Induced Draft Fans, Powervents.

DavidW1820 · Post by **DavidW1820** » Wed. Dec. 22, 2010 2:59 am

Does anyone here have any experience with induced draft fans or powervents that would allow me to use a 500mbtu coal/wood boiler inside my basement. The house is big and I plan to use a fairly extensive heat storage tank to soak up any excess heat. The boiler was free. The limiting factor is that the chimney has a stainless 7 inch round flue which is way undersized. Building another chimney is not possible for space and aesthetic reasons. With a powerful enough fan running all the time the boiler is operating, it should create plenty of negative pressure inside the boiler. All the fans I've seen so far indicate they're only to be used with gas or oil. I'm assuming the soot would kill them or they don't have enough power or heat resistance.

WNY · Post by **WNY** » Wed. Dec. 22, 2010 6:18 am

Did you check out Field Controls? They have power venters, some pretty large.

http://fieldcontrols.com/swgsize.php

Rick 386 · Post by **Rick 386** » Wed. Dec. 22, 2010 5:30 pm

I don't think a power vent is recommended for use with a boiler. I believe it must be a dedicated chimney of some sort. Most boilers have too much coal in them that should a power failure occur, would allow too much CO in the house before they self extinguish.

Rick

DavidW1820 · Post by **DavidW1820** » Wed. Dec. 22, 2010 7:51 pm

Thanks Rick and WNY. I checked out the Field site already and they don't have what I want. The reason is that I do have a functioning chimney. It is tight and safe. It's just too small to run the boiler at its full potential. What I want is a heat resistant fan that will "turbocharge" the flue exhaust and push it up the stack with force and extra velocity. If the power dies, there will still be draft and a safe stack to allow everything to be vented while the fire dies out. Plus I only plan to run this when I'm home tending it, not 24/7 like a stoker. Maybe it's something that needs to be adapted from something else or made from scratch, because some of the outdoor boilers and stokers use some form of induced draft fans, not forced draft. The boiler will be run in a separate, fireproof and fully vented room from the living area for the purpose of CO isolation as well.

MURDOC1 · Post by **MURDOC1** » Wed. Dec. 22, 2010 8:32 pm

Maybe look at- EXHAUSTO venting design solutions??? I know nothing of these units other than they are a draft correcting chimney-top mounted fan made of aluminum and stainless... Big bucks $$$ but maybe would work for you... Just a thought...

Murdoc

DavidW1820 · Post by **DavidW1820** » Fri. Dec. 24, 2010 12:29 am

Thanks Murdoci. Exhausto might possibly work but I'll call them.

butchs37 · Post by **butchs37** » Fri. Dec. 24, 2010 5:37 am

You can try grainger http://www.grainger.com/Grainger/wwg/search.shtml ... sst=subset I just bought this one http://www.grainger.com/product/TJERNLUND-Draft-I ... Pid=search works great. If you have a grainger store near you they will usually sell it to you without an account if not you just need someone that owns a business to open one its free.

DavidW1820 · Post by **DavidW1820** » Fri. Dec. 24, 2010 1:03 pm

Thanks Butch:

I'm not sure they make what I want. Namely something inline with the flue that all the gas passes through and that really boosts it. In other words a fan like they use on wood gasification boilers that is right downstream of the fire and can take 500 - 600 degrees. The exhaustos come close but I don't want it on top of my chimney. I want it next to the chimney at its base. Those inline inducers are more like pushers and would not have the "oomph".

Dave

McGiever · Post by **McGiever** » Sat. Dec. 25, 2010 4:52 pm

DavidW1820 wrote:Thanks Butch:

I'm not sure they make what I want. Namely something inline with the flue that all the gas passes through and that really boosts it. In other words a fan like they use on wood gasification boilers that is right downstream of the fire and can take 500 - 600 degrees. The exhaustos come close but I don't want it on top of my chimney. I want it next to the chimney at its base. Those inline inducers are more like pushers and would not have the "oomph".

Dave

Maybe I'm the only one...but I disagree. This Tjernlund will do exactly what you want, and w/ a power failure you still have most of your 7" flue w/ some draft to remove the C.O.

Here's what I'm referring to:http://www.grainger.com/product/TJERNLUND-Draft-I ... Pid=search

More "oomph" than you're giving it credit for...these are tried and true for what you're trying to do.

Sounds to me like what you have in mind would not be as good for drafting C.O.after a power failure as the Tjernlund. As stated previously...You will still have a lot of coal to draft off after a power failure.