Catalytic wood boiler

[Rory902]

Hey all, long time reader first time poster here. I've been searching for info on a catalytic wood boiler that can burn long and low like a catalytic stand alone stove, but can't seem to find anything. Does this exist, and if not, why?
It seems like it would be a great way to avoid needing storage in my 115 year old house with cast iron rads, but as I can't find a single model, I'm guessing I'm missing something?

 

[maple1]

I have never heard of or seen one. Might have something to do with it being a bad match to a liquid cooled firebox. But I don't really know. I don't think there are any catalytic hot air furnaces out there either.

 

[Rory902]

I'd really like to use a wood fired boiler. We currently heat about 50% with an oil fired boiler and 50% with a newer wood insert with secondary burn, but the price of oil is likely to keep rising and in our area I can get seasoned hardwood for $100/cord. The main issue is we don't have much room for a properly sized hot water storage system to go with it.

 

[brenndatomu]

Might have something to do with it being a bad match to a liquid cooled firebox.

This...^

I don't think there are any catalytic hot air furnaces out there either.

BK used to make one...they have since quit but it sounded like the door was left open a crack for the possibility of making them again in the future...

 

[MikeK]

I think there have been attempts in previous years. I looked at some Hardy boilers at a dealer in my state and if my memory is correct he said the one he was currently using to heat his home used to have a catalytic combustor. Also Woodmaster's new outdoor boiler has a catalytic combustor. I don't know if it would be a long and low burner. http://www.woodmaster.com/product/cleanfire/ . I couldn't see a picture of the combustor, but I watched a video at their website and it said it has a "catalyst".

 

[Fred61]

Catalytic combusters need to get quite hot in order to make them hot enough to ignite and then the fire needs to be somewhat hotter than anything I'm comfortable with to maintain the burn in the catalytic chamber. Higher temperatures may not be possible in a chamber surrounded by water.

 

[salecker]

I'd really like to use a wood fired boiler. We currently heat about 50% with an oil fired boiler and 50% with a newer wood insert with secondary burn, but the price of oil is likely to keep rising and in our area I can get seasoned hardwood for $100/cord. The main issue is we don't have much room for a properly sized hot water storage system to go with it.

Hi Rory
Just build a boiler building.I built one for my system it is 24x26 i built it out of recycled building materials so it cost my time and a few $$ for the concrete,insulation and garage door.It is the best choice for us because it keeps the mess and smoke out of our house.My wife and daughter have asthma.Plus we have no flame source in our home,no chance of carbon monoxide poisoning.We loss a little heat having everything in a separate building,but i use the building for a workshop all winter so it has it's benefits as well.We have our backup oil boiler in the same building.
Even with this last stretch of -40 weather i don't mind the walk every couple of hours to fill the boiler.Plus my wife is very happy that it has it's own building and yes she tends the boiler as well.I have the room to keep a few days of wood inside which gives the wood a chance to warm up and dry if you have any wet wood.
I am thinking of putting a boiler system in a 20ft container at my shop, if i still own it once getting waste oil becomes a pain.Having a wood burning stove in a garage has a big list of regs here.
Thomas

 

[Highbeam]

Catalytic combusters need to get quite hot in order to make them hot enough to ignite and then the fire needs to be somewhat hotter than anything I'm comfortable with to maintain the burn in the catalytic chamber. Higher temperatures may not be possible in a chamber surrounded by water.

It’s the opposite. Catalytic combusters fire and burn clean at less than half the temperature of noncat designs. Then the fire can smolder cold and the lit combustor stays lit to burn the smoke. It’s far easier on the appliance.

In boiler land you want higher combustion temps to heat the cold water with a big differential. That may be why the cooler running cat systems are not favorable?

 

[sloeffle]

My neighbor has an OWB that has a tray of catalytic combusters on the bottom of the boiler. From what I remember there were 6 pretty big catalytic combusters. I'd hate to have to write the check to replace them whey they start going south. At this time I can't remember the name of the brand of the OWB though. I drive by his house everyday and it looks to be a smoke dragon. I am pretty sure he isn't burning seasoned wood too.

Edit. Some googling and racking my brain has lead me to believe he has a Natures Comfort GT series boiler.

 

[brenndatomu]

My neighbor has an OWB that has a tray of catalytic combusters on the bottom of the boiler. From what I remember there were 6 pretty big catalytic combusters. I'd hate to have to write the check to replace them whey they start going south. At this time I can't remember the name of the brand of the OWB though. I drive by his house everyday and it looks to be a smoke dragon. I am pretty sure he isn't burning seasoned wood too.

Edit. Some googling and racking my brain has lead me to believe he has a Natures Comfort GT series boiler.

That appears to be a straight gasifier if that is indeed the one he has...which isn't going to work out real well with green wood as you said. That, and some storage so that it can heat up and run through a load without trying to idle...haven't seen anybody idle one cleanly yet...maybe one out there somewhere...IDK.

 

[sloeffle]

That appears to be a straight gasifier if that is indeed the one he has...

The manual that I linked to shows a clean out door for the catalytic converters ( 6 total ). The catalysts aren't as pricey as I thought they would be. The one for my old wood stove was around $80 for one.

 

[brenndatomu]

The manual that I linked to shows a clean out door for the catalytic converters ( 6 total ). The catalysts aren't as pricey as I thought they would be. The one for my old wood stove was around $80 for one.

Yeah, I looked up a sales brochure...it looks like the 6000 does have both down draft gasification and cats...that should be a pretty clean burner, if he fed it some dry boiler chow that is...

 

[Rory902]

thanks for all the replies everyone. I've been looking at the woodmaster cleanfire mentioned by mikek, looks interesting but I haven't found any real life info. I'd be curious to know about average burn times and if it burns dirty when idling. The t joint furnace bypass it uses to regulate water temp seems cool, but maybe not the most efficient.