Fan Question

stashia · #1 2009-01-14, 12:27pm

I know that there are hundreds of pages of info on ventilation and I think I've read every one at least twice but am still a little confused on what fan to buy. I will be building a portable barley box with a removable board attached to place in the window when I'm torching (funnel style vent) using 8" rigid ductwork with 1 bend (desk is right next to the window) makeup air coming from across the room (kitchen window). Will this fan work?

http://www.rockler.com/product.cfm?p...9&cookietest=1

Also will I have to wire it to electrical? Im not so good at that so is there something that I can buy that will plug in to a regular outlet and is ready to go.
Thank you in advance for your help.

Raven Wylder · #2 2009-01-14, 5:54pm

Stashia, I believe this is a booster fan - I couldn't find what the real cfm was based on the info on the site. I do not think this will work for you.

yellowbird · #3 2009-01-14, 5:57pm

No

stashia · #4 2009-01-14, 6:31pm

ok thank you, any recommendations for something that will not be super noisy?

Corey · #5 2009-01-14, 6:49pm

Can I ask why something like this wouldn't work?

NMLinda · #6 2009-01-14, 6:58pm

The free air CFM listed on the site is only 250 cfm. From what Stashia describes of her duct work, there is likely to be little static pressure, so the fan should deliver almost all of the 250 cfm.

If she's building a barley box with an opening similar to what others have done, she'll need anywhere from ~375 cfm to ~650 cfm, so this fan is under-powered for her needs

Linda

NMLinda · #7 2009-01-14, 7:00pm

Apppologize for a typo - the fan's rated free room air cfm is only 210 cfm. Too low....

yellowbird · #8 2009-01-14, 7:04pm

It is just not strong enough . Maryland Hydroponics sells in line can fans for about $200.00 they fit right into the pipe and you can get a control switch for another $25.00 or so..There is a lot of information in the safety section. They actually ship from California , if you look around on ebay you might be able to find one closer to where you live.

stashia · #9 2009-01-14, 7:26pm

thank you yellowbird, maybe something more like this
http://cgi.ebay.com/8-CAN-FAN-furnac...QQcmdZViewItem

Diane (clarus) · #10 2009-01-14, 9:15pm

No, that is also a duct booster fan, just like the previous one.

The seller wants you to think it's the same as the Can Fans they sell at the hydroponics suppliers, which IS what you want. As others have said, you need to figure out how big the opening of your Barley Box will be, then get a fan based on that. If I recall correctly, the basic calculation is the number of square feet opening (for instance, 3' wide by 2' high equals 6 square feet), then multiply that by 125. For that size you'd need a 750 CFM fan. I have a Vortex PowerFan that is 747 CFM and it works well and has a standard power cord that I plug in to turn it on. The newer Can Fans (the real inline blowers, not duct boosters) are supposed to work even better and are quieter. No fan of this kind of power is going to be silent - the fan isn't what makes the noise, it's the fast movement of the air that you hear. You can also get a squirrel cage fan, which makes a 90 degree bend - they work just as well (some say they work even better). Any fan you get in this class is going to be more expensive, but well worth it to keep yourself safe. You're asking the right questions, so keep asking until you're comfortable with getting your studio set up. Keep us posted.

-Diane

Raven Wylder · #11 2009-01-14, 9:46pm

Booster fans basically "boost" the cfm of a system (fan) already in place. Keep in mind that with lampworking you need to move a minimum of 125 cfms per square foot opening, like what Diane states above.

GlassyEyedGirl · #12 2009-01-15, 8:45am

Stashia, my setup is very similar to yours, and this is what I bought (see link below). It was very easy to mount into a piece of plywood that I can hang on the window while I torch. It does need to be wired into a plug, but this is REALLY simple to do. Just go to your local hardware store and get a cord, plug and some of those little cone shaped covers for the wire connections and voila, all set. Hey, if I can do it, anyone can! We have a very helpful local hardware store

I like the fact that it has lightweight shutters that open automatically when the fan is on too. I just leave it in the window most of the time. I wouldn't say it is the QUIETEST fan ever, but it is really not too bad. The cfms sound really high, but I am super-sensitive to the fumes and I did not want to take any chances. I thought it would suck the bead right off my mandrel, but it really does not seem like too much, nor does it affect my torch flame.

http://store.h-mac.com/tpishmodidre1.html

You are smart to stay safe! Good luck!

stashia · #13 2009-01-15, 10:18am

ok, thank you all so much for your help. I think I got it now. Something like this?
http://www.homegrown-hydroponics.com/vtx800l.html I will need to check the cfm's of course i dont really want a hood per se just a tabletop funnel type if that makes sense what can I use for that?

Diane (clarus) · #14 2009-01-15, 11:17am

You're getting there! That fan looks similar to mine, but it's got a lower CFM rating. Here's a link to one where you can get both the Vortex fans (mine is the 8" 747CFM one) and the good Can Fans:

http://www.mdhydro.com/inline-centrifugal-fans.html

These are less expensive than the site you mentioned.

Maybe someone else can chime in on any known calculations regarding a funnel type setup - I've been curious about them, but am concerned they're not as safe as a hood type of ventilation system.

Another excellent site for reading up on ventilation is:

http://mikeaurelius.wordpress.com/

-Diane

NMLinda · #15 2009-01-15, 11:25am

Stashia,

Funnel-type vents are completely different than the Barley Box. The latter is a fume-hood style venting system, and it doesn't sound like you will be doing that. For the fume-hood/barely box style, the Vortex fan you mention might be sufficient, just depends on your vent-hood opening. Dale M. has some good info posted on Art Glass Answers, as well as LE, on how to calculate the CFM's you need.

Like Diane, I'm also very interested in the funnel style, but also concerned about how to design them for sufficient venting. Bet they need way more fan power than 600 CFM. Does anyone know how to do the calculation and how effective they are vs the barely box/fume hood?

Linda

Dale M. · #16 2009-01-15, 11:49am

As far as I know at this time there is no real ratio/formula for calculating how many cfm is needed for funnel opening size....

I'm sort of betting anything under 500 cfm will be to small....

I wish some people would also chime in with their fan size and funnel/duct sizes and their result so we can form a consensus of how to construct a safe system ...

Dale

GlassyEyedGirl · #17 2009-01-15, 12:14pm

I actually have a Barley box type of setup. In case I did not make that clear in my first post

RuskinDesigns · #18 2009-01-15, 12:39pm

I have a 747cfm vortex fan with a 12" funnel opening and it will suck smoke to it from 4 ft away. If I hold the smoking item above the opening of the funnel it will suck it down. Only drawback is that it is noisey.

I got my fan from http://www.bghydro.com/BGH/itemdesc....AEFV08&eq=&Tp=

bead_your_habit · #19 2009-01-15, 1:17pm

Diane, thank you for posting the wesbsite: http://mikeaurelius.wordpress.com/. It answered many basic questions I had.

I'm left still wondering though..neither myself nor my husband have an ounce of ability in the "handiness" department nor do we know anyone who does. Is there a purchasable all-in-one ventilation system for a basement window that is just "plug and play?" so to speak? I found this one: http://www.glasscraftinc.com/product...m?part_id=7159. Do you think this could be sufficient?

stashia · #20 2009-01-15, 2:20pm

Everyone here is so helpful and I truly appreciate that. I think I have a good idea on the fan, just need to find one with more cfm's that's not super noisy.

One more question to some of the experts I have a gas line for a bbq in my back yard directly outside the window where my venting will be. Could i possibly use this as my gas supply? I will be using a cricket with M-10 concentrator. I was thinking that I could run a hose in through the window, is this safe? and would this be enough gas pressure?

Diane (clarus) · #21 2009-01-15, 3:08pm

Beadyourhabit - I wish there was a single place where you could buy a sufficient ventilation system! The one from Glasscraft that was linked in your post is a funnel system. There is no info on the page regarding CFM of the fan, but given their history of selling underpowered ventilation systems I'd stay away from them. If you do a search on Glasscraft in this forum you'll find lots of posts about it. Specifically, find Hayley's posts which have a lot of specific info regarding her experience with their hood. Their hood itself is fine, it's the fans that have been included that are the duct booster variety (see above), as opposed to an inline or squirrel cage fan which is designed as a primary medium to move a lot of air.

Also, with this system it includes flexible duct, which should not be used. It reduces the amount of air that flows through the duct. Please excuse my brain drain at the moment - I can't remember the exact reasons, but there is lots of info here in the forum about it. If I get a chance later I'll try to find the links to the posts that talk about it.

Plus, for $345 you can get a really nice inline or squirrel cage fan, and some ducting pieces at Home Depot or Lowes and build your own for a lot less!

Stashia, I started out on a Hot Head torch. They are loud by themselves. Everything I have running in my current setup is quieter than that torch alone - that's my ventilation and both of my oxygen concentrators! I used to have to have my iPod blasting to hear it over the torch alone, now it's at a reasonable volume without destroying my ears.

Regarding the gas line, Dale has some info on tapping into that gas line on his site that's linked in his post above. He has a wealth of information there.

-Diane

Raven Wylder · #22 2009-01-15, 5:58pm

Flexible ducting causes more air friction due to the ridges and affects the static pressure in the system which in turn affects (lowers) the cfms of your fan.

The gas lines can be run through the window if you attach and remove (and bleed) the hoses at every use. Quick connects can help with this. Legally can not leave the hoses through the window as a permanent set up. You'll need to get pipe fittings rated for gas and have an outside/inside turn off system for safety reasons. Dale has written on this somewhere in this room (safety) so you I'd recommend to search for it.

bead_your_habit · #23 2009-01-15, 6:00pm

Okay, thanks Diane. If I knew someone locally who had a clue to what the vent system should include and how to attach a fan to ductwork, I'd try building it myself, but with no local lampworking friends, if I want to be safe (and I do) I'll have to keep saving up and hope hire/befriend an HVAC specialist. Maybe I can barter my bod for ventilation - I'm not that bad lookin'! lol Thanks for your help!!!

NMLinda · #24 2009-01-15, 6:35pm

You might want to cruise past posts here in safety and over in Studio for ideas. Folks have posted pictures, which can give you a good visual. Some are elegant, and some are more how-can-I-do-this-cheap-easy that are no less functional and effective. Once you see systems a bunch of times, you might decide it's not as hard as you think

Good luch!
Linda

Diane (clarus) · #25 2009-01-15, 11:13pm

Regarding flexible ducting - thanks Sheryll! I'm not that old but sometimes I get a bad case of brain drain.

Putting together the ducting is easy - like putting together a puzzle made out of sheet metal. I fabricated my hood myself using sheets of steel from Home Depot and cut and formed it with metal shears and a small wire bender. I made it way too complicated to reproduce; I don't recommend trying! The easiest thing to do is build a box out of wood and line it with the steel. Then, get a part called a "reducer" that you can attach to the top of the box, and attach the ducting to that. I'd attach the steel to the box with screws or staples, but once you have the ducting attached to each other you can seal it up with foil tape - available in the ducting section. It really isn't that hard!

I wouldn't contact an HVAC specialist; most of them know nothing about ventilating noxious fumes like the torch/glass generate. If you can find one who does, you're fortunate.

-Diane

yellowbird · #26 2009-01-16, 6:27am

Equally as important as ventilation is make up air (coming in) from at least ten feet from exhaust .

szglassy · #27 2009-01-16, 7:54am

Check out the thread " funnel/guess the size" thread in the STUDIO area of this forum.

Sorry, I don't know how to link the thread.

It talks about funell sizes and a pic of Offilia's set up.

Hope this helps.

Dale M. · #28 2009-01-16, 10:38am

Quote:

Originally Posted by szglassy

Check out the thread " funnel/guess the size" thread in the STUDIO area of this forum.

Sorry, I don't know how to link the thread.

It talks about funell sizes and a pic of Offilia's set up.

Hope this helps.

But all that information means very little without size of blower/fan that is being used....

Dale