Rocket stove with 'traditional' skinny pipe underfloor heating?
Post by:Julie Garrett
I am no where near construction stage yet, but I was wondering about the possibility of having the more normal skinny pipe wet underfloor heating system with a separate pump added to the rocket stove mass heater?
Basically I'm thinking that the whole house could be set up with the mirco bore pipes under the floors, with the usual pump and switch, but have the pipe wrapped around the stove or passed through the mass somewhere to pick up its heat from there?
The downsides I can see are, you wouldn't be able to have the pump on a timer as there would be no knowing when you would be using the stove. You could only have the underfloor heating when the stove was lit, and/or there was heat in the thermal mass. The underfloor heating system would cool down the thermal mass faster than it would normally cool down. Without experimentation there is no knowing how far away from the high heat of the rocket stove itself the micro pipes would have to be, so they didn't get too hot (no one wants to walk on a floor that can burn feet).
The upside I can see is that on chilly evenings you could light the rocket stove and have the underfloor heating on all night and wake to a whole house warmth the next day, before you top up the heat again.
I'm sorry if this has been asked before, if so can you link me to the relevant thread.
Post by:Mike Leo
I assume by "micro bore" you mean the standard 1/2" or 3/4" copper water pipes?
What you describe is possible, and in my imagination could even be fully automated with thermostat if you designed it right.
You are also squarely in the realm of BOOMSQUISH. Which is Paul's way of saying you probably shouldn't try this unless you are a water/heat/steam professional because by the time you notice the BOOM you will already have been SQUISHed.
I do have a few recommendations for you if you haven't seen these resources already:
2) I also highly recommend all 4 of the new Wood Burning Stove 2.0 DVDs, but if all 4 are out of the question specifically the BOOMSQUISH DVD (which, you should know, does not show you HOW to do this but does go over what you need to think about in detail and shows a system that works).
Perhaps you've already done all of this, if so I apologize.
You may find that with an RMH installed that piping of heat is just unnecessary, or that it wouldn't be worth the tinkering. At the very least you will have built a system that you know will work and can take that experience away with you before you start to innovate.
The most important take-away is something you probably already know and just haven't thought about. Ernie and Erica don't do this. The primary innovators and researchers in this space choose not to mix water and RMH technology. I understand that part of that stems from what I've already said, the danger potential is real, especially for a backyard innovator.
Post by:Julie Garrett
Thanks for the reply and links.
I can understand the BOOMSQUISH aspect. Years ago my ex-husband plumbed in a multifuel back boiler for radiators and hot water, but didn't put in a relief valve. Nearly every night, midwinter, after he had banked the fire, we would be woken by the pipes banging and the cylinder 'growling' to itself. The only thing we could do was get up and run half a bath of hot water to force cold water into the system.
Those links will be great. As for the DVD's, at the moment they are well out of my price range, but closer to the time, they will be budgetted for.
Post by:Diane Smith
I realize there is a long thread of conversation here and on other posts, and I'm going to start fresh with my plan. I'm building a 700 sq ft yoga studio on Hornby Island in BC, Canada. I need in floor heating for all the obvious reasons. We have frequent power cuts through the winter and in the long run electricity is an expensive and un-eco solution to what I hope to alternately produce here. With respect to all those previous contributing threads to this discussion, is there a response out there to this question? What might be the simplest rocket heater heated floor that we could dazzle innovation with?
with standing ovations for the brilliant minds at work in this field,
Post by:allen lumley
Julie and Diane : This is a break for me, I have been a rabid, rock ribbed denier of the basic possibility of a ' Wet ' Rocket that successfully combines a water heater with a
space heater ! You should consider that the rocket stove needs to come up to freakishly high Temps to create its high efficiencies!
Downstream from the 'Rocket Burner' part, somewhere firmly in the middle of the Cob Thermal Mass Bench* you could extract water at a temperature safely below the
temperature of steam (212 F degrees) , AND this High Temperature water could then be passed thru a Mixing Valve that uses no additional input of energy to Mix the
combined water temperatures to a Temperature that is safe for the Pex plumbing within the floor !
The remaining Problems are the necessity to pump water thru your system and the need for a careful and well trained operator who can not only operate this system during
normal operations, and having a simple system that the operator can safely shut down when a problem occurs !
The frequent loss of power that you experience,and the loss of electricity to 'run' your needed circulating pump(s), complicates your build, and incredibly complicates the
amount of direct hands-on attention that your entire 'in floor hydronic heating system' needs, often at the very time you MUST give time and attention to your paying
customers, this can easily result in a clash between your backed up 4 o'clocks and your 5 O'Clocks, and what were your plans for changing, and showers for your clients and
most importantly for your staff, who must always seem, and smell fresh ?
Today there are several groups of people who are using Hot Water from Wood Boilers, which are a very energy wasteful way to create Space Heaters! Because these units
exist, many people accept without any research that 'Hydronic heat' must be possible from the 'Rocket Mass Heater R.M.H.', there are many do it yourself plans out there,
and an incredible amount of Crap to be found in U-Tube land, so that many people are willing to try building this Bastard hybrid !
I can only suggest patience, there may be a safe unit created when a water circulating pump is created that can work off of the heat energy contained within the pumped fluids
until then, you could go to 'rocketstoves.com' to get your PDF Copy of Ianto Evans' great book 'rocket mass heaters", there is STILL No other Book in any Language with more
rocket stove family information ! (and I don't make a dime ! )
For all things Permies, Think like fire, flow like a gas, Don't be the Marshmallow! As always, comments and questions are solicited and welcome! PYRO - Logically BIG AL !
*I have a friend who teaches Pilates from her home, who has a R.M.H. Thermal Mass Cob Bench with a two station raised Pilates beds, often her clients book to come in and
relax with the heat 15- 20 minutes before the start of an active session ! A.L.
Post by:Frere Daran
About a year back, I posted a note about producing hot water by extracting heat from the thermal mass (below boiling temp) instead of the stove itself (boom-squish style). The idea is to make the system more simple, robust, safe and stable, all because of the much lower and stable temperatures in the thermal mass.
You don't get instant hot water, but then you also don't risk blowing your house up...
Link to my post: http://www.permies.com/t/22031/rocket-stoves/Quick-Easy-Rocket-Stove-Hot