Need advice picking a ventilation fan for my barn...

[moneyisflying]

So, while finishing my barn (30'x50'), and getting my wood burning stove out there going that I use to heat the barn up. I get a bit of smoke on initial light up of the furnace. I have adequate draw, and honestly after the fire is lit, and there is "some" heat, the smoke goes right up the chimney as its supposed to. However, it does leave some smoke in the barn from the initial light up. I did insulate the barn and its sealed up pretty good. So far, opening the giant 18' garage style door is what I have been doing to ventilate the smoke out, but during winter this isn't really ideal as the smoke rises and the door only goes up so high. Plus, after I am finished with the barn, I would like to weld, and do other projects out there that I may also want ventilation for.

My question is, what ventilation fan should I get? I want something that will work well, but at the same time not let all my heat out when I am not using it either (I want something that seals up pretty good when its not used).

This is the unit I was looking at, but I don't really know much about them, or what would fit my needs.

https://www.amazon.com/dp/B000IJRD5S/?tag=atomicindus08-20

 

[Dagny]

That is going to fight the draft on the chimney.

 

[Dagny]

When the chimney is cold it will draw less try starting smaller fire and do whatever it take on your setup to allow more heat to go up the chimney then gradually increase fire size as draft increases.

 

[moneyisflying]

When the chimney is cold it will draw less try starting smaller fire and do whatever it take on your setup to allow more heat to go up the chimney then gradually increase fire size as draft increases.

Okay, I shall try that. I do start small, but regardless of starting smaller still, the chimney will always be colder than the wood stove, so I would think I would still get some smoke initially any way I do it. I will try to go on an even smaller scale next time and see how it goes. I will add that the wood stove has a door that I do close and then there is zero smoke. It's just that I must leave it open until he fire gets going a little bit or closing it will put the fire out.

Other than that, I still do have other projects like welding that I would want the ventilation for. Can anyone give me some advice about which on would be best for my needs? One other big thing here is that I don't want to lose the heat my wood stove is giving off, so having something that seals up good is important.

 

[willymakeit]

Do you have outside air to your stove?

 

[willymakeit]

I have outside air on my stove. It helped plus once the shop is warm ,I don't have to use my heated air. Also less chance of fumes being drawn into stove.

 

[moneyisflying]

I do. So I made the stove from a 55 gallon steel drum kit. I have a chimney made with good draw. I also put 2 large pipes into the barrel and drilled holes in the pipes. The 2 pipes fit together into 1 on the outside of the drum and I have a blower hooked up to it. When the blower is on, it does an amazing job of heating up the stove.

Again, when the stove gets warm (which it takes all of 5 minutes to get there) there is zero issues and there is no smoke. It's just getting it warm and keeping it going with a small fire requires me opening the front door on the stove and the smoke does go out the door there. If I close the door when the fire is so small, the fire goes out (not enough oxygen). The holes that blow air don't really help until the fire gets going.

Again, this is partially to fix getting rid of the smoke that rises, but it's also for other projects that I would want the ventilation for, so even if I fix this issue, I still would want the ventilation fan.

 

[Ole Slewfoot]

if you install an in fan, you can close the door, turn on the fan and light your stove. the positive pressure in the room will create a draft up the chimney, and you should have barely any smoke escape to the room.
Something like this will work for that
https://www.amazon.com/dp/B009LCEUEK/?tag=atomicindus08-20
but a 10" or 12" on a Harbor Freight router speed control is quieter when you don't need full speed/force, and would do a better job of displacing weld fumes.

Indiana may be different, but here if you look on Craigslist for used grow equipment there are usually a few choices.

 

[moneyisflying]

I have tried lighting the fire and closing the door with the blower going. As said before the fire goes out every time.

 

[BruceMc]

Are you priming the stove pipe first? Just take a small wad of newspaper, put it directly under the stovepipe inside the stove and light it off. Even better if you can get the newspaper up in the pipe.

 

[moneyisflying]

That's not something I have tried. I'll give it a shot.

 

[BruceMc]

You just want something hot (with little smoke) to give the stovepipe a slug of hot air. Once you overcome the inertia of the cold air in the pipe and get it drawing, you should be good to go.

 

[Bretny]

A small amount of smoke getting out can just be the nature of the beast when lighting from cold. I have never used a barrel stove so idk what the issue could be. Paper lit in the stove pipe is always my quick fix but never have the problem with my top load stoves.

 

[moneyisflying]

Here is the thread to my pole barn build. On the first page of the post are pictures of my wood stove so you can get a better idea of it.

https://www.garagejournal.com/forum/showthread.php?t=237728

I wonder if heating the pipe with a small torch would do the trick? It's not ideal every time but it would get the chimney hot quick if that's all I may need for initial draw.

 

[BruceMc]

That's a really nice looking space. Hopefully you have some snow brakes installed on the roof above the stovepipe? That's a pretty vulnerable spot (a sidewall) to put a pipe through - snow sliding off will potentially take the pipe with it. Might want to think about a gutter there as well. At least enough to keep rain from directly dripping on the pipe.

 

[moneyisflying]

That's a really nice looking space. Hopefully you have some snow brakes installed on the roof above the stovepipe? That's a pretty vulnerable spot (a sidewall) to put a pipe through - snow sliding off will potentially take the pipe with it. Might want to think about a gutter there as well. At least enough to keep rain from directly dripping on the pipe.

Well thanks

I have made re-inforced steel braces on the chimney. Trust me when I say there is no amount of snow from that roof that could potentially ever move that chimney. I spent the money on the expensive full stainless double wall pipe also, so rain isn't going to hurt the pipe any way I could think of. It's completely sealed. Even after a downpour outside there's never been a drop inside the pipe (I checked many times on this after the install initially).

The company who built the barn spoke with me about gutters. He swore that in the first 6 months I would have large trenches made by the water especially in the back on the non gravel side. Funny, it's been 3 years now and I haven't noticed a thing. Only issue I have had earlier was in one area where some water would pool up after heavy rain. But I fixed that earlier by installing s drainage pipe (which has worked awesome since the install).

 

[BruceMc]

Well, it's not loose snow that can take it out, it's when you get into freeze/thaw cycles and you get slabs of compacted snow mixed with sheets of ice. Just speaking from personal experience. These are pretty typical examples if you don't have one installed already. I couldn't tell from your pictures.

http://www.roofthings.com/snow-diverters.html

 

[bad_idea]

The most effective method of ventilation for welding fumes is exhausting at the source. Here is a good article laying out the basics: http://www.thefabricator.com/article/safety/breathing-easier

To ventilate the entire barn will be costly. Both in the cost of an adequate fan, and in the loss of conditioned air. You will also need a source of fresh air coming in, either cracking a door or window, or an inlet vent. First you will need to calculate what size fan you need. This site has good information and a calculator for that: https://www.engineeringtoolbox.com/air-change-rate-room-d_867.html

Assuming you have 12' ceilings, and are changing the air at a rate of 20 (based on the chart in the link for a garage) for the entire building you will need a fan capable of 60k CFM to properly ventilate the shop.

I work in Ship Repair, both on the ships and in a shop. In the Weld Shop they use general ventilation, large ventilation fans to exhaust the fumes and inlet vents. It stays chilly in the Weld Shop, and there is a layer of smoke up near the ceiling (around 25') when they are really cranking. On the ship we use local exhaust, either a exhaust hose 12" or so from the work or a smoke eater. A smoke eater is basically a HEPA vac on steroids, purpose built.

 

[BruceMc]

To ventilate the entire barn will be costly. Both in the cost of an adequate fan, and in the loss of conditioned air. You will also need a source of fresh air coming in, either cracking a door or window, or an inlet vent. First you will need to calculate what size fan you need. This site has good information and a calculator for that: https://www.engineeringtoolbox.com/air-change-rate-room-d_867.html

Thanks for that - that led me to:

https://www.engineeringtoolbox.com/garage-ventilation-d_1017.html

which gave me a couple of ideas for my own situation.

 

[moneyisflying]

Well, it's not loose snow that can take it out, it's when you get into freeze/thaw cycles and you get slabs of compacted snow mixed with sheets of ice. Just speaking from personal experience. These are pretty typical examples if you don't have one installed already. I couldn't tell from your pictures.

http://www.roofthings.com/snow-diverters.html

I understand what you are saying, but understand that it still would not make a difference. You'd have to drive a small car into the chimney to move it for how overkill I went on the steel supports. Also, this winter will be the 3rd winter with it up. If it hasn't happened yet, I'm sure I'll continue to be good in the future.

The most effective method of ventilation for welding fumes is exhausting at the source. Here is a good article laying out the basics: http://www.thefabricator.com/article/safety/breathing-easier

To ventilate the entire barn will be costly. Both in the cost of an adequate fan, and in the loss of conditioned air. You will also need a source of fresh air coming in, either cracking a door or window, or an inlet vent. First you will need to calculate what size fan you need. This site has good information and a calculator for that: https://www.engineeringtoolbox.com/air-change-rate-room-d_867.html

Assuming you have 12' ceilings, and are changing the air at a rate of 20 (based on the chart in the link for a garage) for the entire building you will need a fan capable of 60k CFM to properly ventilate the shop.

I work in Ship Repair, both on the ships and in a shop. In the Weld Shop they use general ventilation, large ventilation fans to exhaust the fumes and inlet vents. It stays chilly in the Weld Shop, and there is a layer of smoke up near the ceiling (around 25') when they are really cranking. On the ship we use local exhaust, either a exhaust hose 12" or so from the work or a smoke eater. A smoke eater is basically a HEPA vac on steroids, purpose built.

Thanks for the info!

 

[isb cornbinder]

https://www.grainger.com/content/supplylink-how-to-choose-the-right-exhaust-fan

 

[kbs2244]

I am going with the cold chimney idea and therefor a lack of draft.

And the easy way to get a draw going is a good sized wad of newspaper.
You need to take it slow in a case like this.

Newspaper lighting small fire tinder lighting full sized burn load.

 

[Ole Slewfoot]

I have tried lighting the fire and closing the door with the blower going. As said before the fire goes out every time.

I think you read me wrong, should have specified close the door to the building, so the ventilation fan can pressurize the entire building. Now the chimney being the biggest outlet will flow in the correct direction.