Using coal in a rocket stove.

I have a rocket stove mass heater in my place.  I live in the south, where it is fired now and then, not a daily thing.  Only when a cold front comes in.  So lots of time we are out when the cold front arrives, and we get home late to a cold house and we want to go to bed.  It takes 4 hours to heat our mass, so it is a very cold house in the morning.  Now, I am around coal fires, hubby and I are hobby blacksmiths.  I know several people that put a bit of coal in their wood stove at night to keep it going until  morning.  I have been wondering what would happen to coal in a rocket stove?  Will the rocket stove burn it cleanly?  Will it stay burning longer, so the bench will heat and I could go to bed?  I am thinking that if we have a stove that will re-burn the gasses, like a properly designed rocket stove, then it should be safe.  comments welcome.

Hi Kim;   Yes I have burned some coal in my rmh, but only after everything was heated up. Would you be able to safely toss some coal in your not really hot rmh and go to bed Maybe... but I would not do it .  Come home run the rocket as long as you can add a blanket and go to bed , heat the house in the morning. Or keep a metal box stove hooked up on another chimney to use when you can't be home to heat your mass. Stoke up the box stove for the night ... heat the rmh in the morning. Last and absolutely the worse choice would be a power sucking electric space heater (ewww) can't believe I even thought of or wrote that ! I see nothing wrong with dropping a chunk of coal in with your load of wood to help make sure it is still going when you get back to it, just don't think it would be safe with a cold mass.

heya... just some thoughts/ideas. i ve no experience in that.

get a CO-detector

i read that when the core of a stove is hot enough, then burning coals would produce enough oxygen to feed their own burn. you could test it by adding coals to a fire and tightly covering the feedtube when the flames are gone. you ll see the later, if there are coals left.

you could also cover the feed tube to reduce air-flow by 80-90%. if it still draws safely, then it might work. but test that on a day, not while you re asleep

could you transform that RMH to a batch rocket? would that make any sense?

good luck

tobias

Thank you for the information.  Yes, I assumed the stove would have to be hot and have a decent bed of hot coals from the wood to light the coal.  We use wood chips and dried grass to light the forges I work with.  Normally when I run my stove, you can't smell it outside.  It is super non polluting.  I will test the coal next month, when I have access to some.  

concerning electric heaters: have you seen this link? http://richsoil.com/electric-heat.jsp

it might help to have a thing just to heat the bed before sleeping. or to use a small amount of radiant heat where you are to help until stove is hot enough. the idea is to heat the person not the whole house.

Oh, we can heat the bed.  It is a heavy material bag of dried corn .  Chuck it in the microwave for 5 minutes, you are toasty all night.  However, it does nothing for the middle of the night potty run, or facing breakfast and coffee in a cold kitchen.  We are golden agers, getting cold hurts much worse now.

Kim Travis wrote:Oh, we can heat the bed.  It is a heavy material bag of dried corn .  Chuck it in the microwave for 5 minutes, you are toasty all night.  However, it does nothing for the middle of the night potty run, or facing breakfast and coffee in a cold kitchen.  We are golden agers, getting cold hurts much worse now.

You can use coal safely in a RMH for sure. I don't have a rocket stove, but I have burned lots of coal over the years. I say this with confidence because I know how coal burns and it lends itself well to rmh. That is because a coal fire needs two things to burn; coal and air. How intense the fire is, is controlled by how much coal is present and how much air is allowed to enter the coal bed. The more air, the hotter the fire in proportion to the amount of coal. In a rmh you would control the fire by how much coal was added, not so much in damping it down. Since the same amount of coal produces 1/3 longer burn times then the comparable amount of wood, you can easily see you just would need less coal to get a rmh to run properly since with coal, it is easy to overheat a home.

As a side note, I have burned coal in woodstoves that were never designed for it, but certainly the proper grates made maintaining the hot coal bed much easier. Now I am talking about anthracite coal here and not soft coal, but even the soft coal would work.