Can a stove pipe be too long?

I'd think burner near an exterior wall and go out lowered end of roof. More heat stays in building. Most I've seen exit the exterior wall 6-8 ft high. Go out wall, then 90 up to roof line. Insulated outside chimney will help draft and keep creosote down.

My wood stove is in the basement. Chimney exits roof at peak plus 3 foot. Easily 20 foot of block chimney, 24 foot of vertical travel from stove. Stove has 6" single wall connected to 8+ inch square block chimney. First 2 years I had a damper in the 6" single wall. When I replaced the single wall I never put the damper back in. I just use the bottom draft damper and blower intake damper to control fire temp.

When it was -18F outside there was quite a draft pulling up the chimney. On cold foggy nights I could use a bit more natural draft trying to start a fire.

 

You’re reacting to my response to this:
“Now, there are some who will contradict this but you can control your rate of burn by simply shutting the draft down on the doors.”

I was agreeing with you controlling the burn rate with stove controls. I was saying only an ignorant person (devoid of any experience with a stove) wouldn’t know that.

I never said you couldn’t control your Fisher through stove controls. Obviously you and I know what those controls are for. I was saying only a person ignorant of using a stove at all would not realize what the controls on the door was for.

Most people who know the history of stoves and fireplaces knows full well that the first control was the amount of fuel used. They also know second control that came later … the first physical means of control was a damper above the fire…just as you said.

Pot belly’s were not the first designs as you know. Many of their “crude” controls were crude because they were well worn out (as were door hinges and door mating surfaces) long before you and I were born. There were plenty of examples of leaky stoves and just as many higher quality stoves just as air tight long before the Fisher. Plenty are still repaired to be just as air tight, or better, as when new. People on coalpail refurbish them all the time as one example.

No one argued that you couldn’t snuff a fire in your Fisher. I agree…that’s the biggest fault of most modern wood stoves, imo. Thank your epa for that. However, I wasn’t even referring to that type of control.

I was saying Fisher salesman were ignorant for telling you and other people in 1976 that a pipe damper was mot needed. Salesman today, as well as chimney sweeps and anyone else…they’re all ignorant for telling people pipe dampers aren’t needed or are dangerous, and/or cause creosote. That’s BS! Not knowing how to use the damper properly or when is the biggest contributor to creosote. (I’ve seen Blaze King stove users not even use a damper…and still with a modern catalyst stove seen pictures of their completely clogged with glazed creosote chimney pipes. That’s not a stove or catalyst caused problem, it’s a person that doesn’t need to own a stove problem because they’re too lazy to follow operating directions about drying and storing wood properly problem.)

The argument isn’t about controlling the stove with stove controls…which has been done since controls were first introduced “on” the stoves themselves. It’s not about controlling the fire with only the pipe damper either.

The argument was already mentioned by me if you care to take the time and read carefully what I posted earlier. In brief, a pipe damper gives you additional control in conjunction with the stove controls. It gives additional control, safety, heat savings, and fuel savings … key words … during the time of year when the damper is best used. The damper is misused if it’s used all the time. That goes back to this…it’s still partly true that for the most part in any stove the pipe damper isn’t needed…until it is needed.

For when and how…read the quote I posted for you to read.

 

As an example:
Old cook ranges, and even modern cook ranges mostly have smaller fire boxes. (Some modern wood ranges have huge fireboxes today, but the sale still applies because these are generally heating larger homes today as well, and so the pipe damper is still necessary.)

With the smaller fireboxes of older cook ranges far less heat is wasted up the chimney and greater control over the amount of heat coming out of the stove and into the room, oven and cook top is the result of using a pipe damper “in conjunction with opening stove air controls”. The result is a hotter room if wanted, a hotter oven and cook top without an unnecessary spike in pipe and chimney temperatures. The damper is also beneficial in high winds…again in conjunction with stove controls as well.

I can’t see having “more” or “additional” control as a bad thing. In fact, the control is more finite. What’s not to like about having literally more “precise” control?

No one isn’t saying stove controls aren’t sufficient. They can be. Just look at the HECO wood/coal cook range at how many control levers there are on that stove alone. There’s even a bi-metal regulator and several other air intake dampers, internal dampers, etc. Many still employ the use of a pipe damper with them. It isn’t necessary, but it’s not a detriment either if used properly at the proper time…it’s just another “additional” control and safety.

 

My woodstove install manual states the minimum flue diameter and height. It does not state a maximum. I believe it does have a minimum pressure differential listed. I'll have to check again.

 

In that article he’s saying that stove pipe dampers were used more on “traditionally older less efficient stoves”, to which I’m certain the writer also meant any and ALL pre-epa stoves. That would include all Fishers and any other pre-epa wood stove.

Also note that he specifically mentions using a pipe damper to “reduce” the flow of air from the fire box. The problem lies with the fact he fails (just like everyone else) to include information; what the damper is capable of.

With a Fisher (any stove) set to cruise what’s the probability of closing the pipe damper and seeing stove and pipe temperatures increase?

 

This conversation is very interesting to me as I've just begun using my pipe damper due to learning I have an overdraft in my system. I understand trying to avoid its use except for when the outside temperature dictates it due to the excessive cooling of flue gas that may occur from slowing the flow of said flue gas.

However my question about this has to do with an overdrafting chimney. Is it a substantial risk to continually use the damper to bring the draft within spec even when the outside temps are warmer? By using my damper I'm able to build smaller but hotter fires on days these type of fires are warranted. Am I exposing my chimney to increased risk by doing so as long as the draft is within spec? Won't the risk be negated since I'm essentially turning my system in to one that is "normal"?

Ultimately time will tell at my post season cleaning but I would like all of your opinions on this. I've been reading as much info on pipe dampers as I can find and even climbed onto the roof the other day just to have a look and all was well but I haven't been using the damper as consistently as I now am for very long.

 

Some guys are longwinded and can type up a storm. I can't, so my voice can get lost on forums. I've used a damper for quite a few years. Using it to keep the stove temps within the right range is never wrong. Sitting at -5C/24F and my damper is engaged about 1/4 way. I shoot for stack temp 400F or above. 400 with the damper wide open on a warm day or 400 full damper on a cold day, same difference. The pipe doesn't know any better. People think a damper magically forms creosote but it's not true. Used incorrectly well sure. I actually have less build up in the pipe these days compared to before.

I can't speak for anyone else, but since I started running a damper (and blocked some secondary holes), my stove runs hotter, stays hotter longer, lower stack temps in general, and only seems to smoke a bit more initially. If your stove burns within the right parameters, it will be fine. It doesn't matter what the epa thinks.

 

That's kinda the conclusion I'm coming to as well. I'm kicking around the idea of getting an Auber digital probe thermometer to install at the very top of my chimney. With the 16' wire I could hook the unit up inside and run it to the top of my stack to the probe and monitor temps coming out of the top. No reason other than I'm kind of a data geek and think it could be fun.

That's probably a bit overkill though

 

1 reason for me to install a damper would be high winds at times which will literally suck the heat out up the flue, . 1 reason against is i would no longer be able to clean flue from the bottom up. with a roof that is extremely steep it is almost impossible to get up there to top down clean with out incurring the expense of a bucket lift of some sort. roughly a 30 ft flue from main floor to stack top. so now days i just shut the only control all the way and then block a portion on the secondary intake off as well. there still 2 more small intakes for the air wash besides.

 

So what do you do when you need more heat?

 

New Hampshire and a real winter will solve that dilemma

 

No, not necessary, Dave, as I don’t doubt you.

That explains why you don’t use a damper. Your stove is large enough that you don’t have to and you don’t mind allowing a lot of heat escape up the chimney. I bet you rarely need to clean your chimney. Nothing wrong with that.

In fact, I’d say it’s too big for anything but short fires in the shoulder season. That’s quite alright too, but some people don’t have that luxury. Some people want a more comfortable heat as well instead of 95*F of hell in their living room. Some have smaller stoves.

Your style of burning with such a large stove capable of making your house that hot is a totally different conversation as someone (indeed many) with smaller stoves needing to extract all the heat they can out of it during certain times of the year. It’s much easier to tell people they don’t need a damper under those circumstances. I’m in the same boat you are having big enough stove I don’t need a damper (but I have one in place).

(Yet another conversation…I will agree 100% nothing throws heat like pre-EPA stoves.)

Nothing wrong with the way you and others like to run, balls to the wall. Many people like that blaring heat.

For those that think they have cold weather cornered to only their part of the world.