Ventilation Complete - Check it out!
 

I have one of these
http://www.homedepot.com/webapp/wcs/...ctId=100088166
1600 CFM's

hooked up to some ducting exhausting out the window.



I know 1600 is moving a lot of air but is the ducting to far away from my face and working area? Do you need a hood to have proper ventilation?

Give me some feed back? I'm just a dumb guy with a big torch...

You need a hood...... 1600cfm means nothing if system does not have good capture area (hood)... Also what is your make up air source?...

Quite frankly my opinion is that, that fan is probably one of the worst you could choose for powered ventilation.........

Dale

I have an open window in another room. I realize I need a hood. Why do you dislike the fan?

Its big, inefficient and rating of fan is questionable.... I prefer centrifugal blowers that have motor out side hot air stream......

Propeller fans are for applications where its only necessary to make some air movement.... Its good to remove warm air from attic but I would not trust my health on it....

Dale

need hood and side walls...or else the air will be pulled from all directions. you want it directed past you, across the torch and out.

can you link me to some better fans/hoods for sale and maybe some diagrams of good ventilation systems that I could apply to my current schema.

here is one at the same store that will work great. i have been using one of these on my lampworking hood for quite a while. i used some duct adaptors to get a round duct on both sides of the fan.

http://www.homedepot.com/webapp/wcs/...3&ddkey=Search

any other input? I've switched ends of my workbench now so that I'm closer to the window and I can create a hood that will go right out to the window. What do you guys thinks is the appropriate size hood for a gtt mirage?

I would be interested in this as well, I was just about to purchase me exhaust system, but I didn't know I needed a hood, does anyone have any pictures that would illustrate how that would work with a fan system such as above?

here are some photos showing how to use the fan i suggested. i made my ventilation hood using a similar fan (it is the blue fan mounted on top of my hood, almost the same as the yellow stanley fan i linked to). i bought the cheapest hood if could find, got rid of the wimppy fan it came with, drilled a big hole in the top where i mounted the inlet to the fan, and then used some retanuglar to round duct adaptors to get the output into the duct to the outside. then i used cement wallboard to box in the sides and back of the hood so that i get more effective ventilation as well as a nice fireproof surounding. here is a link.

http://www.lampworketc.com/forums/sh...ad.php?t=67463

hey dale,

hey do you mind talking via email about proper ventilation. I just want to be safe and I had a nose bleed the other night. I haven't blown glass since and I'm going to rework everything and was hoping to utilize your advice.

There has been thousands of words written in dozens of threads on many boards........ I doubt I can say anything that has not already been said...

Dale

Am I on to something here or should I totally rework this? I bought an ecco or echo or eco or something 800 cfm fan. MY hoot is going to be somewhere in the ballpark of 900 sq in so 6.5 sq ft which comes out between 750 - 900 recommended cfm by your calculations dale... Am I right?

I'm worried now that the fan will get to hot what do you think?




I'm thinking this is a vast improvement... critique please :)

Conceptually you are going in righ direction... More pictures as you progress... Remember its the functionality of hood that is important...

Actually the width/height comes closer to 720 sq-in ( 24x30 =720)
So that is divided by 144 to get 5 sq ft ( 720/144=5)

5 sqft multiplied by 125cfm, (per sqft -standard) is 625cfm..

With fan you have selected it looks like you are on track...

You could move fan to window where air has cooled somewhat and connect from hood to fan with duct.. There no rules that says fan has to be at hood, it just has to be in "system".

Dale

I'd like some pointers and suggestions please or things I should absolutely *not* do?

Is it bad to use galvanized sheet metal or tin or any of the metals I'm using as a barrier? Will they possibly get to hot and cause damage or let off gases that will be harmful?

Will taping the seams with the foil tape work well to make the hood air tight? Or will that stuff burn right off?

If hood gets hot enough to off gas (from galvanized sheet metal) or melt you foil tape, something is definitely wrong.... Galvanized or tin plate is metal of choice for almost all ventilation work....

Just make it airtight and then test your work...

Yes surfaces will get warm but probably not so hot you can lay hand on it and keep it there while fan and torch are in operation ..

Dale

What is the best way to test the ventilation? I did some searches and couldn't come up with anything good. Care to share?

The first test would be to roll up some paper towels tight and light one end on fire then blow it out. This produces a nice amount of smoke to test with. I used some metal clamps to hold a smoldering towels in the possitions of each torch on the bench and sat and watched what happened to the smoke.

Is there any benefit to where the fan is attached to the hood for removing air? Like the back middle, middle middle, back left. any performance issues like that?

Well here it is... pretty much done with the bench, with exception to a few upgrades that I'd want to make. Mainly upgrade the seal on the ventilation ducting to the window. Right now its a plywood board with a hole in it. I'd like to make something with a better seal.

Vent system test
 

There is a test suggested on another board that is similar to the smoking paper test.
Fire up the torch as you would be using it.
Sit or stand where you would normally be.
Burn a small piece of bacon in the flame.
If you can smell any bacon smell it's not good enough.
PJH

No comments eh? Really?

This is an awesome hood! I recently made a vent hood as well and was worried about the heat transfer from the torch but I fired it up tonight and there was no problem! Although the flame does get fairly close to the galvanized metal on the top of the hood, it didn't get broiling hot - just warm to the touch.

I love the way your torch is INSIDE this vent - no hope of fumes escaping there!

Great job. Let us know how it works for you...

The hood itself is fantastic!

I do have a question about where the fumes go when they exit the system? And where is your make up air?

-Diane

The fumes are going out the window and into the sky. I have a room, 3 rooms down, (45 - 50ft) with a window open and all doors open on their way back to my room.

I understand that the fumes are being vented outside - what I'm curious about is if the exit port of the ducting is surrounded by anything, or if it is just blowing out an open window. It's hard to see what's going on with the closed blinds over the window.

-Diane

For system to work effectively window needs to be sealed against blowback ( gases coming back in around end of duct)...

Its easy to do.... have a piece of acrylic or ply wood or whatever with holes in it for duct... Put it in place during "work" time, remove it when done, just be sure it "seals".. Foam weather stripping tape does a wonderful thing here...

Dale

Dale - that's exactly what I was concerned about. Thank you for putting it into words for me.

-Diane

Well I have a piece of ply that the vent fits through pretty snugly and then i use a piece of 2x4 to put pressure on the wood so it stays snug. It's not perfect but that's my next improvement.

I'm in the process of buying a house so I can make things more permanent and not have to hide things from the land lord! :hide:

Sounds like a great plan! Thanks for clarifying this.

-Diane