Part 4 of Mega-Query: Flue Liners, Burn Time and “HeadRoom”

[TruePatriot]

Part 4 of Mega-Query: Flue Liners, Burn Time and “HeadRoom”

Hi all!

This is Part 4 of my “Mega-Query—Which Woodstove to Get?” series of questions on this wonderful forum. This section discusses Flue Liners, Burn Time and “HeadRoom”.

Please see this link for the specifications of the house, etc…, should you need to clarify something to answer the following question: https://www.hearth.com/talk/threads/6812/ Thanks.

Which Type of Flue Liner—Corrugated or Smooth?

I put this question before my woodstove-specific questions, because I’ve read enough responses here to know that the first thing the experts are going to need to know is what type of flue/chimney are we talking about. To save you from going back to the previous post this time, I’ll just reiterate that though the house was built in the 1890’s, my guestimate is that th fireplace chimney, which we plan to cut into, is on an outside wall, and was probably built in the 1960’s or 1970’s.

The chimney is a two-flue design, of brick construction, and the fireplace flue is tile-lined. The chimney is two stories tall and also houses a separate flue for the gas boiler. There are two, small, cast iron “clean outs” in the basement, under the chimney.

We plan on having a qualified professional cut into the chimney, through the sheetrock above the mantelpiece, and install a to-code thimble, and line the flue with a stainless steel liner, as I’ll explain below.

Also, one of the installers I’m considering hiring swears by the Copperfield Ultra-Pro System of liners, which is apparently a flexible, corrugated stainless steel liner that is both lighter and the most expensive of all such liners.

Any thoughts on this brand of liner? Suggested alternatives?

My question is: with a straight, “modern” chimney, why not use a smooth-walled liner—wouldn’t this hold less creosote than a corrugated model? My last name may not be Daniel Bernoulli, but wouldn’t a smooth-bore liner make for a stronger, faster draft, too?

The installer says he will surround the liner with Vermiculite, for insulative purposes. Is there a better insulator than Vermiculite, for this application?

And how does one get the Vermiculite evenly distributed around the liner? Even hanging the liner from the top while pouring the Vermiculite would seem to allow for it to lay against one side of the flue or the other, pinching out most of the Vermiculite and making a “cold spot.” What am I missing here?


Maximum Burn Time
As I said, I think my first priority (okay, after Maximum Heat Output) is Maximum Burn Time, and I don’t just mean how many hours can it keep coals sufficient to relight without kindling, though that is part of it.

Re: Maximum Burn Time I’m also concerned with the highest heat output over the longest time and I’m kind of assuming the Pacific Energy Summit “Classic” should beat all the rest of these stoves in this dept., because of its thermostatically-controlled, EBT technology.



How Important is “Headroom”?
I’m using the term “headroom” to describe the actual space through which wood can be passed, into the firebox. The term also encompasses the actual room once the wood is inside the firebox, without hitting secondary burn tubes or other obstructions. This dimension is, of course, far smaller than the external door height and, in many cases, is smaller than the external opening in the stove body’s skin, due to internal baffles, flanges and/or glass guards, depending upon the model.

Why do I care about headroom?
Because I believe headroom is one of the critical factors controlling how long a burn one can have, as it limits how many large rounds (or quarter rounds, depending on tree size) one can insert for the night. I don’t want to make a bunch of skinny splits when I split, (slow splitter, lazy operator, 36” diameter rounds) so I want to put the largest pieces in at night that I possibly can, and still have a good secondary burn, and efficient combustion overall.

Headroom is also not a measurement listed in ANY of the stove mfr.’s literature, to my knowledge. Nor is it something one can rely on to be measured by a dealer. My girlfriend asked a stove salesperson to measure the headroom on one stove, and he told her “10 inches!”. When I measured the stove later, however, it was 8 and 1/4” between the flanges, inside the door opening. (And I thought sleazy, uninformed salesmen only worked in auto dealers….)

I will list what I have for headroom figures, and where they came from, and would love it if owners of these models could supply the actual measurements, where I am off:

Country Canyon ST310—8 ¾” measured by a dealer who I trust.

Lopi Liberty—9” to 9 ¼” Estimated by factory rep., over the phone

Quadra-fire 5700—11”, measured by me, if I remember correctly.

Napolean 1900—8 ¼ ”, measured by a dealer who I trust.

P.E. Summit “Classic”--7 ½”, Estimated by factory rep., over the phone.

Thanks everyone! See you in the next section?

Peter

 

[Larry H]

Just from my chimney cleaning experiences at my Folk's lake house, Dad has two liners in two flues - one stove in living room (smooth Simpson Duravent Class A) and one flexible corrugated with insulating sleeve around it (I don't remember the brand) to the stove in basement, and the smooth one is always cleaner and easier to clean. Yes, they are two different brands of stoves and the basement stove has different dynamics that apply to it, but it doesn't clean as easily being corrugated compared to the smooth in my opinion.

 

[elkimmeg]

Copperfield Ultra-Pro System of liners

I have the copperfields book here their is no such liner called copperfields anything Is he talking home saver?



Maximum Burn Time
to get the maxium burn time one must have the largest fire box. Lets not confuse the 3.0 wimpy size of a Pe sumit to a blaze super king 4.5 cu ft fire box. You want maxium burn times and effeciency
then why not get it. It's called blaze king. Not 63 % Epa minium effeciency but 72%. You want log size Blaze king wins that hands down. You what longevity capacity and clean burning none of you choices are listed above the Epa Minium 63%. Don't bleieve me Go to the EPA site and review it for yourself? Then review the Blaze kings

 

[jtp10181]

We sell a corrigated 25' stainless liner from BDM (Balsim something something) for under $500. It comes with the flashing and cap also. In another post I saw someone being quoted almost $3000 for a SS liner, which is insane!

 

[RonB]

Copperfield Ultra-Pro System of liners

I have the copperfields book here their is no such liner called copperfields anything Is he talking home saver?



Maximum Burn Time
to get the maxium burn time one must have the largest fire box. Lets not confuse the 3.0 wimpy size of a Pe sumit to a blaze super king 4.5 cu ft fire box. You want maxium burn times and effeciency
then why not get it. It's called blaze king. Not 63 % Epa minium effeciency but 72%. You want log size Blaze king wins that hands down. You what longevity capacity and clean burning none of you choices are listed above the Epa Minium 63%. Don't bleieve me Go to the EPA site and review it for yourself? Then review the Blaze kings

The Quad 5700 is a non-catalytic stove with up to 76% efficiency.

 

[elkimmeg]

I just checked the Epa listings here is the direct cut and paste for the 5700i

(broken link removed to http://www.epa.gov/compliance//monitoring/programs/caa/whcert.html)
Grams % tested heat range Certification renewal date

5700i Noncatalytic 4.2 63 % 11800-45900 4/24/2007

 

[Roospike]

I guess i am a little confused by "head room" but here are the # for you.

Summit:

Door opening total heigh 9" tall X 18 3/4" wide.
Inside firebox from brick on the bottom to the secondary burn chamber is 12 1/2"

 

[MountainStoveGuy]

I just checked the Epa listings here is the direct cut and paste for the 5700i

(broken link removed to http://www.epa.gov/compliance//monitoring/programs/caa/whcert.html)
Grams % tested heat range Certification renewal date

5700i Noncatalytic 4.2 63 % 11800-45900 4/24/2007

elk, thats the standard rating for all non cat stoves with a epa tag hanging in them. The other rating is what the manufacture states it will achieve.

 

[Roospike]

FYI" The big blaze King with the big 4.6 cf firebox is not 82% efficient fully loaded at a 40 hour burn time ! Thats all BS and a numbers game. The 82% efficiency is around 6-7 hour burn time and over that is goes way down hill. Also the heat you get off of a full load of wood in the blaze king over 40 hour burn time is less then a small electric space heater.

Big #'s game and a lot of BS .

 

[RonB]

I just checked the Epa listings here is the direct cut and paste for the 5700i

(broken link removed to http://www.epa.gov/compliance//monitoring/programs/caa/whcert.html)
Grams % tested heat range Certification renewal date

5700i Noncatalytic 4.2 63 % 11800-45900 4/24/2007

elk, thats the standard rating for all non cat stoves with a epa tag hanging in them. The other rating is what the manufacture states it will achieve.

Elk, the model you're quoting (5700i) is a fireplace insert not a free standing stove.
The "i" at the end of the number signifies insert. Furthermore, they don't list it in the current Quad brouchere. Must be an older model.

 

[Roospike]

I guess i am a little confused by "head room" but here are the # for you.

Summit:

Door opening total height 9" tall X 18 3/4" wide.
Inside firebox from brick on the bottom to the secondary burn chamber is 12 1/2"

BTW: If your looking to put larger then say a 9" X 18" ( 9" x 12" or whatever size) split in your stove then you need to plan on seasoning your wood splits and rounds for at least 3-4 years before burning.

 

[TruePatriot]

WaterBoss:

Re:

Just from my chimney cleaning experiences at my Folk’s lake house, Dad has two liners in two flues - one stove in living room (smooth Simpson Duravent Class A) and one flexible corrugated with insulating sleeve around it (I don’t remember the brand) to the stove in basement, and the smooth one is always cleaner and easier to clean. Yes, they are two different brands of stoves and the basement stove has different dynamics that apply to it, but it doesn’t clean as easily being corrugated compared to the smooth in my opinion.

Thank you for your input which I feel kind of confirms what I feel is the obvious, i.e., that a corrugated liner would hold more creosote. I understand they were in different installations, but still, it only makes sense. I got the feeling these installers just never like to work with the straight flue pieces because if there's any angle to the chimney, they must have to switch to corrugated?

Does anyone know if it's common to use straight flue liners, generally? Does everyone pretty much use corrugated? Which would you prefer (and why?) if you had a straight chimney?

Re: insulating materials: Vermiculite or a wrapped, "fabric" insulator? It seems to me it would be hard to ensure (especially with a flexible liner) that the liner wasn't lying against one side of the flue when the Vermiculite was poured, thereby reducing the R-factor where the liner was touching the flue (we have an outside chimney).

Does anyone have an idea of the cost differences between corrugated stainless liners and rigid (straight) stainless liners? Recommendations?

Then I got thinking that if the flue is filled with Vermiculite, there'll be zero visual inspection possible, in later years, between the liner and flue.

So...Vermiculite or a wrapped "blanket" as the preferred insulator?

I have been told that with top and bottom block-off plates, even though the tile-lined, brick chimney is on an outside wall, that if I use a flue liner, I won't even need to insulate it. Thoughts? I imagine it would be expensive to add it later....
.

Elk:

Re: this:

Copperfield Ultra-Pro System of liners

I have the copperfields book here their is no such liner called copperfields anything Is he talking home saver?

You know...one of the dlr/installers I talked to did mention "home saver"...but I don't remember which one. So it's either my mistake or the dlrs.--sorry 'bout that, and thanks for calling it to my attention. I'll clear it up when I talk to them again.

Re: your Blaze King recommendation--that is one impressive stove! I do appreciate your making me aware of it, and I actually discussed that in my "Mega...#8: Emissions" post, a few days ago. It looks like a great stove, but I want to watch the secondary burn, so that rules out a cat stove. And their awesome performance does come at a bit of a price premium, you know? I called a dealer and the round numbers I got were approx. $3,000. list, but about $3-400. off, right now. But thanks again--it's a tank! (Loved the dual fans and thermostatic control, btw....)
>

jtp:

Re:

We sell a corrigated 25’ stainless liner from BDM (Balsim something something) for under $500. It comes with the flashing and cap also. In another post I saw someone being quoted almost $3000 for a SS liner, which is insane!

I appreciate knowing the price of any of this dlr-controlled stuff (caps, liners, etc....). I can't get seem to get even a ballpark answer of costs on this stuff that doesn't begin with "Well, I'd hafta see your installation first...." To do what--give me the per-foot LIST PRICE of the liner? Why is that a big secret? I should have asked him if the per foot liner-price changes, depending upon whether it's looked up in the office or the field, I guess. So thanks again for your cost-example--it helps.

Speaking of "insane" prices--if 25' of liner includes the flashing and cap, for under $500.--does $100. for the cap alone, seem excessive? (I did get one dealerto offer that piece of pricing info, actually.)

Thanks.

 

[TruePatriot]

Roo,

Re:

I guess i am a little confused by “head room” but here are the # for you.

Summit:
Door opening total heigh 9” tall X 18 3/4” wide.
Inside firebox from brick on the bottom to the secondary burn chamber is 12 1/2”

Thank you.

I do concede that the following definition is unclear in that "headroom," (my own, made-up word), actually involves two separate measurements, i.e., the opening through which wood can be passed, and the height inside the firebox in which wood could be stacked. I can see that might be confusing, in that the opening can only pass a split that is "x" inches tall, whereas, once inside, smaller splits could be stacked on top of that first piece, to a height possibly greater than "x" (where "x" is the opening thru which would can be passed). So, I'm sorry, that is a little confusing, but you did correctly understand what I originally wrote:

How Important is “Headroom”?
I’m using the term “headroom” to describe the actual space through which wood can be passed, into the firebox. The term also encompasses the actual room once the wood is inside the firebox, without hitting secondary burn tubes or other obstructions. This dimension is, of course, far smaller than the external door height and, in many cases, is smaller than the external opening in the stove body’s skin, due to internal baffles, flanges and/or glass guards, depending upon the model.

Why do I care about headroom?
Because I believe headroom is one of the critical factors controlling how long a burn one can have, as it limits how many large rounds (or quarter rounds, depending on tree size) one can insert for the night. I don’t want to make a bunch of skinny splits when I split, (slow splitter, lazy operator, 36” diameter rounds) so I want to put the largest pieces in at night that I possibly can, and still have a good secondary burn, and efficient combustion overall.

Headroom is also not a measurement listed in ANY of the stove mfr.’s literature, to my knowledge. Nor is it something one can rely on to be measured by a dealer. My girlfriend asked a stove salesperson to measure the headroom on one stove, and he told her “10 inches!”. When I measured the stove later, however, it was 8 and 1/4” between the flanges, inside the door opening. (And I thought sleazy, uninformed salesmen only worked in auto dealers….)

So Roo...I appreciate your taking those measurements for me. But I have a question--and don't take offense: the factory rep. I had on the phone wasn't sure...they "estimated" (from what, I don't know) that only a 7.5" or 8" round would fit into the stove. So my question is:

Are there any flanges, or other obstructions inside the door opening that reduce this 9" dimension, or could you actually pass a 9" diameter round into your stove, no problem? For example, whatever the "total height of the door opening" is on this Harman Exception, check out these "mini-andirons" that are in the way--they'd limit passing big rounds into the firebox a little bit, wouldn't they? LOL (broken link removed to http://www.harmanstoves.com/callouts.asp?id=9) And I've found less obvious impediments inside the door openings of other stoves, like flanges and such, that also reduce the size of the round that can actually be loaded.

And how hot do you suppose those Harman's andirons (glass guards) would be, after a good burn? Are they andirons...or branding irons?

In terms of getting wood into that Harman, I thought "liftover" was a term we only used in the autobiz--I didn't think I'd need it to describe a woodstove. And you thought my "headroom" term was confusing! ;-)

But your P.E.'s 9" is very good, among the four stoves I'm considering, in that the Country Canyon ST310 has an 8 and 3/4", and the Napolean 1900 has only 8 and 1/4". The Quad 5700 has allegedly 11" but I didn't write it down when I measured it--the dlr. (over the phone) says it'll take an 11" round.

And re: this:

BTW: If your looking to put larger then say a 9” X 18” ( 9” x 12” or whatever size) split in your stove then you need to plan on seasoning your wood splits and rounds for at least 3-4 years before burning.

I appreciate knowing this. Of course, given the pace of my glacially-slow research, I think half my wood might be there already! ;-) Thanks again.
>

 

[Gunner]

Are there any flanges, or other obstructions inside the door opening that reduce this 9” dimension, or could you actually pass a 9” diameter round into your stove, no problem?

I posted this before when talking burn times....yes you can pass a 9"er threw the door...this one went in a few months ago.

 

[TruePatriot]

Well, that answers that--the ruler don't lie!

Definitely scores a point for the P.E.--that's the second biggest pass-thru in the bunch of stoves I'm looking at.

Thanks, Gunner.

 

[zzr7ky]

Hi -

Yes I used 6" rigid stainless liner. I used Simpson snap around insulation in 24" lengths. It drafts like crazy even in warmish weather and it's 17' tall. House is built tight. Go rigid if you can. I could as I went straight up though the top of a metal Heat-a-lator type firebox, avoiding the whloe damper smoke shelf issue.

The corrigationas also result in laminar flow; slow moving gas at outer diameter cools more, allows cooler pipe, results in more creosote deposits. Insulation also helps this. I'd be more concerned with this if you're looking for long burns.

It really needs very little cleaning.

ATB,
Mike P

 

[jjbaer]

[quote author="TruePatriot" date="1174238684

Speaking of "insane" prices--if 25' of liner includes the flashing and cap, for under $500.--does $100. for the cap alone, seem excessive? (I did get one dealerto offer that piece of pricing info, actually.)

Thanks.
[/quote]

Depends on what you get for the $100....mine costs that much but it's worth it...it's a 1-piece cap that lies on top of the top flue tile and wraps around the edges of the tile. I put high temp sealant on the top of the flue tile and attached it. It also has 4 screws that bite the side of the tile to hold it on even tighter. The cap is hinged and has a locking pin on the side. You release the locking pin and the top half of the cap pivots 90 degrees to expose the liner all without removing the top plate that remains screwed to the flue tile. In 5 seconds I can open the hinged top cap and look straight down the liner for inspection and cleaning. Go here to see it (by the way, this company sells very low cost, high-quality stuff...25 ft of 1/2" insulation is about $250.

http://www.chimneylinerinc.com/

click on "chimney rain caps and dampers" on the left hand side of this site and part way down the new link you'll see the hinged cap.

ex: 25 ft of 6" 316 TI, 0.006" thick flex stainless steel, top assembly (basic top kit...pay a few $ more for hinged cap), stove connector is about $429. Add in about $250 for the 1/2" insulation and $50 more for premium hinged top cap and you get it all for about $730. They have free shipping, it's all made in America and has a lifetime warranty. Also, the 1/2" insulation when coupled with the liner, I believe gives it the UL 2100 deg F rating against fires not to mention peace of mind......

I know I sound like a salesperson but I'm not and don't work for them. I researched all sites very thoroughly and this site had all the best components and prices and I bought mine from them. I love that hinged top cap.

 

[TruePatriot]

Mike:

Hey--thanks for sharing. Re:

Hi -

Yes I used 6” rigid stainless liner. I used Simpson snap around insulation in 24” lengths. It drafts like crazy even in warmish weather and it’s 17’ tall. House is built tight. Go rigid if you can. I could as I went straight up though the top of a metal Heat-a-lator type firebox, avoiding the whloe damper smoke shelf issue.

The corrigationas also result in laminar flow; slow moving gas at outer diameter cools more, allows cooler pipe, results in more creosote deposits. Insulation also helps this. I’d be more concerned with this if you’re looking for long burns.

It really needs very little cleaning.

ATB,
Mike P

Everything you said about the corrugations makes sense to me, including your comment on long burn-times. Glad to hear about the strong draft--it would seem to indicate that you do not have much (any?) leakage between the sections--thanks.
>


castiron:
Re:
------------------------------------

[quote author="TruePatriot" date="1174238684

Speaking of “insane” prices--if 25’ of liner includes the flashing and cap, for under $500.--does $100. for the cap alone, seem excessive? (I did get one dealerto offer that piece of pricing info, actually.)

Thanks.

Depends on what you get for the $100....mine costs that much but it’s worth it...it’s a 1-piece cap that lies on top of the top flue tile and wraps around the edges of the tile. I put high temp sealant on the top of the flue tile and attached it. It also has 4 screws that bite the side of the tile to hold it on even tighter. The cap is hinged and has a locking pin on the side. You release the locking pin and the top half of the cap pivots 90 degrees to expose the liner all without removing the top plate that remains screwed to the flue tile. In 5 seconds I can open the hinged top cap and look straight down the liner for inspection and cleaning. Go here to see it (by the way, this company sells very low cost, high-quality stuff...25 ft of 1/2” insulation is about $250.

http://www.chimneylinerinc.com/

click on “chimney rain caps and dampers” on the left hand side of this site and part way down the new link you’ll see the hinged cap.

ex: 25 ft of 6” 316 TI, 0.006” thick flex stainless steel, top assembly (basic top kit...pay a few $ more for hinged cap), stove connector is about $429. Add in about $250 for the 1/2” insulation and $50 more for premium hinged top cap and you get it all for about $730. They have free shipping, it’s all made in America and has a lifetime warranty. Also, the 1/2” insulation when coupled with the liner, I believe gives it the UL 2100 deg F rating against fires not to mention peace of mind......

I know I sound like a salesperson but I’m not and don’t work for them. I researched all sites very thoroughly and this site had all the best components and prices and I bought mine from them. I love that hinged top cap.

-------------------------------------------

Thanks for the link--that looks like good stuff! As some here have noted, I like to do research, ;-) so I can respect and appreciate your efforts in that regard. (Below, I voice a question about the .006" wall-thickness of the liner, but please don't be offended--I admit I am ignorant of what is normal in such a product.)

I think the hinged cap is a GREAT IDEA! Personally, my chimney is too high for me to want to go up there, as the roof is too steep to walk it, but if I do get up there via ladder, I'd definitely appreciate not having to use a mirror, or a lot of tools, to do an inspection/cleaning. I want one!

Mike, castiron, and anyone with experience with rigid, smooth-bore liners:

I know it's gonna seem contradictory, (as I've said I favor noncorrugated liners) but I've just thought of what may be a drawback to a rigid liner, and I'd like your (experienced) opinions.

How long are the individual sections of hard liner, and how do they couple together? Do they seem real secure?

The reason I'm asking [/b] is, it just occurred to me that, even though it would seem a smooth-walled liner flows faster and collects less creosote, if one did have a chimney fire anyway, that the flexible, ONE PIECE corrugated liner would be more secure.

In other words, I've heard stories about flue pipes "banging and flailing about" in a chimney fire, due to the sheer violence of the flames. Under those conditions, with the pipe becoming super-heated and expanding beyond it's anticipated temps., it would seem to me that, in theory, a multi-piece liner would be more apt to come apart at the seams, under such abuse, than would a one-piece, flexible liner.

Are there any known examples of this? Am I once again worried over nothing? Perhaps inspectors like Elk have seen/heard of this problem, if it even exists?

I know, I know, if the smooth-walled, rigid, multipiece liner developes less creosote, it's less likely to catch fire--especially if it's burned properly and cleaned regularly. I'm just saying, if it did catch fire, which one would you want to have--the flexible one-piece or the rigid multipiece?

Does anyone know the relative thicknesses of the two? I saw the .006" thickness listed by castiron, for the flexible, corrugated liner, above, and that struck me as t-h-i-n, but I have no frame of reference, other than the points on an old B&S lawnmower engine are set at .018", which is roughly equivalent to a matchbook cover. So the liners are only 1/3 the thickness of a matchbook cover? :grrr:

Thanks, all.

 

[jjbaer]

none taken....you'll find that 0.006" flex is pretty much standard and there's even 0.005 out there but avoid it...I did see 0.01" but that was 304 or 306 SS and the 316Ti is better against corrosion for woodburning. Also, if you have ANY bends in a long, small chimney, watch out as the rigid stuff won't easily go down it and at the damper area you'll have to probably use a flex connector length anyway to get from the stove collar to the rigid pipe (most likely the rigid won't easily pass through this damper area where the chimney turns a bit to line up with the stove collar).... Also, with the rigid (especially on a long run) you have to support it at multiple places but the flex stuff is held by a SS clamp attached to the top flue cap and between this and the stove connection, it's easily supported.

Even using flex tubing, I had to cut away part of the cast iron damper area (PITA to do this) and struggle a bit to turn the flex tube through this area.

 

[Roospike]

Yeppers, 9" round will fit with no obstructions , brackets or flanges in the way.

Posted pic shows large rounds and large splits loaded for picture porpoises only and size example. note ample extra room when filled.