Extraction fan/Motor or whatever

[Don Nethercott]

What's this got to do with woodwork??? - I don't want to be gassed by my wife while doing my woodwork.

My wife does lampwork - that is - makes glass beads over a gas flame. Obviously a lot of waste gas. We have an extraction fan in the window but I don't think this is really sufficient. I want to run a 4 inch pipe from just above the lampwork, up through the ceiling and outside. However it needs a motor somewhere along the pipe to move the air. Something inline would be fine.

Does anyone have any bright ideas about what I could use and where I could get it. Remember I live in the bush so can't drop into my local Sydney store - will need to deal mail order.

Thanks
Don

[E. maculata]

G'day Don,
Try the tradies tool place near the train station in Grafton, they're always ready to look for stuff for me (eastland trade sup's) or Harold at Bnnings, he's alway fairly helpful with stuff.
(unusual disclamier stuff-no pecuniary interests etc etc blah blah....hang on, on second thoughts, our next door neighbour's Grandkids Mum runs the trade place and her kids & my kids are good friends, but that doesn't get me any freebies ) :D

[ozwinner]

Bunnies have cheap cooling fans, whack one in line blowing outside.


Al :)

[Cliff Rogers]

G'day

You'll get a kit with ann inline duct fan & some 6" flexible duct from the electrical wholesalers like Hayman's for about $140.

[Bob Willson]

You could take the fans out of an old computer power supply. Only problem is they would be 12 volt and you would need a plug pack to run them. Oh, and they are in a square shape

[glock40sw]

Why noy just use a bathroon exhaust fan above her work area?

We have one that has 2 heat lamps and a 60 watt light.:D .

Hooroo.
Regards, Trevor
Grafton

[Don Nethercott]

Thanks guys for the advice.
Good to see a few Grafton blokes (sometimes can't tell from the monica) on the forum.
I was hoping to get something with almost as much power as my Jet dust extractor (I've got the one that sits on top of a 44 gallon drum), although that may be a bit of overkll - but something that will really shift a lot of air.
Thanks
Don

[bsrlee]

Just remember - too much exhaust will cool the lampwork resulting in an unhappy wife :eek:

I've seen some 240 volt fans that look like computer fans, but you will probably only find them here in the 'Big Smoke'. Look for a fan with metal blades if you want to put it in-line with the exhaust gasses.

Another idea: run an old vacuum cleaner with the exhaust hose let into the exhaust pipe at a 'y' pointing away from the work area. An Old Acquaintance used such a setup in his blacksmith shop with part of the blast going to the fire & the surplus going to the chimney giving him a reasonably clean air environment.

[Gaza]

What about one of those kits used for sub floor ventalation, complete with motor and ducting. I think most plumbling supplies stock them.

[echnidna]

Why not just stick an extra fan in the window?
It will double the amount of air removed.

[Stuart]

Just thought I'd ask....are we talking about gas, ie flammable? In which case, is one where the motor is in the air stream really a good idea? (thinking spark, or arc, and big bang and all)

[ernknot]

Move the wife into her own shed!

[soundman]

One of those ducted fan kits would be the go. The fans are specificaly designed to go inline with pipe or hose.
See any electrical wholesaler.
I doubt that computer fans would moove anywhere enough air.
I expect the air stream would be cool enouhn not to present any problems.
I also expect all gasses would already be burnt.
You probably need some sort of hood to direct the suction.
one other solution would be to install a "good" ducted range hood.
All the stuff you need should be available from any electrical wholesaler.
cheers

[Waldo]

G'day Don,

You could go to Bunnies or Stratco and get one of those Whirlybird ventilators and put in on top of your shed roof, they are great for getting out any fumes and also suck out the hot air.

Otherwise a ventilation extraction fan into the side wall of your shed just near where your wife works, have one at one end of my bench and is great for sucking out paint fumes.

[Don Nethercott]

Thanks for all the advice.
Just for your info I got onto a US site that does glasswork and got this reply -

"You want to remove the air in the area around the torch in an aggressive way and from the entire room in a gentle manner. Most systems remove room air in an ok manner but not the air from the immediate work area. That said the design of the system is far more important that the amount of CFM. If the studio is 10'x10'x8' high you have 800 cubic feet that should be exhausted 3 or 4 times an hour. In addition you need a velocity of 100 feet per second flowing through the work area taking away combustion products and fume.

How do you do this? The cheapest way is to 1. Make the work area smaller by creating a cubical. A restaurant hood draws air from the entire room and you do not achieve the necessary velocity, but by dropping drapes on three sides it becomes much more efficient for drawing from a specific area. 2. The addition of a small intake vent (in the same system) at the top of the room will draw air from the entire room, which will remove fume that escaped the primary system.

For example we use 10,000 CFM fans to remove air under the hoods thru 20" duct. We have drapes on all four sides. The drapes go to the floor on three sides and within 6 inches on the forth. Above the hoods, near the ceiling we put a 3" hole to draw from the room. This removes any fume that may have escaped and is floating above the hoods. We change the air under the hoods 4 times a minute and in the plant 6 times an hour.

So, if you create a cubical for the work area that is 6x6x6 or 216 cubic feet your 88 cfm fan will change the air every 3 minutes (20 times an hour) and the room maybe every 15 to 20 minutes, but may not achieve the velocity you desire. A 4x4x4 box will perform even better. If the air flow by the torch will deflect a piece of tissue paper 1/2" wide by 6" long say 15 degree for a part timer or 45 degree for full time torch worker you have adequate ventilation. Keep in mind that no comprehensive study has been conducted to date. The 100 FPS velocity is drawn from OSHA and my experiments have indicated that this about a 45 degree deflection of the tissue paper."

Seeing as how the area I have to ventilate is approx 3600cu feet I need something that has a bit of suction. Think I'll use one of those underbench dust extractors from Carba-Tec - they are rated at 600cu ft/min. There is a mob in Sydney sell inline centrifugal fans that are rated around 1000cu ft/min but they are 250mm dia. Would it be possible to run a 250 dia fan through 100mm duct (that is the size of the hole through the brickwork, and the distance between the bearers and the floorboards (above).

Re some of you replies -
1) whirlybird no good as the workshop is under the house.
2) move the wife into her own shed - I've got 2 chances

Once again thanks for the suggestions - looks like I've got a big job ahead of me - but we'll get there.
Don

[glock40sw]

G'day Don.

Have a look at Supacheap in shopping world.
They have a fan mounted in a pipe.
its about a foot round and 18" long.
You would be able to punch it thru a wall no worries.
Hooroo.
Regards, Trevor
Grafton

[gatiep]

How about mounting an extractor or ceiling fan ( round ) inside an upside down 20 L paint tin with a hole in the bottom where you connect it to some big bore ducting, through the ceiling and roof, or out the window. It will be easy to suspend that over the work area from the ceiling and the tin an ceiling ( extractor ) fan should be easily available in the bush. Don't just vent the fumes into the ceiling as it will eventually settle into the other rooms of the house.

[SWR]

G'Day Donn,


I am a Broadcast Radio Engineer and I have seen a small, but quite powerful extractor fan for placement near soldering workstations (as the fumes can be quite irritating).

Both Farnell and RadioSpares (in Sydney) both sell these and they filter the air thru a carbon replaceable filter.

I figure that you could attach somehow, a 4" duct to the rear of these units and duct it out to the outside.

They run from about $250 odd and would probably do the job.

As I personally refuse to buy anything that I could make, I would check out these catalogues for the replacement filters, purchase a 240 volt fan and bung it all together myself for a hell of a lot less coin than these units would cost.

Donn, you could be equally handy and it would not be a big stretch to throw all of the components together...as long as you are comfortable working with 240v wiring....or failing that...use a 12 volt fan and purchase a 12 volt plug pack...all using a similar theme...

Some ideas for you...

On a related matter...and as I am pathalogically frugal....my place of work is building a new radio station on an existing floor and they had to strip out all of the old wiring and airconditioning stuff. One of the things that they were going to throw out was a 15" industrial air extractor.

I grabbed it and thought it would make for an excellent room filter. I purchased 2 20" X 20" X 2" pleated air filters from a filter supply house in Sydney ($15 each) and housed it in a plywood box, where basically it sucks air in at one end (thru a filter) and blows it back into the workshop (thru another filter). The fan unit moves so much air that i worked out that it changes the air in the workshop 12 times an hour.

Not only that but where previously, at the end of the day after a good day in the shed everything was covered in a fine layer of dust...now there wasn't.

I had made one of these units previously with 3 computer fans that did remove quite a lot of airborne dust. But it still left dust on a lot of horizontal surfaces.

And as that dust was more than likely making it's way into my lungs...now it's not.


So for those of you in the market for a workshop air filter unit and your handy with woodworking and electrical, you might want to try a similar thing - seek out your local air-con guys and suss out if they can liberate an old fan unit your way.

Hope this info helps you Donn (or anyone else).


Cheers,


Scott in Peakhurst