Installing an insert without using 6" flue liner tube because of my chimney's heat exchanger system

[laxin213]

Hello,

Have been looking at a few larger inserts and narrowed it to a 5100i, a Clydesdale and Merrimack for the house I moved into about a year ago... Anyways, I had a local stove shop out for an estimate and he was a bit taken aback at my heat exchanger above the firebox in my existing fireplace. He said that he needs to speak with the manufacturer and also consult with another guy at his company, as he has never seen this chimney configuration. He's saying "this was a very specialized type of chimney and clearly when you look at the chimney, it wasn't built by a couple of teenagers in a weekend, these were knowledgeable masons that were building this chimeny with a specific idea in mind with the best technology they had in that time". (1984 was when my house was built)...

He's thinking my options are:

1. Having them demo around 4' of the cinder block style narrow 9"x3" heat exchanger tubes that were basically designed to make the large (8' wide by 3.5' deep) center house chimney a heat bank. He's saying it would be very difficult to demo out the material. Then run the 6" flue liner and install an insert.

2. Install an insert with a couple feet of 6" liner then build a pan that sits right below the "heat exchanger" and just have the insert then use the existing chimney and go out the top, not in a liner.

3. Scrap the insert all together and just burn wood in the fireplace and try for some sort of firebox or hearth blower.

I have shown several area stove shops the same picture as I'm adding below. 2 of them said we'll just demo it out and install a liner. He is the only one to come out and from what he can measure its about 4' tall. He did point out to me an opening in my fireplace that I always thought was an ash dump and I never used it - no it's actually connected to a pipe that provides outside air to the fireplace for drafting... Didn't know that. Its hard moving into a house and understanding all the systems, especially when the previous owner didn't know or explain them to me....Thanks for any input or knowledge on this type of fireplace system that I have.

 

[begreen]

Yup, it's a nasty sawzall, grinder or cutting torch job. But it only needs to be done once. Maybe only one section needs to be cut out to get clearance for a 6" liner. With the right tools and approach it shouldn't take more than a couple hours.

Slammer installs are no longer legal, not an option.

Option #2 would be to extend the hearth and put a freestanding, top vent stove on it. Then tap into the new liner above the heat exchanger.

Get a second and third opinion from certified installers.

http://www.nficertified.org/pages_consumers/consumers-4.html
www.csia.org

 

[Simonkenton]

As far as scrapping the wood stove, and just burning the fireplace, with its sophisticated heat exchanger, I can speak to that. I built the fireplace pictured to the left. This fireplace is the best heating fireplace that I have ever used. It is the Rumford style fire box, so it maximized radiant heat thrown into the room, while the fire is burning. We had set the sofa 7 feet from the fireplace, had to move it back to 10 feet because we were getting roasted!
This fireplace does not have a heat exchanger, although, I did look into installing one, decided it was just too complicated. However, the fireplace sets entirely within the house. The back wall of the fireplace is the inside wall of the bathroom.
If you burn the fireplace for 5 hours, that back wall heats up to about 106 degrees. That doesn't seem very hot, but, you have 5 tons of masonry at that temp. You let the fire go out, close the damper, and the fireplace will throw good heat for 24 hours, and more.
Burning the fireplace for 5 hours, you can heat my entire house with it on a 32 degree night.

As good a heater as my fireplace is, it is nowhere near as efficient as a wood stove. My little old Waterford stove will heat the house better than the fireplace, using about 1/5 as much firewood.

If I were you I would forget the fireplace and run a liner up the chimney for the wood stove.
On the other hand, have you tried heating your house with the fireplace? If that fireplace is entirely within the house, as mine is, it might be a great heater! That mason went to a lot of trouble to install that heat exchanger.
Let me ask you this. Your firebox looks like a Rumford. Examine the vertical walls of the firebox. Do they go straight up, or are they angled in towards the living room?
If those firebox walls angle in, maybe 7 inches, then you have a Rumford. There were very few masons building Rumford fire boxes in 1984, if you have one, then you really have a sophisticated fireplace.
Could you put a free standing stove elsewhere in the house?

 

[laxin213]

Thanks for the replies - meant to follow up on this. Got an insert and found a certified CSIA guy at a local stove shop. the firebox walls of the fireplace were barely tilted, and I don't think I had a Rumford. Too bad would have been neat. Thanks for the insight.