Rocket Mass Heater and Condensation

My first time posting here in this forum and My question is on exhaust and condensation from a Rock Mass Heater

I would like to use the existing chimney in the house [30' high][with clay liner]
due to the massive snow and high winds off the big lake going threw the wall with the vent looks like a bad idea for us
the has been used for the old wood cook stove,oil boiler [both removed now]
my concern is condensation in the chimney and the residuals from the previous equipment ending up in the basement and stinking up the house
grid down is the norm here and the Rocket Mass Heater looks like a better idea than a wood stove due to no electrical needs
currently we are running a wood pellet boiler,base board and a pre heater for domestic water .we have saved 70% on heating cost
another issue is the availability of wood pellets [got caught in the shortage this last heating season]
any thoughts or ideas

personal back ground

owned and operated a restaurant equipment repair business
custom built conveyor ovens at University of Michigan
commercial/industrial construction

Mike Hamilton

Hi mike; when it comes to chimneys , taller is always better and vertical beats horizontal every time. Big question is, what size is your chimney liner? It will determine what size rmh you can build. Do you have a copy of ianto evans RMH book ? It will answer a lot of questions you may have. You WILL get condensation from your rmh, especially during the drying process of your mass , as well as from wet wood. A good cleaning of the chimney before start up should help. After your mass is dry and if you burn seasoned wood most of the condensation will evaperate , leaving nothing but warm air coming out the chimney.

Mike Hamilton : Because this is an existing chimney with a history of mixed usage, I would definitely get a professional chimney sweep to take a look at it !

While a Rocket Mass Heater has a very low Exhaust gas discharge temperature, and is very forgiving of minor flaws in existing chimneys After the whole RMH
has gotten up to temperature, A Rocket Mass Heater , or any Heating Unit needs an intact, sealed Chimney to help draw the exhaust gases out of the House !

That Added to what Thomas Rubino says, and Ianto Evans' Great Book should make you a happy Rocketeer ! For the good of the Crafts ! BIG AL ,