Rocket mass heater in greenhouse, any success?

Hii


I have been seeing post and forum of RMH for green house.. but i have never really see any good review out of it..

did it work ?

Did anybody tried rocket mass heater exhaust buried in green house under the bed that work ?  can to share please ?

i wanted to make it, but  i need to do some research on what other have done.. why bother wasting time repeating mistake ?

you know

RMH

.. instead of making raise bed using wood. i am planning to just bury the exhaust under the soil line and the places where the pipe goes, it will heap it up with clayiest soil.. to a certain height, like1 foot.. then on top of it i use normal soil for growing crop.

1 thing i don't know is how much distant does heat able to conduct in clayiest soil  ?
i won't want to put so thick of clay that the root of vegetable get no benefit of the heat..
so the question is how much distant does heat travels in clayiest soil ?  

how long of exhaust can i bury in ground can a normal oil barrel size

RMH

take before too cold to expel from chimney (that will be a failed heater, under i give it constant suction using exhaust fan) ?

my winter here is -7c here in UK. and day time is sometime around 0 deg c.
my winter target temperature is 7 deg c so soil temperature and some bed maybe is 15 deg c. but min should be 7 deg c.. else those over wintering plant will die.  i lost way too many plant so far using propane heater to heat air... useless.


if rocket mass heater exhaust pipe is not working in green house (that means it is not practical to conduct the heat to a such a size of a green house (let's just say slightly larger than common size greenhouse 10 meter x 3 meter ), then no point of using it.. to heat air in poly tunnel during cold weather is just like throwing money into drain. futile .

if mass heater is not work, i will resolve to use the

rmh

to heat water and use motor to circulate PEX hose buried under bed.

something about

RMH

is that when it is hot , it is too hot, ... might kill the root of plant...  that's why i need to know how much distant does heat travel to each direction in clayish soil...



if anybody have tried such thing out, please advice.
appreciate it.

thanks.

Hi Andrew;  I suggest using a raised bed over your mass . If you try to bury in the earth, it has been done but...you will lose heat to the earth.  My green house is 12'x20' . We had 2 raised beds sided with wood. I removed one bed completely and replaced it with my  mass.  A 4" layer of straw cob on the ground first keeps my heat rising instead of sinking. I surrounded the mass of rock and cob with regular red clay bricks, to allow watering. Currently we grow succulents in our greenhouse, but when we did grow vegetables,  in the spring we would place trays of baby plants on top of our mass to keep their little roots warm . After they are strong we transplanted them to the other raised bed or straight outdoors to the garden.  

hii Thomas,


Thanks for replying.

I wanted to know if it is sufficient to keep green house warm.. during winter.. is it capable of ?

i know RMH need constant feed of small fire to maintain it warm through out winter...  do you think it can maintain a min of 5c when outside is -7c ?

thanks.


andrew

Andrew; Yes , we keep our green house warm all night long with no fire from 10 pm thru 7 am. Night time temps here in my part of montana range from -10 C to - 25 C our greenhouse is apx +15 C - +25 C when we let the rocket go out and cover the feed tube, in the morning even on the coldest days it will be no less than +5 C ... many mornings when it is not so cold it will be +12-15 C with no fire for over 9 hrs.  Our 8" rocket requires new wood apx every 40 minutes when outside temps are well below 0 C on warmer days we light it in the morning hours , then let it go out for most of the afternoon and the relight it for 3-5 hours in the evening.  Before building a rocket mass heater that same greenhouse used 12-15 cords of wood and a fire 24 hrs a day to keep it above freezing. After building a RMH we use less than 5 cords of wood with no fire all night long !

Thank you Thomas, your reply from your real life experience really encouraged me.
appreciate it.

andrew