Rocket Mass heater installation road blocks

Located in Colorado.
Home built in 1980's with a wood stove and this chimney/exhaust system. It was used but i dont know the extent of the 30 year use.

We removed the wood burning stove as well as all the broken, rusted sleeve/elbow attachments that were here. We tiled the interior back wall and were preparing to create the ground/foundation/base for our new Liberator Rocket Mass Heater when we received negative feedback from a few contractors.

Apparently this "chimney" is non standard and is being described to me as unsafe to connect to with my new RMH. Idk if these individuals are not familiar with RMH and how they operate or if my idea is a just a pipe dream.

I am attaching 4 pics.
1 of the heater itself
1of the interior space where it will be installed
2 of the exterior pipe

I am aware there are a few connection pieces missing from the pipe to house (exterior) and interior wall to the RMH.
However, in the event we obtained the proper pieces to put this together, is this chimney pipe able to be utilized for our exhaust vent from the RMH or do we need to start over with something different?

Appreciate all of your input/feedback.

Wow, that is an awesomely beefy looking chimney!  What is the approximate inside and outside diameter of that chimney pipe?  What size chimney pipe exits the Liberator RMH?  

R Parian wrote:Wow, that is an awesomely beefy looking chimney!  What is the approximate inside and outside diameter of that chimney pipe?  What size chimney pipe exits the Liberator RMH?  

Its unique for sure 🙃

Liberator appears to be 6" exit/exhaust

Exterior: cast iron/steel pipe appears to be have "tyler union water works" markings and was referred to by 1 guy as a drain pipe?
Seems to be 8" possibly? Havent measured but it says 8x8 on the pipe exterior.

There is extreme creosote build up noticed but no one will clean it. We will attempt ourselves if need be but i dont want to waste time and energy if this thing needs to go.

Hi Sara; Welcome to Permies!

Sadly Sara I think it needs to go.
If you were burning a box stove and letting high heat escape up the chimney then this pipe would do fine. It will never burn out and a chimney fire won't hurt it.
Why it won't work well with your liberator, is your exhaust is to cool.
That heavy steel pipe would condensate heavily and never warm up.  If it can't warm up then it will not draw.
No draw, then it smokes back into your house...

What you really need with an outside chimney like that, is insulated stove pipe.
It is the only way you will keep a steady draw going.

I see Thomas has posted on this, and he's the RMH guru, and I think he's right. But I'm gonna post my musings anyway.

===

Oh, wow. As far as improvised setups go, this rings the bell. Awesome! Hair-raising! And problematic. But one helluva conversation piece! Random thoughts:

This was never built to Code, and never will be. Yes, it is cast iron sewer pipe. Somebody must have had a source for cheap. Yes, you can clean it yourself, and you should do so right away; it's not hard, and I suspect a chimney fire may cause it to crumble. It's critical that the brackets holding this thing to the house are mega strong and massively anchored (inspect and reinforce!), If it ever falls, it will terminate everything and everyone in its path.

A tall, cold, uninsulated pipe will be a bit of a pain when it comes to starting your heater, or any wood stove. There is a big slug of cold air just waiting to drain into your stove and house, pushing the smoke into the living room.

The part that worries me (and your contractors as well, I'll wager) is the through-the-wall section of pipe. It's lightly insulated, but old, and was obviously another inprovised installation. This is the bit that will burn your house down. Mind the asbestos risk if the pipe wall has been breeched anywhere. I would seriously consider buying an engineered pipe system for this part; this is not the place to economize.

Probably, it all comes down to insurance: will your provider sign off on this as a 'grandfathered chimney thingy?' I think the exterior chimney is usable and not a significant hazard. I'm not sure they will agree.

If you don't keep it, post it on Craigslist or whatever. Somebody will want this thing for their garage, cabin, or other outbuilding, because it's awesome. I know I would.

My 2c.

thomas rubino wrote:Hi Sara; Welcome to Permies!

Sadly Sara I think it needs to go.
If you were burning a box stove and letting high heat escape up the chimney then this pipe would do fine. It will never burn out and a chimney fire won't hurt it.
Why it won't work well with your liberator, is your exhaust is to cool.
That heavy steel pipe would condensate heavily and never warm up.  If it can't warm up then it will not draw.
No draw, then it smokes back into your house...

What you really need with an outside chimney like that, is insulated stove pipe.
It is the only way you will keep a steady draw going.

Thank you!
My husband is curious if a flue liner in this thing would help?

Douglas Alpenstock wrote:I see Thomas has posted on this, and he's the RMH guru, and I think he's right. But I'm gonna post my musings anyway.

===

Oh, wow. As far as improvised setups go, this rings the bell. Awesome! Hair-raising! And problematic. But one helluva conversation piece! Random thoughts:

This was never built to Code, and never will be. Yes, it is cast iron sewer pipe. Somebody must have had a source for cheap. Yes, you can clean it yourself, and you should do so right away; it's not hard, and I suspect a chimney fire may cause it to crumble. It's critical that the brackets holding this thing to the house are mega strong and massively anchored (inspect and reinforce!), If it ever falls, it will terminate everything and everyone in its path.

A tall, cold, uninsulated pipe will be a bit of a pain when it comes to starting your heater, or any wood stove. There is a big slug of cold air just waiting to drain into your stove and house, pushing the smoke into the living room.

The part that worries me (and your contractors as well, I'll wager) is the through-the-wall section of pipe. It's lightly insulated, but old, and was obviously another inprovised installation. This is the bit that will burn your house down. Mind the asbestos risk if the pipe wall has been breeched anywhere. I would seriously consider buying an engineered pipe system for this part; this is not the place to economize.

Probably, it all comes down to insurance: will your provider sign off on this as a 'grandfathered chimney thingy?' I think the exterior chimney is usable and not a significant hazard. I'm not sure they will agree.

If you don't keep it, post it on Craigslist or whatever. Somebody will want this thing for their garage, cabin, or other outbuilding, because it's awesome. I know I would.

My 2c.

Thank you!
My husband wants to know if a flue liner would work in this?

Also, i was shocked at the simple hole in the wall pipe. How in the world can i correct this for safety?"

Hi Sara;
No, it is just not large enough.  A liner inside your cast pipe will not help, it would still stay cold and condensate/creosote until plugged.
You must have an insulated pipe that stays warm when your stove is running.
You commented that it is already heavily creosoted.  This is  a result of it not being hot enough even with the box stove the previous owner was using.
A good working RMH never has exhaust much over 200F. If you try to run one without a good draw you will quickly fill your house with smoke.

Your thru the wall piece needs to be upgraded to a "metalbestos" insulated pipe as well.
From what I can see it looks like the previous owner would build a stick fire in the large housing at the bottom of the cast pipe.
This of course would ignite the creosote, creating a tall candle that no doubt had a heck of a flame shooting out the top.

The best thing for you to do is install a proper chimney. A cement block chimney with liner would be my recommendation, or an all "metalbestos" insulated chimney.
Neither will be cheap but both would be safe and last a lifetime.

thomas rubino wrote:Hi Sara;
No, it is just not large enough.  A liner inside your cast pipe will not help, it would still stay cold and condensate/creosote until plugged.
You must have an insulated pipe that stays warm when your stove is running.
You commented that it is already heavily creosoted.  This is  a result of it not being hot enough even with the box stove the previous owner was using.
A good working RMH never has exhaust much over 200F. If you try to run one without a good draw you will quickly fill your house with smoke.

Your thru the wall piece needs to be upgraded to a "metalbestos" insulated pipe as well.
From what I can see it looks like the previous owner would build a stick fire in the large housing at the bottom of the cast pipe.
This of course would ignite the creosote, creating a tall candle that no doubt had a heck of a flame shooting out the top.

The best thing for you to do is install a proper chimney. A cement block chimney with liner would be my recommendation, or an all "metalbestos" insulated chimney.
Neither will be cheap but both would be safe and last a lifetime.

Got it! I appreciate your detailed reply. Thank you for sharing your knowledge. I forwarded to my husband as well so we can do this properly.