These have been very successful builds. They heat up really fast and work well. So far pizza's (lots) , sourdough chocolate cake and a lamb roast are a few of the things we've cooked. I stuck to the original build plans with a couple of small exceptions. Am hoping to run some workshops this year here in Covid free NZ and will be "bundling" Davyn Hoyts plans (I've discussed this with him) for the participants.
Finished oven[/url]I'm about to start building my fourth so far this year.
Three of them are built in/for local community gardens.
Using plans purchased from Davin Hoyt and video from permies.
Here's some pics for interest.
Hot water rises, cold water goes to the bottom. Inlet and outlets in these designs are both in wrong place. Tub should be higher than coil etc etc. Huge potential for explosions here - with both designs.
Unless you plan to force the water to circulate you may have a bomb on your hands!!
Cold inlet to coil need to be from the bottom of tub to bottom of coil, hot outlet at top of coil. to top of tub.
Tub needs to be higher.
Horizontal coil might work if circulation pump used - a pump failure could be catastrophic though
Paul, you say at the beginning of this thread that you are "... getting kinda sick of proving shit". I, for one, don't think you will prove anything by measuring the volume of wood you are burning. Measuring and comparing the weight of wood burnt would be only the only reasonable comparison given what we all know about the amount of energy contained in a given weight of wood/as opposed to volume. Saying that as you are the one who is "doing the work, I am choosing to follow the universal standard format for measuring firewood: the cord" contributes nothing to the discussion, or your own credibility. The cord is indeed a universal measurement of wood for when it is sold, but not as a measure of its calorific value - this is usually reflected in the price that is paid per cord.
Tree Lucerne/Tagasaste/Chamaecytisus Palmensis - nitrogen fixer, hens love scratching around under them and eating the seed pods. It coppices easily and is very hot burning. just don't cut it in the winter time. Stock love eating the leaves and its very nutritious. Loves the dry too. Awesome plant
Just finished building one a couple of weeks ago, with an outdoor bath rather than a tub.
Its not been built as I had hoped but it works nevertheless.
More rise on the pipes, a return flue pipe in the mass and less insulation around the drum would have improved overall efficiency. Insulating the water heater itself should also improve things. Photos attached are of the first burn out of the core and then the nearly completed setup. I can post more pics if people wish. The bath itself is insulated and the pipes are lagged.
This is probably one of the better examples of insulated refractory casting on Youtube https://youtu.be/7ANMXGrxgnE - he describes the mix at 3.17. I've used this to build three cores (using either perlite or vermiculite) to date and they are working very well. I have molded fire bricks around the feed tube as that's where all the wear and tear happens.