Starting fire in a Rocket Mass Heater

Hi!
I'm very interested in building a RMH in my semi-tiny house in southern Sweden.

One thing I'm pondering is how to get the smoke going in the right direction as you first light it up?

I've been looking at youtube, and so far not seen one being lit. However in one video it was mentioned that draught automatically goes the right way when the temperature difference between outside and inside is big. Thus long, extended spring or fall is not ideal. Also it is mentioned that wind can blow the smoke in.

In my part of southern Sweden, the entire winter can be foggy, rainy, windy and a temperature that fluctuates just a little above or below freezing. My conventional, modern cast-iron fireplace is hard to start a good draught in in foggy or rainy weather. So how would it be with a much longer pipe with bends?

Do any of you have a RMH in such a climate? How easy is it to light without smoke coming in?

A rocket stove connected to a mass would be far more difficult to start than a box stove, so what people do to avoid this issue is use a bypass.
A bypass simply directs the heat straight up the chimney until the stove becomes warm and then  the by pass is closed so the fire can heat the mass.
This can just be a simple twist of a handle to open or close the bypass.
There are other possible issues like how direct the chimney is and if it is insulated, a tall, straight and insulated chimney can make a huge difference.
Of course the rocket stove design and build quality can also make a difference, some stoves have to bit lit in a certain way like from the top of the batch of wood, others just need a bit of kindling and a single match!  
Some rocket stove only  supply radiant heat and dont have any mass, this style is very easy to light.

The mass and ability to store and slowly release heat is my main reason for wanting a RMH, so for me, the bypass options would be what I need to learn about.

Do any of you know where I can find more info?

Hi Tuve;
check these out) https://permies.com/t/155372/Installing-Bypass-bell
https://permies.com/t/159700/Retrofitting-Piped-Mass-Bypass-Install

One thing about RMHs is, once you get your mass up to operating temperatures you will not have draft issues.
All winter your RMH should start with no problems.
Starting a cold RMH can be a minor problem.
By installing and using a bypass that issue is eliminated.

thomas rubino wrote:Hi Tuve;
check these out) https://permies.com/t/155372/Installing-Bypass-bell
https://permies.com/t/159700/Retrofitting-Piped-Mass-Bypass-Install

One thing about RMHs is, once you get your mass up to operating temperatures you will not have draft issues.
All winter your RMH should start with no problems.
Starting a cold RMH can be a minor problem.
By installing and using a bypass that issue is eliminated.

Was wondering, if the "in pipe butterfly gate" is simply is not positive enough of a airflow stop? (when closed), vs your excellent slide gate.  it certainly appears that a pretty small by-pass opening, will suffice on getting things going in the right direction.

Both are easy enough to make, just that one is "easier"   ;-)

Hi Scott;
I think that a home-built inline butterfly damper with no extra holes would do the job.
A guy handy with a welder could fab one up... Know anyone like that near your house?
My blast gates are fast and easy for folks who do not have a welder.

thomas rubino wrote:Hi Tuve;
check these out) https://permies.com/t/155372/Installing-Bypass-bell
https://permies.com/t/159700/Retrofitting-Piped-Mass-Bypass-Install

One thing about RMHs is, once you get your mass up to operating temperatures you will not have draft issues.
All winter your RMH should start with no problems.
Starting a cold RMH can be a minor problem.
By installing and using a bypass that issue is eliminated.

Thanks!
I must admit, though, that I am struggling at this forum, for several reasons. My English is good enough, but many of the technical terms, names of materials, components and tools etc are unknown to me. And then I need to painstakingly translate all sizes and temperatures to metric and Celsius. On top of that I have never yet seen a rocket mass heater irl, and I'm trying to follow the discussion between people who have already built several.

I am only at the beginning stages of figuring out how to design a rmh that will suit my house and climate. Maybe I should start a "metric newbies" thread?

Tuve, Peter Van Den Berg's website has both metric and english measurements. He is based in the Netherlands.

BatchRocket.eu

Great! Thanks!

Jeremy VanGelder wrote:Tuve, Peter Van Den Berg's website has both metric and english measurements. He is based in the Netherlands.

BatchRocket.eu