Air Flow Hood Considerations w/ Dwyer

Jaden Lane joins us to discuss some best practices when using an air flow hood. She also explains how the Dwyer Smart is innovating in the hood space.

An air flow hood is an excellent tool, but we can't just assume that it'll work correctly in any system. Various vents and diffusers can cause different flow patterns to reach the hood, so you can get an incorrect reading if the flow hood is not aware of the flow pattern. Unless we give the hood background on what's going on in the duct, there's no way the hood will know the correction factor to give you the correct reading for the conditions in the duct. You can adjust smart flow hoods to compensate for inaccuracy factors.

Hoods are like big canvas skirts that you place over a vent, and there's a flow grid at the bottom. As air moves through the hood, the grid takes airflow readings. There are pitot arrays that act as traverse points on a duct traverse; these arrays take multiple measurements and give you an average. These devices work better when the air is a bit turbulent. If you doubt your measurement, you can also try the hood in different 90-degree orientations (but keep it centered).

Dwyer does a lot more than just make test instruments. They have a rigorous testing process for their products; their products can also work as permanent installations within buildings, not just tools for technicians.

Jaden and Bryan also discuss:

  • Dwyer products, including the Magnehelic
  • Vent vs. grille vs. register vs. diffuser
  • Computational fluid dynamic analysis and other test methods
  • Calibration vs. zeroing
  • Predictive balancing
  • Choke and backpressure
  • Vane and hot-wire anemometers

Check out Dwyer at

Learn more about Refrigeration Technologies HERE.

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