Damper discussion

[9Fingers]

Greetings to all, new guy and my first post. I've been searching the site but don't see many references regarding dampers in the stove pipe.

We put in a Quadrafire Cumberland Gap 5 years ago. Until then it was all oil fired base board hot water heat. Fuel prices drove the install decision. There was no mention in any of the literature about installing a damper. Chimney is a stainless double wall above the ceiling and black iron double wall from stove to ceiling fitting. Since it was not listed or discussed, we did not install one.

House is 2200 sf and so far, we've been using 5-6 full cord per year to supply 80-85% of our home heating. House design requires blowing the air from the stove room in to the other side of the house. It's worked pretty well so far.

I guess my question is are dampers optional or a must have item in ALL installations. I welcome your observations.

Ken

 

[HotCoals]

If your fire can be tamed with your intake air you should be fine.
I have a damper on mine put don't really need it.

 

[bholler]

it is generally not recommended with new stoves. But if you have excessive draft you might need one to control the fire.

 

[9Fingers]

We've had no trouble controlling it really. I'm not getting the long burning time they claim in the literature, such as 7-9 hours. About 5-5 1/2 is about as good as it gets. The getting up at 2-3 AM gets old after a while but better that then writing a bigger check to the oil man. I thought perhaps the damper would boost the burn time or perhaps that was how they got their longer burn times.

 

[HotCoals]

We've had no trouble controlling it really. I'm not getting the long burning time they claim in the literature, such as 7-9 hours. About 5-5 1/2 is about as good as it gets. The getting up at 2-3 AM gets old after a while but better that then writing a bigger check to the oil man. I thought perhaps the damper would boost the burn time or perhaps that was how they got their longer burn times.

Well check your gaskets because you should get longer burns then that.
Can you turn the air down and have the fire almost go out or do you still have considerable flame yet?

 

[Grisu]

Burn time does not mean you will have a fire for 8 to 10 hours. Most people here define burn time as the time between loading and still having enough coals left for an easy reload while some heat is still coming from the stove. Since there is no "official" definition, manufacturers can write pretty much anything.

Just a hunch but heating 2200 sqft using 5 to 6 cords of wood indicates you are pushing your stove pretty hard. The Gap is just a larger mid-size stove with a 2.4 cu ft firebox. When you need to get up in the middle of the night to feed it, I suspect it is undersized for your heating needs. You may need something larger with a firebox of more than 3 cu ft. That aside, what stovetop temps do you see? How long has your wood been seasoned by stacking it in a sunny and windy location?

 

[9Fingers]

Gaskets: replaced the side door gasket last year. Front doors only opened for cleaning out, run with doors shut all the time. Shutting the air intake slider down will shut the fire right down, will take it from a lively flame situation to a barely burning - just alive fire - quickly so I think they are OK.
In general, I burn white ash, red oak, swamp and sugar maple with a sprinkling of cherry. Wood is seasoned ahead a year, stacked on a steel rack with air space under and between rows, cut 16-18", depending on the round I had to work with. Those pieces in my avatar are nearly 36" in diameter, oak; broke them down with a hammer and wedge to pieces I could handle to lift on to the splitter. They've been stacked in the larger pieces since March of 2013, they'll be in line for the stove sometime in January 2015 and beyond. I looked at them today, in fact and the ends are checking nicely as is. They'll be broke down to final size by mid April and in the racks at home by May 1. I try for a max size for both drying and packing in the stove of 5 x4 inch when viewed end on. The door is kinda small and once you get a few pieces in you don't have a lot of room to maneuver the others.

As for temps, I have no indicators of any kind other than what I see through the doors.

I guess I considered the burn time as actually still having a decent amount of coals versus residual heat. Usually, no problem in adding more wood, opening it up for a few minutes until it will hold flame when turned down and back to bed. Didn't mean to give the impression that the stove was out or anything.

Stove was chosen by my wife 'cause she liked the way it looked and matched the square footage of the house; I wanted to oversize but got over-ruled...
Remember, when Mama's happy, the house is happy.

 

[Grisu]

It looks like your wood is not dry enough. That the ends are showing cracks does not mean the inside is dry. Most hardwoods need 2 years to season, oak can be up to 3. The time they are sitting in unsplit rounds does not really count; the seasoning will be negligible. I would suggest to get at least 2 years ahead meaning you should be splitting and stacking the wood for the winter 2015/16 now. The fact that the fire goes almost out when you turn down the air is most likely also a sign that your wood is not dry enough. You should see flames in the top of your firebox and no smoke coming out your chimney. A stovetop thermometer would help in determining whether you even get the stove hot enough. What kind of chimney do you have and how tall is it?

 

[firefighterjake]

As mentioned regarding the damper ... depends largely on the draft. In the few years I've been running my epa stove the only time I thought I could have used a damper for better control and a bit longer burn was when I loaded the stove with a mix of oak, beech and black locusts ... otherwise the stove works pretty well without the damper.

 

[9Fingers]

I'm absolutely getting fire in the top of the box, no smoke from the chimney except on reloading. Usually run the control at 1/4 to 1/3 open to get full combustion, but at that rate it won't maintain a high enough temp in the house. Best output during the day with my wife at home (she works from home) comes at 1/2 way or a bit above. Obviously, the BTU output is higher at 1/2 way rather than 1/4 way open.

Chimney is 6", stainless double wall, in an enclosed chase built bigger than code requires for clearance; I don't remember the exact vertical run but its in the area of 28-30' to clear the roof peaks. Have no problem with lighting up or back drafts when opening the side door for loading.

I get my wood from cleaning up after logging operations locally, taking the tops they left behind or standing dead or blow-downs, so I'm not cutting live standing trees.

We have the chimney cleaned every year and our guy always comments on how clean this stove burns compared to others that he services regularly.

 

[smokedragon]

it is generally not recommended with new stoves. But if you have excessive draft you might need one to control the fire.

+ 1 to this.

You aren't supposed to need/use one in newer stoves. But there are multiple forums on here about runaway stoves that just gobble up wood and burn too hot......as soon as those owners put in key dampers, problem solved.

If you can control your stove, no need.

 

[smokedragon]

I'm absolutely getting fire in the top of the box, no smoke from the chimney except on reloading. Usually run the control at 1/4 to 1/3 open to get full combustion, but at that rate it won't maintain a high enough temp in the house. Best output during the day with my wife at home (she works from home) comes at 1/2 way or a bit above. Obviously, the BTU output is higher at 1/2 way rather than 1/4 way open.

Other than your wood moisture (buy a moisture meter, best investment you can make)......people say it takes X long to season Y wood. The only way to really know is to split a bigger chunk and measure on the freshly split face.

Try burning with ECO bricks or BIO brick (compressed wood product). If the stove burns noticeably hotter, your wood could well be what is causing this.

If the wood is really dry, then your post above leads me to think your stove is undersized.

 

[Grisu]

I'm absolutely getting fire in the top of the box, no smoke from the chimney except on reloading. Usually run the control at 1/4 to 1/3 open to get full combustion, but at that rate it won't maintain a high enough temp in the house. Best output during the day with my wife at home (she works from home) comes at 1/2 way or a bit above. Obviously, the BTU output is higher at 1/2 way rather than 1/4 way open.

Chimney is 6", stainless double wall, in an enclosed chase built bigger than code requires for clearance; I don't remember the exact vertical run but its in the area of 28-30' to clear the roof peaks. Have no problem with lighting up or back drafts when opening the side door for loading.

I get my wood from cleaning up after logging operations locally, taking the tops they left behind or standing dead or blow-downs, so I'm not cutting live standing trees.

We have the chimney cleaned every year and our guy always comments on how clean this stove burns compared to others that he services regularly.

That's a tall stack and you should not have any draft problems. However, it looks like you need to keep the air pretty wide open in order to get the stove to heat. With that you will lose quite a bit of heat up the flue explaining the short burn times. It's up to you but when you want to stop getting up in the middle of the night I would highly recommend to dry your wood for two years (or try the Ecobricks). Once you load that stove with nice dry oak and pretty much close the air while maintaining nice secondaries you should easily get 8 to 10 hours of good heat. I have a different, slightly smaller stove but when I load it with nice dry ash I can get the top to ~725 F and still get an overnight burn of up to 10 hours by closing the air completely.

I second the suggestion of a moisture meter. Here is a cheap one: http://www.harborfreight.com/digital-mini-moisture-meter-67143.html
Split a few pieces and press the pins in the center of the fresh surface along the grain. It should read 20% or less. Dead trees can be drier than green ones but that is not a given. Especially the trunk can still hold a lot of water.

I also would recommend a stovetop thermometer. Right now you don't know how well you are actually burning. With the air that wide open it could be that you are unknowingly overfiring your stove. Condar thermometers are well liked here or try an IR thermometer like that: http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-69465-8905.html

 

[ailanthus]

I have a damper and use it all the time. With strong draft it can give you more controllable/longer heat output.

Dry wood should be the first concern, as others have said.

 

[Grisu]

I have a damper and use it all the time. With strong draft it can give you more controllable/longer heat output.

Just to clarify: A damper is an option for someone who closes the primary air all the way down and still gets a runaway fire. That suggests the draft is too strong. However, the OP burns his wood with the air 1/4 to 1/2 open, so excessive draft is not the problem.

Dry wood should be the first concern, as others have said.

Cannot be said often enough.

 

[ailanthus]

Just to clarify: A damper is an option for someone who closes the primary air all the way down and still gets a runaway fire. That suggests the draft is too strong. However, the OP burns his wood with the air 1/4 to 1/2 open, so excessive draft is not the problem.

This may be different for different stoves, and this probably doesnt apply to the OP, but I cant turn my primary completely shut or my secondaries will kind of blow themselves out from such high airflow. I need some minimal primary flame to ignite the gasses at any temperature. Id be interested in knowing if other castine owners experience the same thing, but after reaching a stovetop temp of 500+, my best burns are with the pipe damper 75% closed and the primary air at ~25%. 30 year old locust so it's not the wood

 

[begreen]

There are a lot of variables controlling draft in an installation. So many that together with woodstove differences it makes almost every installation unique.

Locust is a dense wood. It needs a bit more air in the T6 until it is burning strongly. It did in the Castine as well. Our splits are fairly thick. If I recall I had to run it about 1/4 open, with no stove pipe damper on our 20' flue system. Burning doug fir the air control on both stoves would be closed.

 

[smokedragon]

I second the suggestion of a moisture meter. Here is a cheap one: http://www.harborfreight.com/digital-mini-moisture-meter-67143.html
Split a few pieces and press the pins in the center of the fresh surface along the grain. It should read 20% or less. Dead trees can be drier than green ones but that is not a given. Especially the trunk can still hold a lot of water.
I also would recommend a stovetop thermometer. Right now you don't know how well you are actually burning. With the air that wide open it could be that you are unknowingly overfiring your stove. Condar thermometers are well liked here or try an IR thermometer like that: http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-69465-8905.html

I highly advise against that HF moisture meter, cause it takes very special batteries. For a little more, you can get one that takes a 9V (www.lowes.com)

I have gotten some great little tools at HF for a great price, but that one isn't one of them.

 

[Grisu]

I highly advise against that HF moisture meter, cause it takes very special batteries. For a little more, you can get one that takes a 9V (www.lowes.com)

Thanks for pointing that out. I certainly did not want to suggest that the HF moisture meter is the one to get. It is just a cheap option that works well for me. When I got it I was also disappointed to see those button cell batteries but at least then the first set was already included. However, it's now a good three years and still working on that first set. In the end, you won't use it that often; mainly in the fall to see which stacks can go in the shed.

 

[BrotherBart]

I have the HF meter. The LR44 batteries are as common as water and I buy them off of eBay for eight bucks for fifty of them. Shipping included. They go in my MM, my plug in thermostats and my wife's hearing aids as well as my digital calipers.

ETA: Just checked and HF sells 24 of them for $4.99.

 

[smokedragon]

Fair enough.......I like my 9V meter because I keep a bunch of those around for the carbon monoxide and smoke detectors anyway.