Cob Masonry Stoves

[Will Firstbrook WCB of BC]

Hi Robert,

Where can I find some information on the Contra Flow kits. I am also
interested in learning about all sorts of heating options. Ianto's
heated cob bench is made from old oil drums for the fire pit part from
what I hear. I would also be interested in the fire and bench design. He
mentioned that he likes sleeping there on cold days.

Regards, 
Will


>-----Original Message-----
>From:	Robert Bolman [SMTP:robtb at efn.org]
>Sent:	Wednesday, August 06, 1997 10:27 PM
>To:	coblist at deatech.com; strawbale at crest.org
>Subject:	Re: Cob Masonry Stoves
>
>
>Speireag writes:
>
>    In my ongoing quest for the perfect construction, I have run across
>references to masonry stoves, but no good definition for one.
>
>    How do I make one?  Must I buy one?  What are the parameters?  What
>must I allow for in construction?  Are they all huge?
>
>
>I too have an ongoing quest for the perfect construction.  On that quest
>I've also looked at masonry heaters.  They can be very expensive - enough
>so that I wouldn't feel comfortable spending that kind of money - even if I
>had it.  There are kits made up of pre-cast refractory modules for a design
>called "contra flow" that stack up relatively easily to form the basic core
>which then will presumable be covered with brick or tile.  I personally
>would consider covering the thing with cob.  You'd probably want to have
>some kind of a thin expansion membrane to avoid cracking, but after that
>you could make the thing as massive or creative as you wish.
>
>Given that much of the charm of a radiant heated slab is in having the
>warmth where it is in frequent and direct contact with the human body,
>there is a good argument for the heated cob bench as built by Cob Cottage
>Company.  Having little direct experience with them, I worry that the down
>draft combustion system that they typically employ can be problematic. 
>Also, I was recently unable to get one through the City of Eugene Building
>Department.  They have never been suitably tested.  Still though, they seem
>like a good idea.  I think of it as the poor person's masonry heater. 
>Instead of possibly thousands of dollars in fire brick, you're talking a
>few dollars worth of scrap steel parts and a lot of earth, sand and straw. 
>Being in the form of a bench, the heat is pleasurably applied to your butt.
> Due to the massiveness, the heat will presumably be retained for many
>hours after the fire goes out - especially if within a straw bale
>structure.  If designed well, little or no smoke will be visible exiting
>the chimney and the exiting gases will be about 300 degrees (F) -
>relatively cool meaning that the heat has been left where it's supposed to
>be.
>
>Any combustion enginoids care to run with that one?  I could go into
>greater detail about the down draft combustion.
>
>Robert Bolman