Air flow test box how to build

[vacuumdevil]

I keep seeing lots of people posting airflow test using boxes that are either cardboard and leek air or are square in create air turbulence.

So today with the help of some patreon supporters I went to home Depot and decided to build my own. It's round and should have minimum air turbulence.

I decided to use ABS pipe for its strength and price point.
used my 1960s Bridgeport to Mill it flat and then to make a 10x 5/8 hole.
Finish the whole thing up with weatherstrip around the edges.

I'm curious to see what the results are though I'm very much in questioning the anemometer meter I got off of eBay.

Curious what vacuumland thinks of all this?

 

[vacuumdevil]

For some reason the pictures didn't post.

 

[lesinutah]

Uh

I don't think an airflow cylinder will yield correct info. Cyclonic is circular air flow. If you have ever been in a shop with a vacuum through there air ducts. This is basically what you made. The cylinder hole is used to put anamometer.
Don't quote me since science isn't my best subject. If you ask a math question is better equipped. It's just my observation.
Les

 

[vacuumdevil]

@lesinutah Yes I have been in my shop with a dust collector see pictures of shop posted above. No this would not create a cyclone effect the geometry is wrong for that.

 

[huskyvacs]

I think it would be too rounded to get a definitive seal from nozzle to tube

You should copy the one VacLab already built. I asked him before several months ago and he said it was OK to do it, but you can ask him again if you want.

His works pretty good, and he seems to get pretty definitive results with it. Good luck!



I have seen people making similar things for vacuum-forming plastic hobby projects, nearly the exact same construction - so it seems like a similar concept - just going the opposite way when you are testing with vacuums.

https://s3.amazonaws.com/assets.flitetest.com/article_images/full/pic7-jpg_1412404560.jpg

https://cdn.instructables.com/F2A/ZJ4T/IQ2KKFAC/F2AZJ4TIQ2KKFAC.LARGE.jpg

 

[vacuumdevil]

@huskyvacs take a look at the pictures it's been machined flat on one side.

The square wood box from Vaclabs leeks and creates air turbulence.

Vaclabs flawed testing is exactly why I made my own.
Their previous threads of disgusting details the flaws in his testing. Not to mention his bogus Kirby repair videos. I really don't want to get into the merits of that on here.
Thank you for your input.

 

[lesinutah]

Flaws

If you ought a storage tote it wouldn't leak air.
You could get drywall the green celotex and simple and mud corners. I'm pretty sure there is no tape the drywall is thick. It varies from 1-4 inches thick. I don't care if Einstein tried to find fault in the celotex drywall. You can rest assure there would be no leaks. I'd say use solid wood but wood is a bad insulator( real wood not engineered.
I'm thinking it's okay in theory. Get some type of smoke and put into the tube. This should give you the idea of it's air tight.
I've put my anamometer directly under brush roll got for example a 142 141 CFM on eureka and sanitaire factory specs say 145 CFM.
I initially got highest rated anamometer off Amazon. It was DOA I bought second highest rated. I'd say it's very accurate.
If you get close on brush roll you can get CFM. You can argue accuracy but you eventually get ideal distance. You can say you lose CFM over a distance not giving correct CFM.
If you think a box is flawed under same reasoning anything except straight under brush roll or nozzle is potential for flaws.
I'm biased and I'm not saying anything about flaws in just stating logic that can be taken any way.
I think your cylinder test tube if no leaks would yield good results.
Les