Airbrush spray booth

[PaulinKendal]

Benchvent 300SD recently purchased here, and I absolutely love it. Robustly built, quiet, effective at eliminating nasty smells and a sensible size (doesn't feel like you're spraying into a shoebox). Having said that, I do occasionally find myself forgetting to switch it on before I start spraying - operator error is always a potential hazard!

[Jim R]

That is what I've just ordered. Very glad to hear that you're happy with yours Paul.

[Guest]

Agree with everything written regarding carbon filters. I operated ours in a clean room environment so atmospheric contamination would have been far better controlled, leading to better operational life cycles. I never took that into account.

I would also say that it’s your lungs, you protect them as you see fit. I’ve just typed this up as it may be of interest to some.

Those particulate filter change times are simply outrageous. To me that means one of two things. Either the filters are not correctly sized so they are quickly overloaded, or (cynical view) the company has decided that overselling consumables is a way to supplement income.

A HEPA filter is not a sieve (common misconception), it is a maze. I attended several (five I think) courses run by Pall filtration in the course of my Pharmaceutical production career, and they used very good graphics illustrating this concept.

To summarise, the depth of filtration material to be crossed is what makes a particulate filter effective. The particles drawn in by the air have to navigate labyrinthine pathways as the air crosses the matrix, and eventually, due to the many changes of direction they are subject to, become impacted on the filter wall and are removed from the airstream. As more particles are impacted, the “maze” becomes more involved, so removing particles more effectively.

There are three ways you can get particulate breakthrough in this type of application. The first is mechanical failure of the filter matrix. The second is by the contaminant challenge at one time being too great for the filtration matrix’s ability to remove particulates, and the third is that the challenge partials are too fine for the filter to remove them all so they are carried through on the airstream. The first is eliminated by use of quality components. The others are eliminated by utilising a HEPA filter that has been appropriately sized for the task in hand.

With use a HEPA filter becomes more effective at its primary task, removing particulates. However, as it becomes more efficient at removing particulates, the airflow velocity drops off until it is lower than an effective threshold so rendering the filtration device ineffective. This is when the filter needs to be replaced.

Here’s some background.……My reasons for attending these filtration courses was to enable me to fully understand the concepts involved in worker protection and the design, installation, testing, and maintenance of bio containment equipment. This equipment included protected powder discharge systems and biological laminar flow safety cabinets.

These systems were velocity airflow tested daily, and smoke tested (particulate challenge) at three monthly intervals. No HEPA in my experience had a life of less than two years, and most of these systems ran 24/7/365. I realise that nobody on this forum has the ability to do this at home, but it is the most reliable measurement of filtration efficacy. If you do want to investigate this further, airspeed velocity meters are cheaply available on Amazon…..

However, my experience and knowledge tells me that In infrequent home use a filter in this sort of application should have a much greater life than two months……the HEPA should easily outlast the carbon filter.

I’m just surprised at how much particulate makes it past my MERV12 filter in my booth. The inside of my vent hose has color on it, along with the fan blades, and so does the window screen it exits through to the outside.

[Ian M]

All very good reading this and lots learned and more to be learnt. Dashed off to find where and for how much a Benchvent 300SD could be purchased.
WHAT? HOW MUCH?! Darn and gosh. Plus the Danish VAT then the import duties.... I need to lay down.

[BarryW]

All very good reading this and lots learned and more to be learnt. Dashed off to find where and for how much a Benchvent 300SD could be purchased.
WHAT? HOW MUCH?! Darn and gosh. Plus the Danish VAT then the import duties.... I need to lay down.

LOL yes, it’s not cheap but, for me unable to wear a mask and using lacquer based paint, it’s a worthwhile expense!

[Guest]

All very good reading this and lots learned and more to be learnt. Dashed off to find where and for how much a Benchvent 300SD could be purchased.
WHAT? HOW MUCH?! Darn and gosh. Plus the Danish VAT then the import duties.... I need to lay down.

That booth is only 208cfm??? That’s some pretty mediocre airflow for the price.

[Jim R]

The airflow is more than adequate for any airbrush work I will do. It's like so many things in life - "If you want something and can afford it then buy it. If it's not what you want or you can't afford it then don't buy it". For example are Wingnut Wings kits worth the high cost? Some modellers say 'yes' some say 'no'.

[Guest]

The airflow is more than adequate for any airbrush work I will do. It's like so many things in life - "If you want something and can afford it then buy it. If it's not what you want or you can't afford it then don't buy it". For example are Wingnut Wings kits worth the high cost? Some modellers say 'yes' some say 'no'.

Quality can be subjective. A measured airflow rating is not. That booth flows less than a $180 Amazon unit. But hey, it’s better than no booth at all I guess.

[Allen Dewire]

So true Jim!!! I say yes to the WnW issue, if the price is right......I too am looking into a new booth and your Benchvent was my first choice. They are hard to come by here in Germany and I did find one company that sold them. €497.00 delivered, but they didn't have any in stock...

Prost
Allen

[Tim Marlow]

Quality can be subjective. A measured airflow rating is not. That booth flows less than a $180 Amazon unit. But hey, it’s better than no booth at all I guess.

That’s not a measured airflow (mass flow) though Colin, it’s just a total volume measurement. Mass flow is measured in mass/time units, usually Kg/s.

Whats most important in this context is air velocity at the user face. This is measured in length/time units, like feet per second. To be most effective air velocity needs to be as even as possible across the entire face of the booth. This means no areas of the booth are not doing their job.

It is no good having a booth fan that can move huge amounts of air if it is only moving it from one spot. The rest of the booth will then have dead air areas and not collect contaminants. Unfortunately you can’t tell this without seeing one in operation and actually measuring it. I would say a higher quality unit is more likely to achieve this though.

[Jim R]

That booth is only 208cfm???

I don't understand what all the facts and figures mean but I can't find that figure in the specifications. All I can find is something which says ..
Air Volume 355m2/hr
[HEADING=2]Specification[/HEADING]

BV300S-D	230V 50Hz 105W	355 m3/hr	0.60m/sec	0.55m/sec	58

[Ian M]

That booth is only 208cfm??? That’s some pretty mediocre airflow for the price.

208cfm or cubic foot per minute is about 353m3 per hour

[Tim Marlow]

208cfm or cubic foot per minute is about 353m3 per hour

Another way to look at it is this:
If your room is about ten foot square and eight foot high it will pull all the air from the room through the booth in less than four minutes……not too shabby really.

[Ian M]

I have been looking at this one:

https://airbrush-shop.dk/udsugning/3397-airbrush-sprojtekabine-e550.html

Sou ds OK but 'only' 9m3 per minute lol that's 504 m3 per hour. I think that should be up to a bit of over spray.

[Tim Marlow]

I have been looking at this one:

https://airbrush-shop.dk/udsugning/3397-airbrush-sprojtekabine-e550.html

Sou ds OK but 'only' 9m3 per minute lol that's 504 m3 per hour. I think that should be up to a bit of over spray.

If you leave the windows and door shut that would pull up your carpet LOL….I’ve seen an extract fan pull the plasterboard off the walls in a clean room when the inlet fan failed, by the way