Having the wood gasification boiler outside of the house

[Beno]

It seems that most of you have the wood boiler outside of the house, in a shed/barn/workshop. Though this looks as an excellent idea, no need to bring the mess in and it's easier to refuel, there are few things not clear:
1. How do you insulate the shed, so the water inside the boiler will not freeze at -30*C?
2. What will be an economical shed for the gasification boiler? Will a $1000 shed from HomeDepot be OK?

Thanks,
Beno

 

[Tarmsolo60]

I've got glycol in my system to prevent freezing if its not in use. And a backup propane heater if i'm away and extended time just for peace of mind on really cold days.
Not sure about shed, how big are they? remember you need enough air for the woodfire.

 

[hkobus]

I am using a 10 X 16 "Ben shed" a wooden shed that was at the house when I bought it. One point may be more important than insulation, is that you need to be able to store a large amount of firewood. Mine hold for a few months, not enough for my liking. I did line the building with fire code drywall where the boiler is and the rest has fibreglass between the studs with vapor barrier.
I also insulated the pipes, once my heat storage is installed, I will add glycol to the boiler loop.

Henk.

 

[BrownianHeatingTech]

If the boiler is outside, it will need glycol/water mix, to prevent freezing.

Insulating the shed can still be a good idea, as it makes loading the boiler during a storm more comfortable, and reduces heat loss (ie, improves efficiency).

The best shed to use will depend on the particular boiler. You'll need room for the boiler itself, plus the requires safety/maintenance clearances on all sides, according to the manufacturer's instructions.

Econoburn is coming out with their own shed, custom-designed for the boiler, both in terms of size and in terms of having proper access to clean and service the boiler.

Another option to a truly separate shed, is to build a utility room onto the side of the house. Insulate it like the house and heat it, making glycol un-necessary. You can even have two doors - one into the house and one to the outside. That allows you to go outside on a nice day, and move wood into the utility room, but means you can get to the boiler to load it in the middle of the night during a blizzard, without going outside at all (since you planned ahead and stored wood in the utility rooms).

The utility room idea is the best I've seen, and is what I'll be doing on my house in a year or three.

Joe

 

[Beno]

If you have the utility room attached to the house, and you have a 2 storey house, how high must the chimney go on top of the utility room?

 

[BrownianHeatingTech]

If you have the utility room attached to the house, and you have a 2 storey house, how high must the chimney go on top of the utility room?

I'm not certain what the Canadian rules are, so please check with a local about this, but the typical rule is that the chimney must go up until no structure is within 10 feet of it. In other words, imagine a 20-foot disk on the top of the chimney, and lower it until that disk intersects something. That's the minimum height. Add two feet to that, generally, just to be on the safe side.

Joe

 

[ISeeDeadBTUs]

If it's constantly circulating, very unlikely you will need freeze protection. If I let the GW go out for days aka Skiing trip :coolsmirk: then it can take heat off the Viessmann inside oil loop. Inefficient, yes. But for rare occassions, works for me. You just have to remember to reset the strap on aquastat so that the inside loop also runs continuous

 

[verne]

whats another option besides adding anti freeze. Im going to have boiler with1000 gal propane tank storage in barn . I dont plan on filling that amount with glycol. Could i run circulater pump or is it possible to run a zoned heater off oil boiler on the same loop?

 

[Nofossil]

I don't know how hard it would be to set up a timer to run the circ for five minutes every couple of hours - that should do it for even a moderately insulated outbuilding. You should have enough heat in your storage tank to avoid freezing for a very long time.

My tank is well insulated and outdoors. I calculated that if I left it unattended and unused for the entire winter, it wouldn't freeze. The boiler shoould have enough mass to be safe for a good long time. If you insulate the plumbing and circulate water once in a while, you should be safe. I'd monitor temps on a cold day just to see how quickly the most exposed pipes lose heat.