New to wood stoves--has a question

Hi folks.  I am sorry to put this question here but I was not sure where to go to ask.  I am brandie new and am trying to find out how to post a question about wood stoves.  Thanks!

Hi Steph!

I made your post be it's own thread. I hope that helps! Please give us some more details about your question, and we'll try to help answer it!

What kind of stove?

how cold does it get where you live, and for how long?

what kind of wood are you going to burn?

What else can we help you with?  

Fire away and let's get you warmed up.

:)

Craig Dobbson wrote:What kind of stove?

how cold does it get where you live, and for how long?

what kind of wood are you going to burn?

What else can we help you with?  

Fire away and let's get you warmed up.

:)

Thanks for the quick response, guys!  I hope I am replying in the right area.  Before I go further, can you let me know?  Thanks!!

You are doing everything right so far, Steph.

By the way Steph,  Welcome to permies.  Glad to have you with us.

OK.  It looks like I'm in the right spot!

I have a TRUE NORTH 19  19 1/2 inches wide...27 1/2 inches high.

I live in Hopkinton, Ma, about 25 miles West of Boston

Right now we are experiencing the cold snap you are, but normal temps will run somewhere between 20 and 35, my best guess, through February.

Thanks so much for opening the door for questions!  Here goes...

I have been burning with this stove for two years.  It is in the basement of a raised ranch, approx, 1300 sq. ft.  Last year I bought very wet wood (was told it was seasoned) and burning was difficult to say the least!

This year, I bought wonderfully seasoned wood and it burns like a dream, in comparison!  The wood is oak, ash, beech, birch (white and dark), maple (not sure what kind).  Right now, my main issue is that my wood is burning down very quickly.  

I have a nice bed of coals on which I lay two medium splits.  I try to mix up the type, WHEN I CAN.  I am still leaning to tell the difference between species of wood.  I then criss cross two more splits on top of those.  These are a bit smaller than than first two.  I keep the door open until the flame gets established.  Once the stove top themo. reaches 350, I close the air inlet ( a lever at the bottom of the stove) about 1/4.  When stove reaches 400, i close to 1/2-3/4.  When it reaches 450-500 I close to 1/8-1/4.  FIRST QUESTION: AM I CLOSING DOWN THE STOVE AT PROPER INCREMENTS OF TIME/TEMP?  I have tried to begin the close down process when the temp is 500+(not 350), but that seems to make the temp in the stove go down faster???  Like clock work, the stove temp will drop to 325-300 in about an hour, maybe and hour and 15 minutes leaving me with a box filled with logs that crumble to large coal chunks when I poke them.  I have been playing around with smaller loads the past day or two.  Found that more wood did not equal longer burn.  Just MORE COALS!  I have been told that maple burns a lot like what I explained.  When I learned that I started burning more oak.  That gave me a longer burn and was able to get upstairs temp to 72, some times 74 (outside temp as also 28-32) much higher than it has been the past week with single and negative digits.  Now lucky to keep house at 70.  BUT, I am pretty sure I am mixing in SOME oak.  It just boggles my mind to see such "poor" performance from my stove, even using maple, when I read that many people use maple a lot!  It's also frustrating when I read that people are getting 6-10 hour burns!!

That leads me to my next QUESTION: HOW IS BURN TIME DEFINED/MEASURED?  I do have a perfect amount of coals in the morning to restart a fire.  My average time, from final shut down to morning re-light is about 6 hours.  BUT, the house is usually at 64 or 65.  There have been mornings when it has been 68.  Maybe on less cold days.  

Some misc. information that may help...first fire up is around 6am.  Home from work 5-6 hours later.  In this cold snap, house is 62-64.  Normal temps, house 66-70 (I can live with that!)  Tested stove for leaks...all good, none.  Had chimney cleaned professionally at beginning of burn season.  Cleaned self Thanksgiving weekend...took apart indoor pipes and cleaned, ran brush down main pipe, which is free of trees etc, is about 12+ feet high, bought stove new, stairwell from basement is open to the first floor, keep about 10-14 days worth of wood stacked inside.  

Wow, I hope this is not as exhausting to read as it has been to write!!  If it's ok, I am going to recap questions to make sure I hit the main ones...too tired to go back and re-read

1) Why is my stove not able to hold a burn temp above 350 for more than an hour?  Even with a mix of wood species?

2) How is burn time defined/measured?

3) Why is my wood not burning down all the way?  Why all the coals despite good draft and dry wood.  ( i have a meter and the majority of my wood is 10% or less)

4) How do I differentiate between wood species with and without bark?  

Craig, I can't thank you enough for taking the time to read my note.  I, as we all are, am trying to save money.  But in addition, I am plain curious and now determined to master my stove and heat more efficiently

Stephanie

I went to the True North webpage  Can you tell me if it's the TN10  or TN20 that you have?  That might help me answer.  

Hi Stephanie, is THIS your stove?

If so, it's a 2 cubic foot firebox which is a decent size but not huge (my stove is 3 cubic feet).  When I load it up for the night I usually just have enough coals in the morning to get it relit (8-10 hrs later).  I pack as much wood as possible in there if it's cold (below 0F).  I don't have a thermometer so I have no idea what my stove temps are.  I had a lot of coals the past week, just when I would have preferred the extra space in the stove for more wood.  I'm still learning my stove too.  I believe that if I let it burn down longer, the coals will give up their heat and shrink to ash.  It's just hard to wait that extra few hours when you want to turn the heat up.  My house varies between 61 in the morning to 69 when the stove's been running well.  This is for outside temps in the -20 to +30F range.

A thick pile of coals in my stove tends to limit airflow around new wood so it doesn't burn as hot and forms more coals.  Elevating a log off of the coals on some smaller splits gives a hotter fire.  So last week when I had excessive coals, I would rake the coals forward as much as possible, put down two small splits and then a bigger split crosswise on top of them.  That log would really burn hard which I think gave the other coals more time to burn down while I still got some quick heat.

Now for the questions:
I burn with the air inlet mostly open if I want the fire to burn hot and heat up the house.  If I don't need as much heat, I turn it down halfway or more.  Overly simple but I guess that defines me

Burn time is a very nebulous number.  Manufacturers are very good at maximizing their stove to get as high a number as possible.  And I'm guessing their stopwatch doesn't stop until the last ember goes out.  6 hours overnight on a firebox your size seems very reasonable.

I'd let the coals sit and burn/cook/glow for another hour or two before you add more wood.  If you think there's a lot of ash mixed in that you'd like to remove, rake the coals to one side and scoop out the ash, then repeat on the other side.  Try to rake the coals forward to be nearer the air inlet.

Wood ID comes with experience.  Given the number of species you have, it will take a little while to learn.  I can ID oak, maple and birch easily but it's hard to describe.  All of those are good woods so I wouldn't really sweat it.  If you're going to buy wood for the foreseeable future, you may want to buy a couple years worth.  Then you can stack it and know it will be truly dry when you need it.  Oak seems to need three years to dry out in my climate.

Good luck and welcome to Permies!

Roberto pokachinni wrote:I went to the True North webpage  Can you tell me if it's the TN10  or TN20 that you have?  That might help me answer.  

It is a TN19

Mike Jay wrote:Hi Stephanie, is THIS your stove?

If so, it's a 2 cubic foot firebox which is a decent size but not huge (my stove is 3 cubic feet).  When I load it up for the night I usually just have enough coals in the morning to get it relit (8-10 hrs later).  I pack as much wood as possible in there if it's cold (below 0F).  I don't have a thermometer so I have no idea what my stove temps are.  I had a lot of coals the past week, just when I would have preferred the extra space in the stove for more wood.  I'm still learning my stove too.  I believe that if I let it burn down longer, the coals will give up their heat and shrink to ash.  It's just hard to wait that extra few hours when you want to turn the heat up.  My house varies between 61 in the morning to 69 when the stove's been running well.  This is for outside temps in the -20 to +30F range.

A thick pile of coals in my stove tends to limit airflow around new wood so it doesn't burn as hot and forms more coals.  Elevating a log off of the coals on some smaller splits gives a hotter fire.  So last week when I had excessive coals, I would rake the coals forward as much as possible, put down two small splits and then a bigger split crosswise on top of them.  That log would really burn hard which I think gave the other coals more time to burn down while I still got some quick heat.

Now for the questions:
I burn with the air inlet mostly open if I want the fire to burn hot and heat up the house.  If I don't need as much heat, I turn it down halfway or more.  Overly simple but I guess that defines me

Burn time is a very nebulous number.  Manufacturers are very good at maximizing their stove to get as high a number as possible.  And I'm guessing their stopwatch doesn't stop until the last ember goes out.  6 hours overnight on a firebox your size seems very reasonable.

I'd let the coals sit and burn/cook/glow for another hour or two before you add more wood.  If you think there's a lot of ash mixed in that you'd like to remove, rake the coals to one side and scoop out the ash, then repeat on the other side.  Try to rake the coals forward to be nearer the air inlet.

Wood ID comes with experience.  Given the number of species you have, it will take a little while to learn.  I can ID oak, maple and birch easily but it's hard to describe.  All of those are good woods so I wouldn't really sweat it.  If you're going to buy wood for the foreseeable future, you may want to buy a couple years worth.  Then you can stack it and know it will be truly dry when you need it.  Oak seems to need three years to dry out in my climate.

Good luck and welcome to Permies!

Mike, thanks for sharing your experience!  I have been raking coals forward and burning them.  I agree with you that it's tough to wait for them to burn down while the in home temp sits still or goes down.  But, it is helpful to know that what I am experiencing is common.  I'm glad that I found this forum!  I am looking forward to learning as much as I can!  Thank you!

How far does your chimney rise above the highest part of your roof?  It should be at least three feet above it, so that it get's good draw.  It sounds like you are not getting good airflow, and Mike gives some good advice on this.  Always put smaller wood below your larger wood to ensure both good airflow and good combustion.  All stoves are going to perform differently but you should be able to get better combustion, even when you damp it down.  Since you have an afterburner chamber, your stove is supposed to burn hot, and you have good hardwood, so that shouldn't be a problem.  I'll have to get back to this, as I am heading off to work.

Roberto pokachinni wrote:How far does your chimney rise above the highest part of your roof?  It should be at least three feet above it, so that it get's good draw.  It sounds like you are not getting good airflow, and Mike gives some good advice on this.  Always put smaller wood below your larger wood to ensure both good airflow and good combustion.  All stoves are going to perform differently but you should be able to get better combustion, even when you damp it down.  Since you have an afterburner chamber, your stove is supposed to burn hot, and you have good hardwood, so that shouldn't be a problem.  I'll have to get back to this, as I am heading off to work.

HI Roberto!  Thanks for putting time and energy into this!  The chimney is stainless steel and is at the back of the house.  I don't think it is 3 feet above the highest point of the roof.  I have a raised ranch with one single roof.  When I look at the house from the street, I can see the top of the chimney just over the top of the roof. It is definitely not 3 feet above it.  The chimney itself is at least 20 feet tall and there is nothing (trees, buildings etc.) around it.  Happy to send pictures tomorrow if that would help.  I put a load in at 7 and will check it soon to see what happens.  

A few more thoughts.  I have done the "dollar" test with my door and i was not able to pull the dollar out.  When I start a fire, I never have problems.  I usually do a top down if starting from scratch or just add wood to already existing coal bed.  Logs usually start up in 30 seconds to a minute.  When i close the door, the flames are ROARING.  They stay strong even if I damp it down to 7/8th closed.  Hope this helps!

Sorry I'm late, I had an 11 hour shift.  

I'm out of the loop on the dollar test.  But if it seems positive to you, then that's good!

It sound like you are getting adequate draw even with a 'shorter' chimney.  You have good chimney length, and I'm thinking that you likely have no bends in it if it's got a roaring start up draw, so... I'm not sure what advice to give.  You don't seem to have an issue with startup, but I'm going to go through my own way to start a fire.  

If there are any leftover charred wood I pull them all to the front and center by the air outlet.  I set up a small split piece across the fireplace about 4 (maybe 5) inches back of the door, and if there was char I put it in front of this split in the center.  This 4 inch gap allows air to be in front of this piece (as does the char because it is largely air), but also allows a couple larger splits to be set on this first piece about 5 inches apart raised up on an angle toward the front.  This allows good airflow under the larger wood, which not only allows air and flames to go under it, but it allows the wood to heat up and further dry out before it even gets engaged in the flames.  I usually use some birch bark and cedar kindling here in front of and on the small sideways split, but paper and other small split wood will work similarly to the birch bark and cedar.  I place kindling first and then kindling and small splits alternately between the two larger pieces, and then put a couple small splits and then a large split on top of the kindling stack.  I always ensure that there is plenty of air flow /channels in the kindling and small split arrangement.  My dad prefers the tee pee fire start up, and I like it too, but a cabin burns as well as a tee pee, and so I'm somewhere in the middle with my fire lay.  I light a piece of birch bark underneath some small cedar kindling and as soon as I see the cedar catch, I can close the door so that it is resting on it's latch (not fully closed).  I let it rip like a rocket for a few minutes, and then I close the door.  The air is wide open, and is kept so until I can see through the glass that the majority of the blackening on the firebricks has turned to light grey/white (usually another few minutes, but as much as ten).  At that point the damper is closed completely down (but in this stove that might be equivalent to 7/8's or 3/4's on yours, I don't know... all I know is that there is still plenty of air flow in my stove when it's completely shut down).  I let the fire do it's own thing with that configuration until all the small stuff has been reduced to a load of coals.  By this point I usually open the stove, and push the two medium splits (which have been involved in the fire on most sides at this point, and so have char and coals) toward each other, sandwiching the hot coals of the smaller wood.  There is uneven burning under these two medium splits and that creates enough air channels, but if I don't feel that that is the case, I jam another small piece under them, raking some of the coals on and around it.  At this point I can fully load the stove, and it will last for about 6 hours.  If I put a couple very large  and very knotty full rounds or large splits in there, then it might last 8 hours.  To have a fire last 8 or more hours is rare, with the new wood stoves; and that is a good thing, in a way, because it means that the stoves and the people are meant to burn hotter fires for a shorter time, rather than a longer fire that is too cool (and thus has much more potential for creosote/chimney fires).

I have no idea why you are not getting complete combustion if you are getting a ripping start up and you have dry hardwood.  I would maybe suggest experiment with layering more small wood on the bottom, with plenty of air gaps.          

Roberto pokachinni wrote:Sorry I'm late, I had an 11 hour shift.  

I'm out of the loop on the dollar test.  But if it seems positive to you, then that's good!

It sound like you are getting adequate draw even with a 'shorter' chimney.  You have good chimney length, and I'm thinking that you likely have no bends in it if it's got a roaring start up draw, so... I'm not sure what advice to give.  You don't seem to have an issue with startup, but I'm going to go through my own way to start a fire.  

If there are any leftover charred wood I pull them all to the front and center by the air outlet.  I set up a small split piece across the fireplace about 4 (maybe 5) inches back of the door, and if there was char I put it in front of this split in the center.  This 4 inch gap allows air to be in front of this piece (as does the char because it is largely air), but also allows a couple larger splits to be set on this first piece about 5 inches apart raised up on an angle toward the front.  This allows good airflow under the larger wood, which not only allows air and flames to go under it, but it allows the wood to heat up and further dry out before it even gets engaged in the flames.  I usually use some birch bark and cedar kindling here in front of and on the small sideways split, but paper and other small split wood will work similarly to the birch bark and cedar.  I place kindling first and then kindling and small splits alternately between the two larger pieces, and then put a couple small splits and then a large split on top of the kindling stack.  I always ensure that there is plenty of air flow /channels in the kindling and small split arrangement.  My dad prefers the tee pee fire start up, and I like it too, but a cabin burns as well as a tee pee, and so I'm somewhere in the middle with my fire lay.  I light a piece of birch bark underneath some small cedar kindling and as soon as I see the cedar catch, I can close the door so that it is resting on it's latch (not fully closed).  I let it rip like a rocket for a few minutes, and then I close the door.  The air is wide open, and is kept so until I can see through the glass that the majority of the blackening on the firebricks has turned to light grey/white (usually another few minutes, but as much as ten).  At that point the damper is closed completely down (but in this stove that might be equivalent to 7/8's or 3/4's on yours, I don't know... all I know is that there is still plenty of air flow in my stove when it's completely shut down).  I let the fire do it's own thing with that configuration until all the small stuff has been reduced to a load of coals.  By this point I usually open the stove, and push the two medium splits (which have been involved in the fire on most sides at this point, and so have char and coals) toward each other, sandwiching the hot coals of the smaller wood.  There is uneven burning under these two medium splits and that creates enough air channels, but if I don't feel that that is the case, I jam another small piece under them, raking some of the coals on and around it.  At this point I can fully load the stove, and it will last for about 6 hours.  If I put a couple very large  and very knotty full rounds or large splits in there, then it might last 8 hours.  To have a fire last 8 or more hours is rare, with the new wood stoves; and that is a good thing, in a way, because it means that the stoves and the people are meant to burn hotter fires for a shorter time, rather than a longer fire that is too cool (and thus has much more potential for creosote/chimney fires).

I have no idea why you are not getting complete combustion if you are getting a ripping start up and you have dry hardwood.  I would maybe suggest experiment with layering more small wood on the bottom, with plenty of air gaps.          

HI Roberto!  When you say your fire lasts abut 6 hours, what does that actually mean?  Does the temp of the fire box stay within a burn zone of 300 to 450?  Is there still flame in the box?  The house temp reaches and stays where you want it?
Bring on as much detail as you want!!!  This is one thing I have never been able to understand.  Thanks!  Would love to hear others experiences as well!!

My approaching elderly retired parents like the house to be pretty warm (around 75 to 80 F), and we don't generally let the house get colder than 70 F.  I'm often wearing T shirt or no shirt.  This is a small house, not tiny, but small (two bedroom), and pretty well insulated (six inch walls).  The windows are the main draw of temperature.  The floor is pre-heated to just under 50 F by a small electric space heater in the crawl space below the house.  We burn primarily pinus contorta (lodgepole pine), and have some birch and and spruce in the mix; birch and fir are considered our local 'hardwoods', though they are soft compared to your woods.  I don't know the temperature in the firebox. The firebox will have a bed of coals in six hours, but not lots of coals and no flames in six hours.   But the house is so small, and everything in it has absorbed that 75 to 80 degree temperature and becomes thermal mass, which slowly releases if the fire is burnt out.  My dad goes to bed after me, and I get up way before him, so it works out well. There is a stone facade around the stove that grabs some of that heat.  Our woodstove also has a fan, which we turn on sometimes in the morning to move the heat around the house a bit faster.  You might want to create some thermal mass near your stove that can help hold some of your heat?  A fan makes a big difference in getting some of your heat away from that one area.  My parents and I keep our bedroom windows open when we are sleeping, which doesn't help with holding temperature, but we like it cool in the bedrooms and we get lots of oxygen.  Not very efficient.  But we burn way less wood then most people, despite all this, because the house is small and the stove is somewhat central to Kitchen, living room, dining room, and bathroom.        

Right now the fire is pretty much out from the morning fire (which wasn't a huge fire).   The temp outside right now is 26F and the temp inside is 78 F.  I'm heading out so I'm going to get the fire going again, or remind Dad to do it when there is a break in the hockey game he's watching.  :)  

I read somewhere with energy conservation that if your household temperature gets below 62 F, you will be constantly fighting the battle with your house's (and your stuff's) thermal mass.  

I liken it to the analogy that it takes a great deal of energy to get a pot of water to boil but once it's up to that temperature, it takes a relatively small amount of energy to keep it near that temperature (you need to have your burner on high to get it up, but then you can maintain it on low).  I hope that makes sense.  

Roberto pokachinni wrote:I liken it to the analogy that it takes a great deal of energy to get a pot of water to boil but once it's up to that temperature, it takes a relatively small amount of energy to keep it near that temperature (you need to have your burner on high to get it up, but then you can maintain it on low).

One caveat to the boiling water example - Since it's crossing a phase change it takes a bundle of energy to get from 211 degrees to 212 degrees.  Something on the order of 100x the energy it takes to get from 210 to 211 degrees.  The water also has to release that same huge amount of energy to drop back below boiling.  

Another analogy for the wood stove would be accelerating your car vs maintaining speed.  Much more gas goes into getting up to speed.  I think it takes only about 10 horsepower to maintain a "standard" car at 60 mph.

Mike Jay wrote:

Roberto pokachinni wrote:I liken it to the analogy that it takes a great deal of energy to get a pot of water to boil but once it's up to that temperature, it takes a relatively small amount of energy to keep it near that temperature (you need to have your burner on high to get it up, but then you can maintain it on low).

One caveat to the boiling water example - Since it's crossing a phase change it takes a bundle of energy to get from 211 degrees to 212 degrees.  Something on the order of 100x the energy it takes to get from 210 to 211 degrees.  The water also has to release that same huge amount of energy to drop back below boiling.  

Another analogy for the wood stove would be accelerating your car vs maintaining speed.  Much more gas goes into getting up to speed.  I think it takes only about 10 horsepower to maintain a "standard" car at 60 mph.

Can't thank you guys enough for sharing your experiences!  Big help!  I spoke with a woman at a stove store near me and she seemed to think my lack of full combustion ( after only one hour, temp is down to 300 and pile of logs that crumble into chunks of coals) is due to overly dry wood.  I have been using maple with moisture levels between 3% and 7%.  She suggested that I mix in some wood with higher moisture content.  
I knew my wood was dry, but I have not heard it resulting in poor combustion.  Anyone else?  I took advantage of the warm weather today and cleaned my stove pipes and chimney.  While putting my pipes back on, i realized that the two pipes that come out of the stove and attach to an elbow that attaches to the main pipe that goes through the outside wall had a gap between them (the top pipe did not sit snug on the bottom one).  I sealed it with some gasket rope.  No more gap!  going to see if this changes my combustion problem?  Any thoughts??  Thanks, all!  

Wow, I've never heard of firewood that dry.  If you're using a moisture meter to check it, are you splitting a piece and checking the freshly split surface?  The dried out end of a piece of wood will usually read lower moisture than the inside of the piece.

I've never seen overly dry wood cause a problem but I'm not an expert...

Mike Jay wrote:Wow, I've never heard of firewood that dry.  If you're using a moisture meter to check it, are you splitting a piece and checking the freshly split surface?  The dried out end of a piece of wood will usually read lower moisture than the inside of the piece.

I've never seen overly dry wood cause a problem but I'm not an expert...

Thanks, Mike.  I brought some oak into the house today,  will mix it in tomorrow and see what we get!!

Steph Morey wrote:

Mike Jay wrote:Wow, I've never heard of firewood that dry.  If you're using a moisture meter to check it, are you splitting a piece and checking the freshly split surface?  The dried out end of a piece of wood will usually read lower moisture than the inside of the piece.

I've never seen overly dry wood cause a problem but I'm not an expert...

Thanks, Mike.  I brought some oak into the house today,  will mix it in tomorrow and see what we get!!

Alright, gang.  I woke to house at 62.  Overnight temp was 12.  Did a burn down of leftover coals.  Loaded two medium/big pieces of oak (one piece was 10%, the other was 11%) on top of two small pieces (enough to keep the splits off the coals.  Worked really well, saw much quicker ignition and clearly better air flow!)  Then two more medium pieces on top in criss  cross fashion. Total of 4 pieces of wood.  Working with idea to not over load the box.  Keep reading that that is not efficient or clean way to burn.  Agree?  Disagree?  I let stove top temp reach 400 and began shut down process.  First was about half way closed.  Second was about 5-8 minutes later and that was the final close to 1/4 open.  Stovetop temp is 500.  Not sure how long it stayed at 500.  But once it hit 400, it stayed there for about 45 minutes.  Then slowly made it's way to 300 to finish off at an approx burn time of 2 hours and 20 minutes.  At that time, there was a BIG pile of unburned wood that broke easily into big chunks.  Have begun the burn down process again.  The oak clearly provided more heat in a shorter amount of time than the maple I have been using.  i noticed a much slower burn inside the box, even at the beginning.  I think this may have to do with clearer pipes from the clean out yesterday and possibly, sealing the gap between the pipes?  Very excited about the temo increase in short time!  But, why the big pile of unburned wood/coals?  When I am here, not a huge deal as I an rake coals forward and burn down.  But, I work and am not in house for 6-7 hours at a time.  Anyway, the mystery continues and as always, thanks to all!!