During this test, the meter will maintain a constant 25 Pa building pressure while the gauge connected to the duct tester fan maintains a constant 0 Pa pressure in the duct system.
  • maintain a constant building pressure while pressure pan testing, or locating and sealing building and duct system air leaks.
  • perform series leakage to quantify leakage rates between various zones within a building.  (Check out our class on Advanced Pressure Diagnostics…we will be using the cruise control a lot)

So this sounds great – what do you need in order to use the automated fan control feature?

  • An “automated fan compatible” gauge. Most are, but check that it has either “EC-cruise” or “Retrotec-set pressure” buttons on the front panel of your digital pressure gauge.
  • A blower door or duct tester fan speed controller with proper communication jack.
  • A cable to connect the meter to the fan.

That is it!  And you probably already have everything you need – especially if you recently purchased your equipment.  So next time you are out in the field – give it a try; I know you will ask yourself, ‘how did I ever get along without this?’.

For more information on automated blower door control:

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