Auto burn control add on

[Rogerwood]

I recently installed a 2004 Lopi Liberty. It works great, but I would like to add an automatic burn rate control to the fresh air intake. So I don’t have to check it every hour to adjust the temperature.

My idea is to install a variable position damper in the fresh air intake ductwork and have it controlled by a thermostat connected to the stove and/or the flu.

my hope is to set the desired temperature and then have the damper stay fully open until the set temp is passed and then the damper would vary its position to maintain the set temp. Ie. Fully closed when the stove overheats to fully open when its cold.

I guess it would need to have 3 Or more temp settings to have 3 or more damper positions.
Has anyone seen something like this or know of other stove models that do this (that I could order and adapt its parts to mine)?

i have a lot more DIY ability than money. So I’d rather build my own than buy a newer model.

 

[Tron]

A damper, a stepper motor + control board on the damper's axis, a few DHT22 sensors (if you want to measure room temperature, measuring stovetop or flue temperatures should also be possible with the right thermocouples) and a small arduino plus some code should do it. That would be the DIY approach.
Be sure to program a large hysteresis, though. That control circuit is going to be laggy as hell.

 

[bholler]

I recently installed a 2004 Lopi Liberty. It works great, but I would like to add an automatic burn rate control to the fresh air intake. So I don’t have to check it every hour to adjust the temperature.

My idea is to install a variable position damper in the fresh air intake ductwork and have it controlled by a thermostat connected to the stove and/or the flu.

my hope is to set the desired temperature and then have the damper stay fully open until the set temp is passed and then the damper would vary its position to maintain the set temp. Ie. Fully closed when the stove overheats to fully open when its cold.

I guess it would need to have 3 Or more temp settings to have 3 or more damper positions.
Has anyone seen something like this or know of other stove models that do this (that I could order and adapt its parts to mine)?

i have a lot more DIY ability than money. So I’d rather build my own than buy a newer model.

Why do you feel the need to check it every hour?

 

[Tron]

It may not have a thermostat?

 

[xman23]

Some years ago there was a brother here that built what I believe was an air control. And at least one stove manufacture that had one. I envisioned building it, as I have designed PID controls. The goal would be, add any amount of wood at any time and let the control run the stove.

 

[mellow]

Wood stove automation using the Raspberry Pi

Well I am working on the raspberry pi... as a mechanical engineer programming isnt coming natural to me. C++ is ok, python is harder... Troubleshooting now.... thermocouple readings are off....think the ADS8495 is bad) BUT for about $10 I already have a decent readout...

www.hearth.com

 

[bholler]

It may not have a thermostat?

Lopis don't have thermostats but there should be no reason at all to require adjusting it hourly

 

[Highbeam]

There used to be several bimetallic coil thermostats available which could be added to a wood burner to control the intake air in response to stove temperature. The Amish like to add them to furnaces in place of electronic controls. Even Condar made one at one time.

Little box with a dial and a chain hanging out to lift the flap.

It might be crude but beats having to futz with the air control if you want to do other things AND would like the stove to be somewhat controlled.

Ideally your stove is designed with a thermostat like the BK but that is very rare.

I believe that electronic controls are coming to stoves but not yet!

 

[bholler]

Guys I burnt non thermostatically controlled stoves for years. I never adjusted the air on any of them after the first 10 or 15 mins. With good fuel and proper draft you can set it and forget it.

 

[Highbeam]

Guys I burnt non thermostatically controlled stoves for years. I never adjusted the air on any of them after the first 10 or 15 mins. With good fuel and proper draft you can set it and forget it.

I think that depends on how consistent you want your stove output to be. Forums are full of stove enthusiasts that want above average performance. If you can tolerate the natural swings in output of a normal burn cycle then a manual air control is totally adequate.

I do like the idea of an automatic high temperature control though to prevent over fire of either the flue or the stove.

Would also like an under fire control to prevent smolder and creo.

What the heck, while we’re at it we may as well get total thermostatic control and catch up with the wood furnace guys who already enjoy this,

 

[ckr74]

I built one for an Englander nc-30. It worked ok but there are certain times (circumstances) that I needed to manually control it or over ride it. It was a bi-metallic coil set up.

 

[bholler]

I think that depends on how consistent you want your stove output to be. Forums are full of stove enthusiasts that want above average performance. If you can tolerate the natural swings in output of a normal burn cycle then a manual air control is totally adequate.

I do like the idea of an automatic high temperature control though to prevent over fire of either the flue or the stove.

Would also like an under fire control to prevent smolder and creo.

What the heck, while we’re at it we may as well get total thermostatic control and catch up with the wood furnace guys who already enjoy this,

I want simple my stove to be simple durable work without power and not require much maintenance at all. That is why I burn wood. If I wanted central heat I would just push the button and save myself allot of work.

You guys really make way to much out of the heat curve thing. I did it for years and unless it was extremely cold my house would only vary a few degrees over an 8 hour burn.

 

[begreen]

Lopis don't have thermostats but there should be no reason at all to require adjusting it hourly

Agreed. I usually watch over the stove flue temp for the first 30 minutes or until the air is set very low. After that I don't touch it for another 6-8hrs and then it's just to open up the air a little bit to help burn down the coals.

 

[bholler]

Agreed. I usually watch over the stove temp for the first 30 minutes or until the air is set very low. After that I don't touch it for another 6-8hrs and then it's just to open up the air a little bit to help burn down the coals.

I usually don't have issues with coals so I usually don't touch it untill I need to reload

 

[Highbeam]

Agreed. I usually watch over the stove flue temp for the first 30 minutes or until the air is set very low. After that I don't touch it for another 6-8hrs and then it's just to open up the air a little bit to help burn down the coals.

This 30 minute thing is what I do to with my noncat in the shop now. I have learned to trust the stove and since my fuel is consistent and I have one of the controllable stoves (yes, some are more controllable) it all works out. Especially helpful has been that dang auber flue monitor. I can instantly see that my air control movements are not too aggressive on the way down to the known safe cruise setting. Then I forget about it until it needs to be reloaded. Luckily, the shop building is large and can absorb the inevitable temperature swings. Honestly, I have changed the way I use the NC30 from high output bursts to lower output and more efficient burns at normal temperatures. I give credit to the auber, better fuel from a shed, and working from home.

There are a set of users that want a more consistent output to try and maintain a tighter house temperature range. Even if that means adding cost and complexity to the stove. Running on the ragged edge of too cold or too hot can cause anxiety.

 

[bholler]

This 30 minute thing is what I do to with my noncat in the shop now. I have learned to trust the stove and since my fuel is consistent and I have one of the controllable stoves (yes, some are more controllable) it all works out. Especially helpful has been that dang auber flue monitor. I can instantly see that my air control movements are not too aggressive on the way down to the known safe cruise setting. Then I forget about it until it needs to be reloaded. Luckily, the shop building is large and can absorb the inevitable temperature swings. Honestly, I have changed the way I use the NC30 from high output bursts to lower output and more efficient burns at normal temperatures. I give credit to the auber, better fuel from a shed, and working from home.

There are a set of users that want a more consistent output to try and maintain a tighter house temperature range. Even if that means adding cost and complexity to the stove. Running on the ragged edge of too cold or too hot can cause anxiety.

Size your stove right set it up properly and learn how to use it properly and you won't be running on the ragged edge.

 

[Hoytman]

As Highbeam said, why complicate it. The Amish have already made it simple on their stoves using the bi-metallic thermostats.

As far as computer control gadgetry and wall thermostats for your wood stove...we’ve already been there and done that. It has already been in the building and left.

Quadra -fire Adventure Series I, II, III. Computer mechanism where the ash pan used to be, and a thermo on the wall. Had impressive burn times to rival BKK stoves.

At some point will they come back to stoves? Probably. If I’m not mistaken MF Fire has brought computers back to stoves.I think some of the more modern contemporary and European designs may also be utilized electronics/computers to make stoves more efficient.

 

[Highbeam]

Size your stove right set it up properly and learn how to use it properly and you won't be running on the ragged edge.

Sorry, it's not that simple. I run both of my stoves on the ragged edge. Not so much the noncat in the shop as I wrote above but I certainly could. Let's just say that you don't see a benefit to additional control of your stove in your home. This thread is for someone that does want additional control.

I can totally understand why an operator would want automatic thermostatic regulation and welcome this advancement.

 

[Highbeam]

As Highbeam said, why complicate it. The Amish have already made it simple on their stoves using the bi-metallic thermostats.

As far as computer control gadgetry and wall thermostats for your wood stove...we’ve already been there and done that. It has already been in the building and left.

Quadra -fire Adventure Series I, II, III. Computer mechanism where the ash pan used to be, and a thermo on the wall. Had impressive burn times to rival BKK stoves.

At some point will they come back to stoves? Probably. If I’m not mistaken MF Fire has brought computers back to stoves.I think some of the more modern contemporary and European designs may also be utilized electronics/computers to make stoves more efficient.

All currently approved wood furnaces use computer control of burn rate.

 

[EatenByLimestone]

Why not look at pellet stoves?

 

[Hoytman]

All currently approved wood furnaces use computer control of burn rate.

Understand. I was talking about wood stoves.

 

[bholler]

Sorry, it's not that simple. I run both of my stoves on the ragged edge. Not so much the noncat in the shop as I wrote above but I certainly could. Let's just say that you don't see a benefit to additional control of your stove in your home. This thread is for someone that does want additional control.

I can totally understand why an operator would want automatic thermostatic regulation and welcome this advancement.

Yes I understand some people want that and I see no issue with that at all for people who want it. My comments were about checking and adjusting hourly. Because honestly if that is nessecary there is something very wrong with the setup fuel or operation.

And I have run an Englander 30 it is not one of the more control able ones. It had far less control than the quad regency jotul or my dad's new pe that I have run.

 

[bholler]

As Highbeam said, why complicate it. The Amish have already made it simple on their stoves using the bi-metallic thermostats.

As far as computer control gadgetry and wall thermostats for your wood stove...we’ve already been there and done that. It has already been in the building and left.

Quadra -fire Adventure Series I, II, III. Computer mechanism where the ash pan used to be, and a thermo on the wall. Had impressive burn times to rival BKK stoves.

At some point will they come back to stoves? Probably. If I’m not mistaken MF Fire has brought computers back to stoves.I think some of the more modern contemporary and European designs may also be utilized electronics/computers to make stoves more efficient.

I work on lots of those amish made stoves I wouldn't be using them as examples.

 

[Highbeam]

I work on lots of those amish made stoves I wouldn't be using them as examples.

Apparently it is common for them to buy a commercial furnace and replace the electrical damper system with a bimetallic thermostat to open and close the intake.

Gravity ducted.

Pretty wild!

 

[ABMax24]

I'd be looking at trying to duplicate, or adapt, the Pacific Energy Extended Burn Time (EBT) to your stove. For a mechanical system that seems about the simplest. I think there is a huge amount of trial and error in getting something like that right though.

Otherwise I've thought about using a pneumatic cylinder on the air control plumbed to a sealed copper coil full of air or another gas on top of the stove. As the air heats it could push the cylinder closing the damper, as it cools down it could open the damper back up.

Personally though I'd go electronic, a thermocouple or 2, a programmable controller like a Raspberry Pi or Arduino, and a high torque servo should do it. Then all the adjustments are done within programming, instead of with hard parts or redesign in a mechanical system.