Jason Matthews

John Todd wrote:Sounds good.  I will try a few loaves and report back soon.

How did you get on John?

Mike Leo wrote:When working properly, the burn works just as efficiently either way. It's basically the whole point of the rocket tech in the first place, super hot, super complete burns which produce more total heat for less total fuel.

So you have net heat (H) from a burn at max efficiency. That heat can go 1) into your space 2) into mass (then later into the space) 3) or out with exhaust. It's the control between these 3, not variations of H that give you your answer.

What sort of space is it?

thanks Mike. Its all theory at the moment.
Lets say I wanted to heat a room about 25 sq metres (270 sq foot). If I only wanted it heated quick to use it for an hour how long (if switched to divert away from the thermal mass) how long would it take roughly to heat up a cold room? Also how long would the room stay warm in this mode - can it be fed to pretty much heat it for that hour and then tail off nicely to not waste fuel?

This video got me thinking about a few things, hence this 2nd thread for clarity.



I was thinking of the situation where you may need on occasions a room heated really quickly and you only need the room for an hour or so - does this to achieve that aim by significantly speeding up heating time and if so by how much (I realise if it does it also means it will cool down very fast)
Is it just a case that using the bypass the barrel is heated must faster, as its not heating the thermal mass, giving off faster immediate but shorter in time, radiant heat to the room?
I take it that divert process is no less efficient?

Mike Leo wrote:Sometimes you don't want to heat the whole house, just enjoy a bit of fire or heat up a cup of tea. That bypass would almost turn your Rocket Mass Heater into a Rocket Stove with a simple built in adjustment.

Also, even during the winter time, as Erica mentions in the video activating that bypass "reduces drag" which you can translate to "improves draft". Especially during starting the RMH having a better draft will keep things cleaner, get the rocket to operating temperatures faster and basically improve a lot of the experience.

I am going to start a new thread about this for clarity as I want to ask a related question to this.

@ Allen. Yes it might be a tough sell! It's hard to know what the statistics would be for Boom Squish fails if lots of people had these water heaters, either in their current or more advanced form.
They could even be more safe than gas - who would want that in their house after seeing this bad boy?

http://www.youtube.com/watch?v=ap02Gnq5LKU

Thanks Mike and Allen for the detailed answers.
Much if this is very new to me and with zero knowledge of plumbing much of its it is lost on me as well. Maybe with further development the Boom Squish might become a thing of the past?

allen lumley wrote:
So let me turn this around and ask you, knowing as much as you know right now, how would you go about writing a safe operations check list for operation of your shower so
that both Mike and I could safely use your heater to take a simple shower ! it is also important to get the opinion of any significant other also !

I think I'd ask everyone to sign a disclaimer!

Does anyone think RMH's will ever be made by a large company as a mainstream consumer heating device, or is it likely to be one for the enthusiasts only?

@ Allen

Lets assume we install one of these bad boys outside but quite near the home/building but was feeding an indoor hot water tank. Would I be right in saying that the hot water tank would be totally safe indoors?

@ Allen

This seems to imply the design can be made safe enough:

https://permies.com/t/3352/rocket-stoves/Rocket-Stove-Water-Heater#28029

and this is similar:

http://permaculturenews.org/2013/05/20/how-to-build-a-rocket-stove-mass-water-heater/
http://www.youtube.com/watch?v=YTnr8ua54Uw

I guess they are outdoor for the reasons you mention, but it looks a very workable system. Could you comment on the safety of these?

allen lumley wrote:
Learning How to safely use a Rocket Mass Heater To Safely function as a hot water heater should be contemplated as a 5-year Project, this is because of the many ways
that it is possible to make a mistake and Cause an expanding steam explosion, referred to here at Permies as ' Boom - Squish ' Think boston massacre with more 2nd
and 3rd degree Burns ! If you have not already seen the 'Mythbusters ' Video exploding water heater you can search for it on You Tube !

5 year project? I take it the Boom Squish DVD doesn't address the safety issues with heated water? Is it really too tricky to devise a failsafe mechanism?

thanks Mike - It begs the question if anyone has done something like this?