Fireplace support for rocket mass?

I have recently bought a home that already has a fireplace with an insert and a woodstove on the main floor, and it has an unfinished basement. I plan on finishing the basement for a play area for my kids, and as a multiple use type room. In the near center of the basement is the brick column that support the existing fireplace above.

1) Would it be safe to use that as my mass, or would the repeated heatings cause problems?

2) Since it's a vertical mass, would the rocket stove be able to push the exhaust up the column and then out of the house?

3) And since I can't run the exhaust gas channels inside the existing column, how would I go about creating mass channels on the surface of the existing column?

Creighton S. : Welcome to our Rocket Stove area on Permies . Have you been to rocket stoves.com to get your Pdf copy $15.ooU.S. of Ianto Evans' great book
Rocket Mass Heaters ? I Will also recommend ernieanderica.info . Ernie W. and Erica W. are moderators for all Rocket stove threads here at Permies.

The basement location for a wood stove is problematic because the dragon that lives in your Rocket needs frequent feedings of smallish wood over 8 hrs to provide
20 -25 hrs of stored radiating heat ! Your plan for this area should include its use as an Adult recreation/entertainment, otherwise it will be out-of-sight - Out-of-mind .

You need to carefully look on all 4 sides of your basement brick column for an Ash pit or capped clean outs connecting directly with the back of, or floor of the
first floor fireplace. All flues found most be carefully checked for inside diameter, blockages,or cracked flue tiles. Any brick veneer must be regarded with a high degree
of suspicion and looked behind !

Failing to find any clean outs I would climb up on the roof and count the number of chimney flues you find in your chimney. Do i understand that you have located
two separate flues originating in your First floor living area, one for your fireplace and a second one for a wood stove ? ?

Not only will the brick column be great as a thermal mass, with a cement floor you can gain that as thermal mass too. You could literally wrap your thermal bench
around all 4 sides of the basement column, Additionally as part of a multi-media entertainment area you could create a two level area with light chairs located up on
the bench/thermal mass, with a more informal area on the lower floor level of your basement

A clever mason can easily carve a vertical chimney up through the basement brick column exiting at the back/floor area of your Fireplace adding clean out(s)
even saving your Fireplace to be converted later to a smaller more efficient "Rumsford Fireplace"

Moving smoke vertically is nothing, pushing hot exhaust horizontally is Pyro - magic !!!

Please feel free to search All the threads here in the rocket stove section as well as all of Permies, and also share your experience with this build.

Be Safe, stay Warm, Pyro Magically Big Al

allen lumley wrote:Creighton S. : Welcome to our Rocket Stove area on Permies . Have you been to rocket stoves.com to get your Pdf copy $15.ooU.S. of Ianto Evans' great book
Rocket Mass Heaters ?

Can I get it for Kindle?

The basement location for a wood stove is problematic because the dragon that lives in your Rocket needs frequent feedings of smallish wood over 8 hrs to provide
20 -25 hrs of stored radiating heat ! Your plan for this area should include its use as an Adult recreation/entertainment, otherwise it will be out-of-sight - Out-of-mind .

We homeschool, and the kids are never out of sight or out of mind. Either my wife, myself or one of my preteen children would be down there if the heater was in use; regardless of wether or not the small ones were down there or not. However, I'd need to make sure that the feed tube was "lockable" from my two tot boys. Girls seem to have sense enough to stay out of the dangerous stuff.

You need to carefully look on all 4 sides of your basement brick column for an Ash pit or capped clean outs connecting directly with the back of, or floor of the
first floor fireplace. All flues found most be carefully checked for inside diameter, blockages,or cracked flue tiles. Any brick veneer must be regarded with a high degree
of suspicion and looked behind !

I didn't even think about the possibility of using the clean out as a gas channel! I was thinking about wrapping the brick column with a layer of refractory cement and then a one or two brick layer gas channel facade, and then an exhaust out of the house at grade level. Wouldn't the gas be too cold to travel up the standard chimney?

Failing to find any clean outs I would climb up on the roof and count the number of chimney flues you find in your chimney. Do i understand that you have located
two separate flues originating in your First floor living area, one for your fireplace and a second one for a wood stove ? ?

The woodstove is in another part of the house, and does not share chimney space with the fireplace.

Not only will the brick column be great as a thermal mass, with a cement floor you can gain that as thermal mass too. You could literally wrap your thermal bench
around all 4 sides of the basement column, Additionally as part of a multi-media entertainment area you could create a two level area with light chairs located up on
the bench/thermal mass, with a more informal area on the lower floor level of your basement

Cool concept, but I don't have the ceiling height to do a two level floor. Wrapping the column with a bench is a great idea, though.

Creighton S. : Where do you live, its unlikely that with an internal chimney that you should have any problems in anything like normal operation, In the spring and fall
coming home from a 'trip away' you might find that the house is actually colder than the outdoors, in conditions like this getting the chimney to draw can challenge your
resourcefulness !

I don't do kindle, but if you find they do ,you should report that here !

I just can't seem to leave the idea of of two tier seating, by using a raised Thermal Mass bench you can use hassocks for foot rests which could be used for other seating !

This should be an interesting build, please continue to share here in Permies, Burning with wood is about as sustainable as you can get, but it can be very dirty, both in the
carry-in and out duties, you will want to keep the wood storage and the loading feeding and cleaning of the rocket out of the high traffic areas, allowing for the need to keep
an eye on the 'tots' !

You can't really 'close off' the top of the feed tube, but possibly something that is too heavy (without increasing the height of the feed tube) can be arranged with a counterweight.

GOOD LUCK ! Be Safe, keep Warm, Pyro magically - Big Al

allen lumley wrote:Creighton S. : Where do you live, its unlikely that with an internal chimney that you should have any problems in anything like normal operation, In the spring and fall
coming home from a 'trip away' you might find that the house is actually colder than the outdoors, in conditions like this getting the chimney to draw can challenge your
resourcefulness !

I live in Kentucky, but I wasn't talking about using the chimney for the exhaust of the rocket mass heater, that thought didn't even occur to me until it was mentioned by others. I was simply considering using the fireplace support column in the basement as the majority of my mass. I was also wondering how I could go about using that vertical mass and still push the exhaust up to the outdoor grade level and out of the house, when the RMH is going to be below the level of the exhaust vent by about 6-8 feet, and still extract 90% of the heat into the vertical column on the way.

I just can't seem to leave the idea of of two tier seating, by using a raised Thermal Mass bench you can use hassocks for foot rests which could be used for other seating !

Again, it's a great idea, but I don't have the ceiling height to do it. After all, it's a basement. If I were a foot taller, I'd have to stoop to avoid the lowest parts.

You can't really 'close off' the top of the feed tube, but possibly something that is too heavy (without increasing the height of the feed tube) can be arranged with a counterweight.

I'm not talking about a cover to keep them out of the running fire, although that would be a trick; I'm talking about a vent cap to keep them out of the ashes and mess when it's not in service. My two tot boys once got into the old coal ash of the fireplaces in our current house (haven't moved into the new place yet) and had an epic ash fight that literally had my wife screaming bloodly murder.