samw1 Posted December 21, 2013 Share Posted December 21, 2013 Hi all, I need some advice, I get to much smoke in my shop and need a solution. I have a photo of my idea, it consists of a 2 ft shop fan with a funnel and piping of some sort, blowing air at an upwards angle hopefully adding suction to the chimney. Let me know what you all think. Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted December 21, 2013 Share Posted December 21, 2013 I can only guess so many things: Wot is the fuel? how big is the chimney? how tall is the chimney? How far above the roof does the chimney go? Is there anything near that chimney taller than it? Trees..other rooflines etc? Is there a way air can enter the shop in volumes equal to wot you want to exit the chimney? Fill in the blanks for help here? Quote Link to comment Share on other sites More sharing options...
samw1 Posted December 21, 2013 Author Share Posted December 21, 2013 10 inch 14 ft tall, it's heavy pipe so can only go so high about 5 feet above roof. Yes there are obstruction, with no eliminating them, usually opening the doors helps but with it being so cold I would like to avoid that. Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted December 21, 2013 Share Posted December 21, 2013 You have to have air in or air will not go out.....even if you put in a fan... Quote Link to comment Share on other sites More sharing options...
VaughnT Posted December 21, 2013 Share Posted December 21, 2013 How big is the opening at the fire? Generally, you want the opening at the fire to be no bigger than the cross section of the pipe, somewhat smaller is usually better. If you don't have air coming in to the shop, cold as it might be outside, there's nothing to replace the air that wants to leave up the chimney. Think about it like trying to suck through a straw.... if you put your finger over the end of the straw, restricting the flow in, you can't get anything out of the other end just like when the ice cream clogs the straw in your milkshake? Quote Link to comment Share on other sites More sharing options...
BobL Posted December 22, 2013 Share Posted December 22, 2013 Some photos of your setup would allow folks to provide better advice. By a 2ft shop fan, I assume this is some sort of a axial or propeller type fan? If so, these fans cannot generate much pressure and so are poorly suited at moving air along any ducting that is substantially narrower than their propeller diameter. What would be better is a fan that can generate a reasonable pressure in a narrow duct such as an impeller type fan that is used in dust extractors. Whatever you do, if you don't have enough air coming into your shop this is going to cause a problem. Also I notice a lot of folks don't always take preferred wind direction into account. If a shop that is exposed and the preferred weather/wind side comes from the opposite side to the usual opening into the shop this can suck air out of the opening which will reduce chimney draw. Quote Link to comment Share on other sites More sharing options...
wana be Posted December 22, 2013 Share Posted December 22, 2013 I started with a different problem the constant hum of the blower was annoying, so I mounted it outside the shop in a weather proof cabinet solved the noise problem also always have fresh air to the tuyere & don't have to worry about depleting my shop oxygen & I also think chimney draws better. John Quote Link to comment Share on other sites More sharing options...
Jim Coke Posted December 22, 2013 Share Posted December 22, 2013 Greetings, Just an Idea I came up with a few years ago..... You must have air coming into the shop to move it out as the boys said... I designed this to induce air when I add green coal ... Nothing more that an air jet to induce a draft... I use it sometimes on first start up... It is no substitute for a well designed forge air flow system... A small flip up shutter works well to help the draft.. No heat up the stack means smoke in the shop... That's my 2c.. Forge on and make beautiful things. Jim Quote Link to comment Share on other sites More sharing options...
LastRonin Posted December 22, 2013 Share Posted December 22, 2013 Wow Jim... Those are the whitest walls I've seen in any smithy I have had the chance to see. :) Nice looking shop and setup. And please enlighten a novice here... the neat looking vice on the left edge... what is it? Not a typical post vice is it? Quote Link to comment Share on other sites More sharing options...
Jim Coke Posted December 22, 2013 Share Posted December 22, 2013 Greetings Robin, I don't mean to misdirect this thread ... The vise is a caulking vise use for horseshoes and upsetting .. I am proud of this my smallest studio .. This is one I use in the winter and a teaching studio in the summer months.. I named it Studio FE 26... As you can tell I have been at this for a while.. The big blacksmith shop I close down for the winter ... Just to hard to keep it heated and plow the snow... Forge on and make beautiful things Jim Quote Link to comment Share on other sites More sharing options...
samw1 Posted December 22, 2013 Author Share Posted December 22, 2013 I'm sorry all, I'm trying hard to grasp the concept of natural Draft but it is a challenge for me to try to learn technical knowledge on the Internet. I think I might do what you say Jim and add a cover of sorts to help out but I'm going to need something permanent in the future. The opening of the hood it probably 9x9. I'll try to get a pic up. Quote Link to comment Share on other sites More sharing options...
Jeff Coe Posted February 13, 2014 Share Posted February 13, 2014 I see its an older post but I will jump in. Go to Grianger and look at Draft Inducers. We use them alot on fuel oil furnaces to help the draft on boilers and furnaces. The guys are right if you have a ten inch stack you need at least a ten dia fresh/combustion air coming into the building. The natural draft is just life a siphon once the stack is warm and the warm air is moving the air will sort of siphon up. You just got to get it over the hump,sort to speak. You could have other small problems, prevailing winds, locations of near by building etc. Could be more stack on top to get higher above roof line or peak. That usaully helps most of the wood stove problems I see. Any way just my two cents Jeff Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted February 13, 2014 Share Posted February 13, 2014 there is another problem. Any flue is limited as to how much air can pass through it at any given moment. You sharing the volume with the added output off the fan is taking away from what can come from the forge itself. Meaning your forge will not be able to exhause as well as if you had just ran your fan mounted on the wall to exhaust its air to the outside. We do not want anything to share a forge flue. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.