Thread: Damper Control

This is installed on a smaller Fisher wood stove. It is some type of damper control, but I have never seen one on a wood stove before. The stove is on the bottom of a two story house, if that makes any difference.

It appears to be some sort of self regulating damper. How would you use it or set it properly on the wood stove?

The label said it is a Conco Type RC Calibrated Draft Control.

Draft Control
This is very similar, although it is a different manufacturer.

These just don't seem to be used for wood burning appliances, from what I can tell.

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To set the damper you need to have a draft gauge inserted into the flue above the damper.

True they are not usually seen on wood burning appliances, but it is not a bad idea as long as they are adjusted properly, especially if the stove is the primary source of heat.
This website has a very detailed guide on inspecting barometric dampers.

How & Why to Open & Inspect Barometric Dampers & Draft Regulators on Oil Fired Heating Equipment

Jim, I don't see anything in the link you provided about the damper saying it is OK for use on wood stoves (but I admittedly didn't go beyond the front page of the site). And Dan's link for inspecting barometric dampers is in regard to oil-fired systems only.

Hmmmmmmm.....

Paging Bob Harper......paging Bob Harper....

This place had them in use on wood stoves.

Field Barometric Damper, Bacharach Meter, Key Dampers, Draft Hole Button

Not really sure how to adjust it or regulate it, but it doesn't look all that difficult. It looks like you'd need to get a typical fire going first, which of course we didn't have. There are no oil burners around here, so I'd never seen a setup like that.

Wood/Coal Stove Accessories - Barometric Draft Controls Fireplace, woodstove, chimney, parts & accessories - SandHill Wholesale

I would be inclined to see what the stove manufacture recommends. I have seen dampers on wood stoves.

I would tell them to remove it and have a proper elbow installed there.

Give that gizmo one long winter of wet wood burning, and the creosote buildup will create a dangerous situation there. IMO, a hazardous installation.

We used to put a 'damper' in the pipe on those old tin airtights, but they were a different animal, a movable flap inside the pipe to reduce the flow in the chimney.

Unless the presence of the baro. damper voids the warranty and listing, I would leave it in place but make sure it is adjusted properly. While not common with woodstoves, they are a good idea and even recommended by the National Comfort Institute's CO and Combustion cert. course. A baro. damper regulates the draft in the chimney. It prevents the stove from running away causing an unsafe high draft condition. Converesely, when the stack gases cool and begin to form creosote, the baro. damper closes so more heat from the appliance will warm the chimney an re-establish a reasonable draft. You need a manometer to set a baro., usually between -0.04to-0.06 inches of water column.
Aside from leveling out the burn cycle for a more predictable burn, the baro. instroduces dilution air to the stack, which can reduce creosote formation.

I try to add them whenever I can.


John, burning wet wood is a creosote hazard---not having a baro. damper. one of those links shows a typical stovepipe 'key' damper. These cannot block the flue more than 80%. They are removeable for sweeping and are used to reduce the flow--not draft.
If you go on Field Controls website and look under 'Draft' then type RC barometric dampers, it seems to refer only to oil. However, when you go to the section for product literature, the pdf clearly addresses using a type RC control for wood. I've used them for 25 years without a problem.

Note, on modern EPA phase II woodstoves, the use of a barometric damper will typically void the emissions certification. So will tall insulated listed liners. This is not a functional problem but merely points out the emissions cert. applies only under very special controlled conditions.

HTH,
Bob

Re: "not the same manufacturer" reference to field controls...well not exactly true (although wouldn't surprise me if Field Controls are mfg offshore/china now), they are the same, sort of (post acqusitions, etc.).

Field Controls LLC is the sucessor of Conco, Inc's Field Controls Division formerly of Mendota, IL [via Michael Heisley's (Heico) purchase purchase of the "Diversified Products Group of Conco, Inc." back in 79. ( Heico Cos. LLC sold off four divisions and kept Conco, Inc.'s Field Controls Division and the Spartan Tools Divison)], Field Controls LLC is held by Heico Cos Inc. via Heico Holdings (same Michael Heisley owner of the Memphis Griz btw).

Conco ref w/ or ws/o "field controls division" ref or a Mendota, IL ref would make it likely prior to 1977, if Kinston, NC ref. would be after. Heico bought Conco about 1979, I'm not sure if main operations for Field Controls Div had already transferred to NC before the acquisition or if that was closer to 87.

IIRC in the 70s those were referred to as "Field type R-C Draft Controls" not "RC" (note hyphen).

I thought I had some early 70s Field Controls Division, Conco, Inc. draft controls product sheets somewhere (Field Types AF, R-C, M, draft controls & Field draft inducers and duct boosters, circa 1973ish), but I couldn't find them, guess I purged them, sorry.

Acknowledged. Thanks, Bob.
Now can you ship me a couple of cords of that dry wood?

Just kidding. I'm on hydroelectric 100% nowadays. Firewood is up to $225/cord for city folks up here.


Barometric Dampers prevent appliance over- firing due to excess draft. They increase residence time of gases within the firebox, enhancing combustion. This means less creosote with wood fired appliances. Field barometric dampers represent the “State of the Art” in draft controls, featuring heavy duty construction with high sensitivity.
Precision calibrated at the factory for both
horizontal and vertical installation. The controls to the right are designed for use where a TEE is provided.

As Bob points out "Note, on modern EPA phase II woodstoves, the use of a barometric damper will typically void the emissions certification." and would also void the listing (as in not installed per instructions) for all of the phase II stoves and fireplaces I am familiar with.
In line damper are used in tall chimney situations if needed, but the new stoves are designed to work within a range (changeing with conditions) of draft.

I think with a barometric damper, if you had a chimney fire the damper would open and help you clean out the pesky build up of creosote </sarcasm>

All that said, looking at the picture the single wall barometric damper that is part of the chimney, looks way too close to the wall, is it more than 18"? Or do the instructions/listing of the stove/chimney allow it to be closer?

My 2c

HI EVERYBODY!!!
NEW TO THIS FORUM,BUT I THINK THAT YOU CAN REALLY HELP ME!I'M INSTALLING A AUTOCRAT AMERICANA MODEL#FH76 WOOD STOVE THAT I'VE HAD FOR 20 YRS OR MORE[NEVER USED].MY PROBLEM IS AUTOCRAT IS OUT OF BUSSINESS AND I'M TRYING TO FIND A PART FOR THE FIELD TYPE R-C CALIBRATED BAROMETRIC DRAFT CONTROL'THE PART IS THE ADJUSTING WEIGHT,WHICH HAS BEEN MISSING FOR EVER.IF I CAN FIND OUT THE "WEIGHT" OF SAID ADJ WT. .I'LL IMPROVISE
THANKS FOR THE HELP
MIKE

Originally Posted by mike sweet

HI EVERYBODY!!!
NEW TO THIS FORUM,BUT I THINK THAT YOU CAN REALLY HELP ME!I'M INSTALLING A AUTOCRAT AMERICANA MODEL#FH76 WOOD STOVE THAT I'VE HAD FOR 20 YRS OR MORE[NEVER USED].MY PROBLEM IS AUTOCRAT IS OUT OF BUSSINESS AND I'M TRYING TO FIND A PART FOR THE FIELD TYPE R-C CALIBRATED BAROMETRIC DRAFT CONTROL'THE PART IS THE ADJUSTING WEIGHT,WHICH HAS BEEN MISSING FOR EVER.IF I CAN FIND OUT THE "WEIGHT" OF SAID ADJ WT. .I'LL IMPROVISE
THANKS FOR THE HELP
MIKE

Mike, did you ever find any parts for your Autocrat stove? I have the same model over 25 years. Still have the operators manual with part numbers. Mine has the blower on the back with the Conco RC damper control. Still really don't know how to set that thing. I NEVER open the draft door in the ash pan because it lets the firebox get too hot. I have to keep it closed all the time. I have to do the fire regulation with the damper. The doors are sealed good and so is the ash box, so not sure why it gets so hot. My 8" metal chimney goes straight to the roof about probably about 22ft. There is a tee above the stove with the RC control. I always burn at least 1 year old seasoned wood, mostly ash, oak, and maybe a piece of bodock. I may need a new temp control on the ash box, not sure if that's the problem, but don't know what else to look at.