Soldering station fume hood design

[Danmo]

TL;DR Summary

Measurement and elimination of back-draft through a fume hood

Good day all,

I am currently building a fume hood for a soldering station which will exhaust air to the outside world via filtration.

As I would like to maintain constant negative pressure inside the hood, even in the event of back-draft from outside due to inclement weather, or one too many air entry/exits in the building momentarily open, I am after some ideas on how I would implement an air pressure sensor within the fume hood to measure and/or alert when back-draft is present.

At a guess, I figure I would need a pressure sensor inside the hood and one outside the hood to measure the relative pressure difference.

My question is;

Would a 10kPa air pressure sensor both inside and out of the fume hood (inside the building) register the pressure difference for the specifications of this fan? I am trying to conceptualize the fact that the interior sensor will measure fan influenced air pressure and the exterior will simply be measuring atmospheric pressure.

Would something like this work?
https://www.mouser.com/ProductDetail/NXP-Semiconductors/MPX5010DP/?qs=N2XN0KY4UWXY1XQyQ71Xsg==Many thanks for a push in the right direction

 

[Baluncore]

You might do better monitoring the rate of airflow in the duct since that is what is important. The pressure difference will be more a function of the restriction of clean air to entering the building.

 

[Tom.G]

The easiest way is to use a backdraft damper.
https://images-na.ssl-images-amazon.com/images/I/41FMmlw8L6L._AC_SX425_.jpg

Those are two flaps in the pipe that are pivoted in the middle. The airflow pushes the flaps up, without airflow the flaps fall down to the closed position shown in the photo.

( photo found at: https://www.amazon.com/dp/B083M613K3/?tag=pfamazon01-20)

Cheers,
Tom