Vane Anemometer

[barney_b]

Who uses one?
Has anyone ever used one in their home grow?

Cheers
B

[GEORGE]

Don't even know what that is. haha

[barney_b]

Don't even know what that is. haha

I had to Google it! It might be more for larger environments but it's basically a mini weather vane. Tells you have fast the air is moving.

With a handheld device, you could find dead spots in your tent or diagnose having too little airflow overall.

Cheers GEORGE
B

[scoot]

We use them at work to see if it's too windy for the cranes to operate,always wondered what they were called.

[MadJohn]

I've looked into these before for something unrelated.

I can't think of anything more tedious than spot checking all over the tent with something like this and I'm not convinced you could at all.

As airflow is so dependent on the seal and the tent configuration you can't have the door open or be inside the tent when you measure so that would mean some way of rigging it up static at known distances. Then you'd have to read it (not an issue with bt or wifi but that's expensive generally) and the second you move or nudge anything in the tent you're have to do it all over again. Or if your plant grew. Or cleaned anything. Or defoliated. You get the idea

I'm sure you've looked so I'm probably just making it up but considering so many people grow successfully with no fans I suspect you just don't need to be so precise. Happy if you know different though.

MJ

[Tommy stoner]

Can't you just look at the leaves and see if they are moving?

[barney_b]

I dunno. I've never even considered using something like this. Just curious if it was one of those, "oh yeah dude how else do you know if your fan is strong enough" moments. @MadJohn, makes sense about the tent. Must be for a room type situation. Probably overkill.

Cheers guys
B

[MadJohn]

I dunno. I've never even considered using something like this. Just curious if it was one of those, "oh yeah dude how else do you know if your fan is strong enough" moments. @MadJohn, makes sense about the tent. Must be for a room type situation. Probably overkill.

Cheers guys
B

If I were to take it a bit further.

If you have a large room and you have small directional fans that don't rotate it may be possible to check if it's reaching the corners using this approach. But the first question I'd ask is "what's enough air"? Air and air movement is pretty complex. CFD modelling might actually be the best approach to give a clearer idea but even that's a complex process. I found the following diagrams which illustrate doing CFD for a typical office with typical ventilation.



But they went further where they split the room into 3 levels, top, middle and bottom and came up with the following



Now offices and office rooms are very different in makeup to a grow room but I do think the second t/m/b view is very interesting from a visualization point of view. While I've got the software to do it, I don't have the knowledge to do it properly but it would be an interesting thing to play with and try and model for a typical tent. If you were really dedicated you could take a set of standard tents and work out optimal placement of fans based on their CFM rates. But I'll be honest I think that's more for fun than anything else.

For another view.

The UK has a fantastic set of building regulations and one of the "parts" is called "Ventilation: Approved Document F" or Part F as it's colloquially known. This goes into considerable detail regarding room, house and building ventilation and some detail on how to measure it along with recommended values. It's an interesting read but it might give some insight over what's "enough" and what isn't, at least on a room and building basis.


MJ