Older Intrepid II

[Gooserider]

Definitely insulate that liner, it's required and will make a big difference.

I have been told its only required for masonary only chimney and not those already lined with terra cotta. All the stove shops around here say dont bother with the insulation, I would assume if local code dictated otherwise they would let me know.

Yes and no... Remember that Code is only concerned with "safety issues" - it does not really care about performance... From a safety standpoint, the insulation is only required from the standpoint of reducing the potential for damage from a possible chimney fire in a chimney that wasn't otherwise "safe" - a terra cotta tile lined chimney in good condition is presumed to be "safe" in terms of Code, so the insulation is not legally required. The building inspector wants to make sure you don't burn your house down, but he doesn't give a darn about whether or not it keeps you warm.

However the experience we've learned from the many users on the board here and elsewhere, is that external chimneys tend to have performance problems with modern stoves UNLESS they are insulated... An external chimney is a cold chimney, which will tend to draft poorly, especially when starting the stove, and require you to burn more wood in order to keep the chimney warm enough to draft properly. Open fireplaces, and the older "smoke dragon" stoves sent enough heat up the chimney that they could compensate for the poor performance of an exterior chimney, but because modern stoves are more efficient, they are also more sensitive to poor draft.

The local stove shops often seem to be catering more to the interests of the "casual burner" and don't want to scare away a potential sale by pushing the extra cost of insulating a liner, plus it can be a hassle when the customer has a smaller bore chimney than yours, so they try to minimize the need for it. However we have seen multiple cases where adding insulation has resulted in major improvements in the performance of the stove. - Thus we tend to say "required" because we are interested in performance almost as much as we are in safety.

Gooserider

 

[nediver]

does the fact that I am only going to burn at night time to supplement my heating bill make me a serious or casual burner?

How much of a pain would it be next year to pull the liner and insulate then?

My concerns are that I am new to wood stove and I am on a budget...I may find I do not even like burning wood, I do not want to lose wood, but in the short run this might be the only way for me to go...no liner for now I mean.

 

[Gooserider]

does the fact that I am only going to burn at night time to supplement my heating bill make me a serious or casual burner?

First off, no offense is meant by either term, it just can be helpful to classify how one is using the stove. I run our stove 24/7 which makes me a very serious level burner. My GF's parents build a half dozen or so fires a year in their fireplace, which is at the other extreme end of "casual burner". - I would put you in the intermediate to serious stage - you want to put a dent in your heating bill, but not burn 24/7 (though it is easy to do this if you have enough wood and a stove with a long burn time. All else aside, I find it easier to feed the stove an extra time in order to keep it going than it is to start it from scratch...)

Probably the biggest difference is that when you burn for heat, you generally want the greatest heating efficiency you can get out of the appliance, and don't want to let any extra BTU's escape out the chimney, while a casual burner doesn't really care, and is more likely to worry about how the setup looks, burning or not.

How much of a pain would it be next year to pull the liner and insulate then?

Depends - you have a big flue, so unless you have a tricky damper area to get through, or bends and such, it shouldn't be to bad. However liners are really not designed for this, the intent is that once they are in, they are there to stay... With a big bore flue you might be able to get away with it, but we generally advise against doing this as you have a fair chance of damaging the liner when you pull it out. Plus it will probably cost as much or more labor to pull the liner insulate and re-install as it did for the initial install. However there would be no real reason I can see why you couldn't do a "pour in" type insulation install later.

My concerns are that I am new to wood stove and I am on a budget...I may find I do not even like burning wood, I do not want to lose wood, but in the short run this might be the only way for me to go...no liner for now I mean.

A big bore outside flue like yours would be a nightmare to get good draft on without a liner, I definitely would not reccomend that, plus if your inspector is doing his job, you wouldn't be able to get a sign-off w/o a liner. (Your current chimney would grossly violate the cross-section area limit in Code) You might be able to get acceptable (if not great) performance w/o insulation however, so it might be worth trying that, knowing that it would cost you more to add the insulation later.

Gooserider

 

[nediver]

Ok so I got the liner installed and I decided to go with the insulation based on everyones advice. I ended up just stuffing extra insulation around the liner at the bottom instead of modifying the block off plate.

I am a little disappointed in the stove though. It really doesnt seem to throw much heat. I mean even in the small room its in there isnt that much heat. I replaced all the gaskets and the CAT, and the stove is in great condition. I get a good bed of coals going with an open damper, then load it up, get those logs burning good with the door open a bit, then close the damper down and slow the air flow. I can get a good burn like 4-6 hrs but like I said its not super hot. Is this just because its a penut sized stove? Everyone told me not to go too big because I might roast myself out of the room, but this doesnt seem right!!

 

[Gooserider]

Ok so I got the liner installed and I decided to go with the insulation based on everyones advice. I ended up just stuffing extra insulation around the liner at the bottom instead of modifying the block off plate.

I am a little disappointed in the stove though. It really doesnt seem to throw much heat. I mean even in the small room its in there isnt that much heat. I replaced all the gaskets and the CAT, and the stove is in great condition. I get a good bed of coals going with an open damper, then load it up, get those logs burning good with the door open a bit, then close the damper down and slow the air flow. I can get a good burn like 4-6 hrs but like I said its not super hot. Is this just because its a penut sized stove? Everyone told me not to go too big because I might roast myself out of the room, but this doesnt seem right!!

Well, I know that we told you several times to fix the blockoff plate to seal tightly around the liner - stuffing insulation around the bottom of the flue is NOT an acceptable substitute as it does not block the flow of heated air. We say these things for a reason.... :coolsmile:

The other issues are that it is a small stove and won't put out as much heat as a large one, and if the space isn't well insulated, you will not feel like you are getting a bunch of heat even if the stove is working well. If the cold is coming in as fast as the stove is heating the area, you won't feel like the stove is doing much.

It does sound like you are operating the stove properly - what sort of temperatures are you getting on the griddle top?

Gooserider

 

[nediver]

I would be glad to fix the block off, I have pop rivets and an extra piece of galvanized steel. How would this have a better R factor than the insulation that is copiosly stuffed in the flue?

 

[elmoleaf]

If your top blockoff plate at the chimney top is sealed tight, and you have insulation at the flue bottom, an additional metal plate probably won't make much difference except to give an added measure of safety.

I suspect if you're getting 6 hour burns and seemingly low heat, you're operating with damper closed in the 400-500F range with the primary air lever halfway over to the right? If you want to feel more heat, try operating in the 550-650 range, with the primary air full open to about 1/4 to the right. You'll have shorter burns but more heat.

For comparison, I'm heating a 1400sf 1965 ranch with average wall insulation/windows & extra attic insulation. The stove is at one end of the house, which is open floor plan (kitchen, dining, living rooms), and a fan blows heat down to the other end (three bedrooms/bathroom). With the temperature outside at about 15F, I run the stove at 600-650F to maintain about 70-72F at the house's midpoint. My experience so far has been that unless it's in the 30s or above outside, I can never operate the stove so hot as to be "roasted out of the room".

When it doesn't feel warm with the stove running, I make sure to keep water on the stove to keep the air humidity higher. Also, closing the drapes across my large picture window reduces the convective air flows (cold drafts) felt near the window, which also helps the comfort level.

 

[Gooserider]

I would be glad to fix the block off, I have pop rivets and an extra piece of galvanized steel. How would this have a better R factor than the insulation that is copiosly stuffed in the flue?

It's not so much a question of R-value as it is one of draft stopping... Insulation does not do a good job of blocking air flow, it only stops heat transfer in still air conditions (when it's sealed in a wall, for instance) You are likely to be getting significant amounts of hot air escaping up the chimney through the insulation. Adding the steel sheet to block the airflow should give a significant improvement.

Gooserider

 

[nediver]

If your top blockoff plate at the chimney top is sealed tight, and you have insulation at the flue bottom, an additional metal plate probably won't make much difference except to give an added measure of safety.

I suspect if you're getting 6 hour burns and seemingly low heat, you're operating with damper closed in the 400-500F range with the primary air lever halfway over to the right? If you want to feel more heat, try operating in the 550-650 range, with the primary air full open to about 1/4 to the right. You'll have shorter burns but more heat.

For comparison, I'm heating a 1400sf 1965 ranch with average wall insulation/windows & extra attic insulation. The stove is at one end of the house, which is open floor plan (kitchen, dining, living rooms), and a fan blows heat down to the other end (three bedrooms/bathroom). With the temperature outside at about 15F, I run the stove at 600-650F to maintain about 70-72F at the house's midpoint. My experience so far has been that unless it's in the 30s or above outside, I can never operate the stove so hot as to be "roasted out of the room".

When it doesn't feel warm with the stove running, I make sure to keep water on the stove to keep the air humidity higher. Also, closing the drapes across my large picture window reduces the convective air flows (cold drafts) felt near the window, which also helps the comfort level.

The stove typically is around 350-450 with about 350-400 being average. I cannot seem to get the stove up to 650. I was told by a sweep that it is possible I have too good of a draft, but he doubted it with only a 22 ft chimney. What do you all think?

 

[elmoleaf]

400 simply isn't hot enough to throw much heat with the Intrepid's small firebox. Also, at that low temp, the cat isn't going to burn off smoke.
If you had too good a draft, you should be burning hotter & faster, so I don't think that's the problem.

Assuming your wood is seasoned & not wet, you should be able to get 600-650F easily. Start the stove & keep the primary air all the way to the left. Let the stove get up to 450-550 with the damper open...feed plenty of small kindling if necessary. Before closing the damper, make sure that the temp is in the 500F range AND that you have a layer of hot coals in the firebox (in addition to the wood you keep feeding in). Then, top off the wood in the firebox & close the damper...move the primary air lever 1/4 to the right at most (halfway to the right will probably keep you in the 500F range).
You should typically hear a faint low rumble when the cat kicks in, and you'll see stovetop temp probably pickup another 50-100 degrees depending upon how much you reduced the primary air.

You might also check that your secondary air combustion flap is working properly.

 

[nediver]

Elmoleaf-

Thanks for the help. I will try that tonight and let you know. As for the wood, its 2 years seasoned and its mostly red oak and maple. Its very good wood, this was the reason I started the idea to heat with wood, was my access to good hardwood.

 

[nediver]

k