Maintaining even temperature throughout the day

[Dabbler]

Small CFM stove similar to the Englander 13. 1400 sq ft house.

I like my house on the cool side, around 61 degrees during the day and 50 at night (Yes, really). I have just switched to heating with wood during the day. I set the oil furnace thermostat at 50 degrees so I don't expect it to come on at all during the day. I do expect it to come on at night. This stove can't burn all night, but I like to get up to warm coals for an easier start in the morning so I will load it at the end of the evening.

By noon the house gets up to 70 degrees, which is too warm for me. I try to maintain a low fire so it doesn't burn out but it gets too hot for me. When it's 70 in the house it doesn't make sense to add more wood to keep the fire going.

The stove has an air inlet at the bottom. I close this down to one-half and then two-thirds as needed. The draft with my setup is "OK." Not great but I can work with it and at this time I don't want to get into changing the pipe configuration, adding to the chimney height, etc.

Question: What's the key to maintaining an even, lower temperature in the house throughout the day so I don't have to let the fire burn out and restart it later?

 

[kennyp2339]

Make small batch fires, after the night fire just do a small morning fire and call it a day

 

[begreen]

Yes, it's better to burn smaller hot fires than to let a larger fire smolder.

 

[Caw]

It's a challenge to keep a constant temperature with a non-cat wood stove just because of the technology itself. I think of it as more like a sine wave. The stove heats up, cruises, then cools off and coals. The temperature inside does the same. We keep the house largely between 68-70 but there are some dips down to 65 and as high as 72.

As you gain experience with your stove and wood supply you'll be able to fine tune each for for the given weather and your heating requirement at the time. I have access to multiple species of wood so I'll mix and match based on outside temps, if people are home, etc. It's like art.

Good luck!

 

[Dabbler]

Yes, it's better to burn smaller hot fires than to let a larger fire smolder.

My stove is so small that it basically has one size fire---small. Are you saying I should build a fire, keep reloading until it gets warm in the house, and then let it die? That would amount to quite a few fires in the course of a day.

 

[begreen]

It depends on how much heat is needed. On milder days, build a full sized fire and let it run the course until evening. Or add 2-3 splits at lunchtime if it's colder out.

 

[Dabbler]

It depends on how much heat is needed. On milder days, build a full sized fire and let it run the course until evening. Or add 2-3 splits at lunchtime if it's colder out.

That can't happen with this small stove. The longest burn I can get out of it is about two hours, and that's only after I've reloaded it several times and have a good bed of coals. Again, "full size" with this stove is very small.

 

[Garbanzo62]

If your house is too warm, crack a window. Also what are you using for wood? You don't want wet, but too dry could mean Hotter/shorter fires. Have you tested your wood with a meter? It would be interesting to know the MC of what you are burning.

 

[Caw]

So the Englander 13 has a 1.8 cu ft firebox which is almost identical to my Osburn 1600 at 1.85 cu ft. I get 6+ hour burns regularly. Are you sure your stove isn't like drastically smaller? 2 hour burn times are awful for that size stove.

I loaded it up at 11 pm last night and had plenty of coals at 7 am this morning. I'm heating 1600 SQ ft. I'm able to keep the temperature in the house between 68-70 pretty easily by varying load sizes and timing.

 

[begreen]

That can't happen with this small stove. The longest burn I can get out of it is about two hours, and that's only after I've reloaded it several times and have a good bed of coals. Again, "full size" with this stove is very small.

On a mild day that could be fine. What is the CFM make and model #?

So the Englander 13 has a 1.8 cu ft firebox which is almost identical to my Osburn 1600 at 1.85 cu ft.

Very true. Something is not making sense. Most 13NC owners report ~4-8hr burn times depending on how hard the stove is pushed for heat. That's why I want to look up the CFM stove specs.

 

[RockyMtnGriz]

I don't understand if you have coals in the morning to start the next load why you wouldn't have enough to start a load late in the day after a morning fire. It also seems odd that your backup heat would be kicking on when you're burning wood and accepting a 10 degree night time temperature drop, unless the real problem is lack of insulation in the house. Or maybe getting a ton of solar gain during the day is the issue.

Personally, I define the length of a burn as the time I can put in a new load of wood and have it start without going through a start up process, not the time that I can maintain a fire that is pumping out a lot of heat. Perhaps we're not all talking about the same thing.

Anyway, something I do when I'm really stretching to avoid too much heat during the day, yet trying to avoid another cold start, is burying the coals in ash. It seems to work best if I can just cover the coals without otherwise disturbing them. Half an inch of cover is enough. When I'm ready to go again I rake them out, give them some air for a bit, and then load normally. I can get an extra 12+ hours of time to the next reload that way, and I don't have any hardwood. YMMV, but you might try that to get you through the warm part of the day. Similarly, more ash depth in the stove results in longer coal life all by itself. I'll let a couple more inches of ash accumulate during the shoulder seasons than in the cold weather when I want that space for additional wood.

 

[Caw]

That can't happen with this small stove. The longest burn I can get out of it is about two hours, and that's only after I've reloaded it several times and have a good bed of coals. Again, "full size" with this stove is very small.

I posted in your other thread but I'll show it here too. I just reloaded my Osburn 1600. Same exact size firebox as your stove. 5 regular sized splits causally loaded only takes up half the firebox. This will burn for a few hours while I'm outside working and I'll have coals until dinner. I could easily Tetris this wood in and fit double this amount for an overnight burn. Are you sure your stove is the same as an Englander 13? What is the exact model #?

 

[Dabbler]

Are you sure your stove is the same as an Englander 13? What is the exact model #?

I don't know the model offhand. I can say with certitude that it will absolutely not burn the way you have your wood stacked.

 

[Caw]

There must be a huge draft issue then. I loaded this with a STT of 250 just about 15 minutes ago and its cruising along now at 700.

 

[begreen]

I don't know the model offhand.

Model info should be on the UL plate on the back of the stove.

I can say with certitude that it will absolutely not burn the way you have your wood stacked.

Sounds like there is an issue with draft or the wood, or both.

 

[Caw]

Just some proof of concept. This is what's left 3 hours later. It'll be reloadable on these coals for another couple hours.

 

[Dabbler]

I found the model #: 13 NC CLP, which is identical to the Englander 13 model #.

 

[begreen]

I found the model #: 13 NC CLP, which is identical to the Englander 13 model #.

Did the UL label say Englander or CFM as the mfg.?

 

[Dabbler]

Did the UL label say Englander or CFM as the mfg.?

I can't get behind the stove to read the rest of the label as it's in a tight corner. I have the original manual from Home Depot and it says CFM on it.

 

[Dabbler]

If your house is too warm, crack a window. Also what are you using for wood? You don't want wet, but too dry could mean Hotter/shorter fires. Have you tested your wood with a meter? It would be interesting to know the MC of what you are burning.

OK I'll crack a window. That will also help the draft plus some fresh air in the house would be good. Wood: oak and maple. Definitely dry. I didn't know there was such a thing as "too dry."

I didn't mean to provoke a discussion of my entire setup, which could probably use improvement. My original question was only about maintaining an even temperature throughout the day without overheating the house and having to let the fire die.

OK, here's a theory to ponder: Because the stove doesn't have great initial draft, I have to split the wood fairly small, like four inches. Then I have to build the stack with a lot of air by criss-crossing the pieces. Then I have to leave the door open an inch for the first 30 minutes. Closing the door before that will smother the fire. Opening a window helps. So my theory is that all that is resulting in burning the wood too fast, which increases the temperature in the house. However, after about one hour the fire seems to be burning pretty normally. I reload when there are bright coals and some flames left. At that point it will burn larger logs, like 5" or 6". Then I can close the air inlet 2/3. So it looks like the stove has OK draft once the fire is hot.

My theory about the poor initial draft: The hole in the wall is too low, such that the vertical pipe from the stove is only 8 1/2", followed by a 90-degree bend and a 21" horizontal pipe to the wall. I'm stuck with what the original owner/builder did decades ago. The chimney height was approved by the fire department but that doesn't mean it's ideal. Plus the house is on a hill.

 

[Dix]

On a mild day that could be fine. What is the CFM make and model #?

Very true. Something is not making sense. Most 13NC owners report ~4-8hr burn times depending on how hard the stove is pushed for heat. That's why I want to look up the CFM stove specs.

The 13 will burn for 4-6 hours, throw heat for 6 - 8. My experience.

 

[Caw]

I know it's not what your aiming to discuss but that burning methodology is showing poor draft overall not just at the beginning. 8.5" vertical immediately to a 21" horizontal is nuking your draft.

Please don't feel insulted at all I'm just trying to help and being very upfront and provide as much info as I can as we have nearly identical stoves. The difference being I have a 24" straight vertical chimney. I'm also burning 3 year old bone dry wood but you said your wood is good so let's skip that for now.

Thoughts:

Yes the beginning isn't good. If your wood is dry under no circumstances should you need to lincoln log and keep the door open for 30 minutes. That is way way way too long. This picture is 2 minutes into a cold start and I'm about to close the door for the burn:



You're also reloading way too early. This is why you're getting such short burns. There shouldn't be any flames left at all when you reload. In fact there shouldn't have been flames for a good hour or two at least. Coaling is part of the burn cycle. There should be a nice quiet coal bed and STT temps around 250-300 for most people. When you reload too soon you're just burning wood faster and sending BTUs up the flue. I suspect you're doing this because your draft is weak and if you wait until the proper time it won't take off.

This is what a reloadable situation looks like in my stove. Id break these up and take them forward then rebuild the fire:



As far as the actual burn you should be able turn the air down much further than 2/3 of the way. That's burning the wood too fast and losing heat up the flue. Most modern stoves in cold weather want to be turned down 90% or so for peak efficiency. Here's what my stove looks like turned down 90% cruising along at 700 STT with a full load:

So I disagree that is has good draft once it's hot. I think it's poor all the time and that's really hurting you. That horizontal run is draft death. If your wood is fine then the bad draft explains all your problems. Only ways around that are maybe changing to 2 x 45 degree elbows but with only 8.5" I'm not sure how you'd do that. Really the chimney needs to be changed but that's huge $.

The stove is never going to right for you and easily do what you want with this setup. It's designed to be fully loaded and have the air turned down for secondary combustion and you just don't have the draft to support that so you suffer. Short hot burns are all you can do but those are time consuming and wasteful.

I'm sorry I wish I had better advice other than spending tons of money on a new chimney. But I'm hopeful seeing what it it supposed to look like and what that stove is really capable of is remotely helpful.

 

[begreen]

I know it's not what your aiming to discuss but that burning methodology is showing poor draft overall not just at the beginning. 8.5" vertical immediately to a 21" horizontal is nuking your draft.

This was pointed out in the other related thread with the suggestion for a remedy on the stovepipe end.

Removing damper from woodstove pipe

I would like to remove the damper from the flue pipe on my woodstove. A workman replaced the pipes and installed a damper over my strong objections. The instructions that came with the stove clearly said to not install a damper and cited federal regulations for this type of stove. I'm not...

www.hearth.com

 

[Dabbler]

You're also reloading way too early. This is why you're getting such short burns. There shouldn't be any flames left at all when you reload. In fact there shouldn't have been flames for a good hour or two at least. Coaling is part of the burn cycle. There should be a nice quiet coal bed and STT temps around 250-300 for most people. When you reload too soon you're just burning wood faster and sending BTUs up the flue. I suspect you're doing this because your draft is weak and if you wait until the proper time it won't take off.

Yes, the part in bold is correct.

Thank you very much for your detailed analysis. I'm starting to understand things now. I didn't realize just how wrong my setup was because this setup is all I've ever known in this house and I just assumed it was correct.

Well, on the bright side, the stove is functional and it has saved me often during a power outage. Therefore it's useful even absent any improvements. Do you agree? It's just becoming clear now that I will be interrupting my work frequently to tend the stove. I'm only now realizing that this isn't normal. In my mind, the goal was to keep the wood burning. I think you're saying the goal is a long, slow burn, right?

Given the limitations of my setup, I'm tempted to save my two cords of wood for power outages and for spring and fall, when one fire in the morning is sufficient to bring the house temperature to a comfortable level without burning oil. From now until mid-March maybe I should make life easier (although more expensive) and just use the oil burner. If I do this, I would probably only use a half a cord per year. I hope the wood will last four years without rotting.

Conclusion: The short vertical rise means I will always have poor draft and there's not much I can do to overcome that except to burn short, hot fires, whereby a lot of heat goes up the chimney. Is that correct?

I actually do feel better armed with this knowledge. Now I know what to expect over the long term and I can decide what to do based on the reality. THANK YOU, CAW! Much appreciated.

PS I apologize for starting three different threads about my woodstove. I thought I had three different problems. I see now that there are related.

 

[begreen]

On that note, closing thread.