First off, hello everyone just registered today. OK here goes. I live in a mobile home and would really like to know if I could
1) build and use a RMH within my home? (the home is very solid and very well insulated)
2) if I can do this could I vent it through my existing chimney so I would not have to create another exit hole from the interior?
The fireplace heats the immediate area decent but the rooms at the ends of the home remain quite cold, especially when temperatures get down below 30 outside. We are exploring possiblities to eliminate the huge gas bill we have (gas is on the rise, Price wise)
I sure could use some information from some of you who definitely have much more experience in these matters than me.
3) would some sort of RMH ; if able to build in my mobile home and use existing chimney to vent... would or could this heat most if not all the house?

Any help would be appreciated...thank you all

Design concerns aside, first and foremost I'd make sure you've got sufficient insulation at the ends of the home.  Walls, ceilings, and floors, and windows.

no offense... but I kinda suspect that building an RMH into even a stationary MH is what the greybeards in my neck of the woods might call "chroming a turd"...

if you own, look into building something- anything- which the RMH can integrate into. and that will possibly require all your local permiting issues to be faced. some places that's not an issue. others it is.

however, even if you own and just want to put it in for the comfort, you will run into so many hangups trying to make it all fit and be safe that you may as well start from scratch. I haven't seen your MH, but Ive also never seen one in which, to build a proper RMH, the floor and a wall wouldn't have to be cut up and rebuilt. In MH's that is a real crappy job to do that never ends up feeling right.

Now, building a greenhouse and heating that - and aquaponics -with the RMH, as auxillary heat for the MH, that might be completely different. You'll end up moving into the greenhouse.

well first off I am offended.
secondly i can almost 100% bet this home is more solid than typical homes most people live in.
Not one of my F'ing questions  was answered...is this forum also just another place where assholes ad unmannered people get to talk crap hidden behind their computer screens anonymously. Damn I should have known...whats this guys age? or did he just never learn to read a question and if you have an answer answer it if not shut your fat mouth.

I can not believe the gaul of this guy

that post was based on Deston's previous experience with mobile homes.  I don't believe it was a value judgment about you or your home.  to get this back on track, how about you talk a little bit more about the specific mobile home in question.  what makes it so solid?  what have you or the manufacturer done to make it more energy efficient than other models?  what are the dimensions of the room you would like to put a mass heater in?  things along those lines.

tommy south, hold yer hat. I did answer your questions. just not the way you wanted. Im 40, if it matters, and I have torn apart no less than a dozen mobile homes, and repaired various portions of several others besides. Have one that just went to salvage and another on the way in the yard.

You can be offended, I wont tell ya what to do. heres my thoughts that led to the short answer about chroming turds.

1) build and use a RMH within my home? (the home is very solid and very well insulated)

sure. you could. If you wanted to go through a lot more headache than necessary. the building styles are almost incompatible, making materials, joinery and sealing problematic. You'd have to remove walls and probably some floor- an RMH wont seat on the floor of an MH - it weights a several tons. frames of mobile homes Ive seen arent made for this weight, so it would require shoring or removal of floor.  if you were talking >ROCKET STOVE< and not a mass heater, that would be potentially doable, but you didnt say rocket stove.

2) if I can do this could I vent it through my existing chimney so I would not have to create another exit hole from the interior?

Probably not. Id have to look at your specific design, best thing to do is take a bunch of measurements and read the book. your exhaust pipe length and rise are limited by the size of your burn assembly volume. Id wager the vertical exhaust after the heat transfer would not allow the exhaust out and you would loose significant draft if not just put the fire out. again, rocket stove, a completely different story.

3) would some sort of RMH ; if able to build in my mobile home and use existing chimney to vent... would or could this heat most if not all the house?

it would not heat most of the house. it would even the heated period out, but if your current stove isnt doing it, the RMH wont, unless its HUGE. huge is more demolition and rebuild issues with incompatible materials. I suspect you lack insulation. Even Modern MH use r18 at best on stock in my area, region 7. what it will do is create nice warm pad or bench or floor area that has consistent warmth and low input. very nice for sleeping on, morning coffee, etc. but its a local heat, radiant. youd have to have circulation to get it to the back rooms.

technical note: cob weighs about 120#/sf. a cubic yard weighs @3240. most RHM use at least 2 yards material; Ive seen ones with 5.  typical area is about 3-6sq/yards. if you can put 7500# on 50sf of your floor (or shore it so you can) you still have the mess of the construction in the home and the problem of venting through a wall if your vertical exhaust exhaust wont handle the flows.... again, Id consult the book and do the math.

all that considered, I'd suggest you to build a green house auxiliary heater with an RMH if your code situation allows. you could pipe the exhaust under the house in a exchanger, and seal it to uninsulated floor, thus heating up through the floor as well as through vents from the GH.

theres alot of background info that you dont provide, and alot you dont have. I reckon I can say that cause Ive been doing this for about 20 years and im just starting to have a clue about those damn turds. Ive chromed a few myself.

Tommy, Deston is an extremely experienced cob maker, natural builder, and salvaged-material redneck-remodeler extraordinaire.  His delivery might have been a little rough, but he means well.  He gave us some really key advice to help our RMH become a functioning reality and not just a dream.  We didn't listen to ALL of his advice....but a lot of it was right on.  If he ends up being right about the stuff we decided to ignore, it will be egg on our face and another feather in his hat.  He doesn't like to see people fail, though, cause he knows how much it sucks to work really hard on something and then......

I too have a hard time imagining a mobile home that is sturdy enough to handle the the several tons of thermal mass to which a rocket stove must be connected in order to be an effective heating device.  And yeah, integrating natural building materials and techniques into a manufactured home - built with seriously opposing ideas and materials -- will be challenging.  It might not be impossible, but it might be a lessor headache to build an entirely different structure out of analogous materials. 

thank you.  I look forward to finding out what is learned on your project. it is remarkable.

I am trying to design it but  i have a query, when initially starting the fire, smoke might not draw through the system until the burning chamber is heated, so does any one have this kind of design to avoid this problem?

Ricky, are you following the design perimeters in the Rocket Mass heater book? Ive worked on a couple RMH's and aside from a small puff of smoke at ignition, heaters ive seen draft to the side after a matter of a few seconds. that puff of smooke may be annoying if the ignition is in the main home, tho most RMH designs Ive seen place the ignition/feed either outside or in a vestibule. Im considering building one in my bathhouse with the ignition feed inside, and to that end Im toying with some design alternatives-  that said, Im reading the code and the book extensively on account this RMH behaves very differently than a normal woodstove and modifying any element of its system  will tweak performance- and possibly safety (especially if tweaks are at the burn end). I dont plan on building mine until late in the summer. if you do get any notions post away before building. Ill hope I come off as a yokel rather than offensive. I dont mean to run anyone off with my jibber jabber. theres a pretty solid core of folks here who've built and live with these things, and youll get about the best experiential advise one can get. cheers.