Barometric Grandma baffle question

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SEEL814u

Member
Sep 30, 2015
2
Sierras, CA.
I think you are referring to the air intake box located within the top vent. It is a separation between exhaust and rear intake for barometric damper. No catalyst and no smoke passed through it. It is simply an air intake for chimney to control excessive draft by introducing cooler air into chimney, the same way a T would do on a barometric damper. This is not a barometric stove. They were on some model III's after 1980 shown below;

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Coaly & all
Thanks for all the VERY useful info here --- I apparently have (in the 1982 house I bought) one of those Model III's you speak of & show. It is a free standing, top-exhaust, rear-damper Grandma. I'm new to the site & wood heating as well.
(Damper is stubbed out the back, behind the (shown) box, of this top vent unit) I would like to: 1) cut side fire-bricks on an angel (?*?); 2) notch a baffle plate around the vent-box on top of those (angled) bricks; 3) insert plate below the existing brick-top-retainers (w/brick retainer angles on plate). 4) Notch the leading edge corners of the plate by 3" in & 2" back.
A) Do you foresee any problems with this? B) How snuggly would the plate need to be cut to fit around the box? C) Any added fire-brick or support or seal needed at rear? D) Good or bad effects to stove or material function? E) Should a "skirt" be welded around the notch on the plate and across the "skirt" bottom to shield the vent-box from excess heat?
Help please! Wife wants NEW $$$$ stove, & if this baffle addition presents a hassle SHE'LL HAVE HER WAY WITH ME (again)!! HA ---
Stove is down for "chimney" repairs at present, so need to decide "repair or replace" ASAP --- Thanks in advance for ANY INFO.
Hope this helps others as well, who have maybe "NEVER BEEN HERE, DONE THAT" ---

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Yes, that is a Barometric Stove, with barometric separation box. I assume the rear opening for barometric damper is capped off?

Yes, simply notch the baffle at rear to fit around the box. A tight fit isn't necessary.
When the top row of bricks are there, it makes baffle installation more difficult. Without those, I simply set bricks on edge to rest baffle on near the front.
I would make a cardboard template first, notch it for the box, or go under it, then notch sides to set on upper bricks. You may have to cut a new brick lengthwise to set on the rear shelf to support plate across rear. "Aim" the template for the bend in stove top. This will give you the plate size for angle chosen. Make sure the square inch opening (smoke space) is at least as large as flue square inch area. Keep the space larger than minimum and it can be adjusted later by raising baffle. Another reason to keep the fit loose with about 1/8 inch clearance all the way around. 5/16 thick material is best for your width.

Here are two threads pertaining to what you're doing if you haven't seen them; The second thread has video of completed baffle in use on page 2.
https://www.hearth.com/talk/threads...d-fisher-more-heat-less-smoke-under-25.74710/
https://www.hearth.com/talk/threads/cant-seem-to-figure-out.119184/
 
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