wood furnace build

[babetheblueox]

I'm going to build a wood furnace air to air built on about the design as a shaver Does anyone know how far should the air chamber be from the firebox?

Thanks for any help

 

[TMFARM 2009]

i dont know but if you build it out of wood wont it burn too?

 

[jackel440]

The hot air furnace I did some patch work on for a guy had about what I say 12" gap around the firebox from what I remember.
It was nothing more than a 55 gallon drum in a insulated stainless steel box.Blower chamber on the back with return air from the house.He said it worked great.Paid around $1500 for it.I thought to myself he got ripped off for no more than it was.
Good luck with your build

 

[laynes69]

I would go within 6" from the firebox. That forces the air to wash the walls of the firebox instead of going around it. If you want to think outside the box, build a fully firebricked firebox with secondary air and build a secondary heat exchanger thats seperate. Being its hot air and you are building it, you can preheat the incoming air through the firebox for secondary combustion. It will result in a cleaner burn and will use less wood. If building a secondary heat exchanger, allow easy access for cleaning the unit. Our indoor woodfurnace uses a foil faced insulation on the interior walls of the airjacket. No matter how hot the fire, the furnace walls are cold. Good luck!

 

[babetheblueox]

I would go within 6" from the firebox. That forces the air to wash the walls of the firebox instead of going around it. If you want to think outside the box, build a fully firebricked firebox with secondary air and build a secondary heat exchanger thats seperate. Being its hot air and you are building it, you can preheat the incoming air through the firebox for secondary combustion. It will result in a cleaner burn and will use less wood. If building a secondary heat exchanger, allow easy access for cleaning the unit. Our indoor woodfurnace uses a foil faced insulation on the interior walls of the airjacket. No matter how hot the fire, the furnace walls are cold. Good luck!

thats sounds interesting but im confused are there any plans or a site that would show such a furnace