Rocket Mass Heater Shippable Core

Hi I'm new here.  I bought your book a few years ago but I am stumped by the regulations here in New Zealand,  looks like the green house is the only place I can legally build a rocket mass heater.  But I digress, the reason I post is that I came across  this manufacturer of rocket cores.

http://www.dragonheaters.com/rocket-mass-heater-shippable-core/

What do you think?

They say...

Why use a Dragon Heater Shippable Core in your Rocket Mass Heater?
Using a Dragon Heater Shippable Core for your rocket mass heater makes construction faster, easier, and your heater's performance will be superior to what you can achieve using traditional approaches. A Dragon Burner will outperform a traditional rocket heater, because it is made of superior materials, has an optimized (patent pending) burn tunnel, and utilizes secondary air channels for complete combustion.

Pre-Engineered Rocket Mass Heater
Countless people of have put days of labor into their rocket heater project only to have it fail. This happens because the rules for sizing the various parts in relation to each other have been difficult to understand and unsuitable materials have been substituted for the proper ones. By using a Dragon Heater, you are assured the engineering is right and it will last. You don’t want a heater to fail when you need it most.

I realy like some of the features in the casting
http://cdn1.bigcommerce.com/server4100/lmpge/product_images/uploaded_images/03-12-6in-insidecompressed.jpg

Hi Jack.

Welcome here.

Well, this is the core developed by Peter van Den Berg.  You can read the whole story here.

http://donkey32.proboards.com/thread/355/small-scale-development

I find the price of the cores very high . But that's just me. The dragonheater people use to come here, just to drag business. And nick other peoples ideas. So you can sense my feeling about them.

In fine, you don't need a cast core to make your own rocket mass heater.

Plus, i would say, i'm an advocate of the higher powered batch rockets.

http://batchrocket.eu/en/

Thanks for the reply Antone

I completely understand with the cost issue and yes I too like the look of a batch rocket.

What I most liked about the dragon was the insulation around the fire tunnel.  That must bring it up to working temperature faster than a clay brick j tube.  But there again if a clay brick design breaks I can fix it myself...


Here is where I'm at; I have a pile of old clay bricks (enough for the j tube + a few), a bag of fire clay, a bigger bag of perlite, an oil drum (now without top, burnt out and cleaned up) and a few lengths of 6 inch stainless flue pipe I salvaged.  I have good volcanic clay a spade's depth into my garden, so I think all I need now is sand and straw. I'd like to build the rocket mass heater in my workshop which is under my house.  As my workshop has concrete floor and walls this should work safely. The trouble I'm having is with the other half.  She's worried about the insurance cover with an unpermited stove.  So with plans on hold it might end up in a poly tunnel, sigh.

Hi Jack.

Well, a cast refractory goes up fast in temperature, but not as fast as an insulating firebrick one. That's an example.

Clay and perlite cob might heat up as fast.

Well, regarding the other half issue. Build one outside, a complete one, but that you can dismantle later. And show her how safe it is.

Than again, i advocate  the batch, because it is a mass heater. And can be insured as one. If you know the norms, clearances etc. You wouldn't be insured with a dragon heaters core.

Hth.

Max.

Jack where in nz are you based I'm in taranaki and have just cast my first 4 inch peterberg batch box and riser below is a picture of my prototype to heat a bath ( max I did extend the riser now she's mental hot) but I lit the cast one the other night what a difference box on floor level flames extending out of riser to 6 ft above the ground.

Hi Russell, I'm way down south near Dunedin.

Thanks for sharing your set up, I like it so far.  It looks hot enough!

I'm leaning towards a 8inch/200mm batch type mass heater too.  I'll make one outside.  If all goes well I'll then build a poly tunnel over it.

Here's hoping NZ coding comes round to excepting these things.

Hi Max thanks for your reply there's good info in it.
I'm now leaning towards a 8inch batch mass heater in the garden.
Lots of reading first.  I will post results on a new thread when I've got something to show.  That may be a wee while as I'm waiting for back surgery.

Jack

Jack here's an article about a masonry heater built in Queenstown. I'm doing some research into it to see if it's possible to use this example as an application to build similar with a batch box as the core if we both look into it we may have some luck.

That's good news.  New Zealand could do with some more fire knowledge like this.  I just hope that the coding catches up the progress being made with these better ways of burning wood.

I also found this today.