Frankola Posted March 23, 2016 Share Posted March 23, 2016 Hello,first post in a very good forum. Have read and searched for an idea of using a fan to extract the smoke out trough the wall. Can you use a Y type of pipe , one from the hood,one from the fan,to create a suction in the chimney? The fan will take air from another room. Quote Link to comment Share on other sites More sharing options...
Frosty Posted March 24, 2016 Share Posted March 24, 2016 Welcome aboard glad to have you. If you'll put your general location in the header you might be surprised how many of the IFI gang live within visiting distance. Playing this kind of game with stacks isn't for guys who don't know what they're doing so in short NO. That isn't going to work despite how many well meaning but less than knowledgeable guys will say it's a good idea and offer ideas of their own. Look into a side draft hood. Make sure your shop has enough make up air to support the stack's draft. Another little trick if the room's reasonably tight is to put a window fan in a window blowing INTO the room. This will pressurize it a little assisting the draft in the stack. But NO don't try coming up with some sort of forced exhaust system with a birds nest of stove pipe fittings. It's just NOT safe. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mark Ling Posted March 24, 2016 Share Posted March 24, 2016 a side draft forge hood works of of a draft (obviously) and so this is much safer and easier in ways. I am currently using a super sucker side draft forge hood. it works great!! as long as their isn't to bad of a breeze. I got the plans off of anvilfire.com anvil fire had a very good diagram with all of the measurements needed to make it. their is also many other blueprints for lots more projects. Littleblacksmith Quote Link to comment Share on other sites More sharing options...
Kevin Olson Posted March 24, 2016 Share Posted March 24, 2016 I tried the forced fan exhaust I have a 8 inch stack and installed a 4 inch elbow in it just above the super sucker hood that would blow straight up inside the stack. I hooked up a fan from a clothes dryer to it. The fan blows like crazy. I thought it would create a low pressure inside the hood drawing smoke into it. It kinda worked but results were disappointing. I removed it,plugged the hole and it works even better now. And yes, I had a door open for makeup air too. The idea of forcing air into the work space would have to work because the air going in has to go out the path of least resistance(chimney) Quote Link to comment Share on other sites More sharing options...
SReynolds Posted March 24, 2016 Share Posted March 24, 2016 Yes. This unit does.It almost works too. This is the result of what can be accomplished with unlimited funds. Built for the state of Ohio Historical society where I work. The three 90° bends in the flue tile are the latest thing. It is an authentic 1850's era blacksmith shop. Including the electric fan well hidden inside the chimney. Quote Link to comment Share on other sites More sharing options...
Mark Ling Posted March 24, 2016 Share Posted March 24, 2016 is that the shop you use? I really like the older original smithys! Littleblacksmith Quote Link to comment Share on other sites More sharing options...
SReynolds Posted March 25, 2016 Share Posted March 25, 2016 Sir. Yes sir. It is. Ohio Historical society. More or less. Not the village in Columbus. Rather the one near Canton. It is new(er) but the village is original from 1817. Some buildings are rebuilt. Gotta wonder who built this forge chimney. Real real bad. A professional no less. And the ji-normous hood ! Which serves no other perpous than to direct the ash onto your head. The other forge with champion 400 blower is on other side of the chimney. The stone forge employs a bellows. Interpretation is what I do. And teach classes . The funniest aspect is they rebuild the shop just like original per the photographs. But the forge and chimney? Even with pictures they decided to build it completely different. Smoke is a serious problem so I do my best to operate the internal fan and burn a hot fire with water on the green coal. The coke burns clean. Lots of open windows and the roof is also well vented via a very large coupla. Most folks don't complain. But there are always a few. Quote Link to comment Share on other sites More sharing options...
Frankola Posted March 29, 2016 Author Share Posted March 29, 2016 Thank you for all the replys . Forgot to mention that i can not have a regular chimney,but out of sidewall aproximitly 2 meter above the forge. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 29, 2016 Share Posted March 29, 2016 Most likely a "professional" bricklayer but not a professional chimney builder! Of course a good design could be overruled by the folks in charge---the blacksmith's shop at the village in Columbus was horribly built too; the way they mounted the bellows resulted in shoulder damage for the smith. My double lunged bellows I could pump to welding heat with my pinkie---theirs you had to wrap the strap around your arm and heave down on it with your weight just to use it for a regular fire. (ask Paul Ailing about sometimes at Quad-State) Quote Link to comment Share on other sites More sharing options...
SReynolds Posted April 4, 2016 Share Posted April 4, 2016 I fired the big forge this past weekend for first time in five months. It worked well with the draft fan on. It was pretty cool @ 42°F and had doors closed. Opened one window. The only time there is smoke is when I push fresh coke into the fire. The green coal I apply surrounding the fire smokes a little. Normally I don't operate the draft fan except while I start the forge fire. With Windows and doors open, the place clears out most smoke if there is any. Fourty foot ceilings and vented coupla help I'm sure. If you don't fire the forge properly such as with students and it's cold with doors closed then smoke gets pretty bad even with a draft fan on full tilt (super suck mode) Quote Link to comment Share on other sites More sharing options...
gote Posted April 6, 2016 Share Posted April 6, 2016 Frankola, Take a look at the thread 'Flashing around the chimney' At the end you will find my setup. It works very well with a horizontal "Chimney" Quote Link to comment Share on other sites More sharing options...
bustedknuckles Posted April 20, 2016 Share Posted April 20, 2016 I want to use a fan to power exhaust the air under my forge hood. While my experiments to date have been somewhat successful, I am looking for improvements. Has anyone done this successfully? I would very much like too hear how you did it. Quote Link to comment Share on other sites More sharing options...
Latticino Posted April 21, 2016 Share Posted April 21, 2016 I have not specifically power exhausted a forge hood, but I kind of do that sort of design stuff for a living. I have also power exhausted a hood over various glass equipment that essentially acts similarly to a forge in any case. My recommendations for full updraft capture would be to construct a hood that covers the entire heat producing area with approximately a 6" overhang on all sides. A capture velocity of approximately 100 CFM per square foot of hood opening will take care of virtually anything the forge can throw out. Your duct to the fan and building exterior should be sized for between 1,000 and 2,000 feet per minute of air velocity and the fan external static pressure be in the range between 1/2" and 3/4" water gauge (provided your duct routing doesn't go too far or have too many bends). I suggest an inline centrifugal fan with the motor out of the airstream. Make sure you obey any code requirements for the exhaust outlet location from your building and remember that you need to provide a source for makeup air to replace that which is being exhausted. A great sourcebook for additional information is "Industrial Ventilation" (check for copies in your local engineering college library). Quote Link to comment Share on other sites More sharing options...
Charles R. Stevens Posted April 21, 2016 Share Posted April 21, 2016 Scary what kind of experts we have here isn't it? Lol for solid fuel forges I have also seen exes air from an electric blower directed up the flue to improve draft Quote Link to comment Share on other sites More sharing options...
bustedknuckles Posted April 21, 2016 Share Posted April 21, 2016 I have never seen, nor have any idea where to get, an in-line fan with an external motor. I am familiar with a furnace blower, but the air intake is on the side, not in line. I probably could make one, but I would rather buy if possible. Any clues where one might look for such an animal? Quote Link to comment Share on other sites More sharing options...
Michael Cochran Posted April 21, 2016 Share Posted April 21, 2016 I could be wrong but I do believe a furnace blower is a centrifugal fan. As far as the inline part, if you hook the exhaust from your hood to the side of the blower it'll pull the air and then it blows the exhaust out the end into the next piece of pipe. Quote Link to comment Share on other sites More sharing options...
Latticino Posted April 21, 2016 Share Posted April 21, 2016 Apologies if I'm overcomplicating this for you. You can certainly jury rig something together that will work, particularly if you are only using the fan for some kind of boosting of the typical exhaust that you will get anyway due to the chimney effect. I was just trying to help with a design that I would make for myself if I was trying to ensure forced capture of everything generated by the forge. As far as an inline centrifugal fan, with the motor out of the airstream, the unit on the left is an example of that and the one next to it a similar fan with a direct drive motor in the airstream (the reason to keep the motor out of the airstream is to avoid having it damaged by heat or debris : There are any number of suppliers for this kind of equipment. Greenheck and Loren Cook come to mind immediately as reputable manufacturers, but you could always keep an eye out at a liquidator. Other possibilities include upblast rooftop fans, or inline fans with motor in airstream (if you have enough room air induced at the hood to cool the airstream adequately): Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted April 21, 2016 Share Posted April 21, 2016 The system I tried that ran the air around the motor tended to overheat the motor in the summer, using the air to induce a draft would probably work better. Quote Link to comment Share on other sites More sharing options...
Latticino Posted April 21, 2016 Share Posted April 21, 2016 2 hours ago, latticino said: A capture velocity of approximately 100 CFM per square foot of hood opening will take care of virtually anything the forge can throw out. Again I have to apologize, I wrote this too fast. Needless to say I meant a capture velocity of 100 feet per minute not CFM. Quote Link to comment Share on other sites More sharing options...
bustedknuckles Posted April 21, 2016 Share Posted April 21, 2016 You folks have been MOST helpful, and I really appreciate the input! Quote Link to comment Share on other sites More sharing options...
gote Posted April 21, 2016 Share Posted April 21, 2016 take a look at the thread Flashing around the chimney below This is cheap, simple and works. Quote Link to comment Share on other sites More sharing options...
bustedknuckles Posted April 21, 2016 Share Posted April 21, 2016 I LIKE it! Thanks! I even happen to have a blower handy...... Quote Link to comment Share on other sites More sharing options...
Frankola Posted June 28, 2017 Author Share Posted June 28, 2017 On 21. april 2016 at 11:16 AM, gote said: take a look at the thread Flashing around the chimney below This is cheap, simple and works. This is exactly what i was thinking of. Thumbs up....Thank you ,gote Quote Link to comment Share on other sites More sharing options...
KJC Posted July 20, 2017 Share Posted July 20, 2017 Take a trip to some HVAC shops. A lot of older furnaces that are being replaced have working fans in them. Some of those fans will have a belt drive and keep the motor itself out of the air stream. Even if the motor itself is shot the squirrel cage fan is there yet. Put on a new motor. Nice part about these fans is they have serviceable bearings. Move a lot of air and most HVAC places will sell 'em for scrap price. Quote Link to comment Share on other sites More sharing options...
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