The change in burn rate of a wood fire is eons by even tiny SBC standards. Take relatively infrequent sensor readings, use slow-decay exponential smoothing, and only make small infrequent adjustments. An electronic PID might be hard to tune, but a good-enough software version could probably run on a 6502.
Meh, not needed for a stove and if you’re interested the wood furnace and wood boiler guys already have this. Some even use oxygen sensors in the exhaust.
I am going to pick on you because you were the first to reply, and to extend my opinion. Right away you have stated your “Minimum Setting” is 1 o’clock, how can that be static? Unless your stove can ride the hole nonstop or you turn up the dial over your preferred room temp and the thermostat does not fully close the flapper for any length of time, then dump the excess heat out of your house( like open a window)? Not trying to sound rude just challenging the mindset I see on the forum.
You're misinterpreting the "minimum dial setting", it has nothing to do with the heating needs of your house, but is where (for some) they will stall the cat. For those who cannot "ride the hole" indefinitely, which will be most, there will some setting on your dial below which the cat will fall out of the active before the wood is mostly consumed. On some, there may even be a setting where the stove can go out completely, leaving half the load unburned in the stove. The higher of these two settings would be referred to as your minimum dial setting, in the parlance that has evolved on this forum.
Its only static to my particular setup, I know anything before 1 O'clock will cause the cat to stall, for my particular application, the stove is in the basement, the heat either conducts through the non insulated wood floors to the upstairs, or goes through the convection loop of the top of the basement stairs and down to the stove, for this reason.. on warmer days here 1 o'clock on the t stat will keep an active cat, but the room wont press the stove so hard to shed heat and force the t-stat to open more and call for additional air to boost the fire box.
That doesn’t make any sense at all !!
You beat me to my next point: how many people have tried the lowest setting in such conditions? I have because I get major solar gain and sometimes when it is actually sunny my house does not need any extra heat.
This is not correct. The flapper has a mechanical connection to the knob you turn. A bimetallic coil moves it around slightly from this set point, but you can always drive it hard shut, way beyond the operating range of the bimetallic coil. Put otherwise, the thermostat makes small adjustments, but the knob can make large adjustments.
Actually, the stove thermostat responds to stove temperature, not house temperature. It’s function is to regulate stove temperature and it works well.
Yes you are right in riding the hole but not in context of a minimum dial setting for preventing stall in my opinion. To me it seems that bimetallic coil has a lot of movement. If you turn your dial to wide open on a cold stove that flapper is open all the way to the the screw stop that prevents over centring, when that stove get ripping hot that flapper is almost totally closed.
Would you want to clarify or correct this statement?
No, this is not the case. The flapper does not, nor does it ever need to, completely close when the knob is set at max. If this were even possible, people would be complaining about their stoves going "black box" when set on high.
Just want to start with I am challenging an idea and not anyone. I think of it as debate, so in no way do want to make any one angry but more us collectively to think out of the preconceived box.
I have a princess and the thermostat is middle back behind and below the stove pipe. It is getting heat from the stove and also cooled from incoming air. On the princess it is very evident that it is designed for as little heat to be emitted to the back to allow the close install tolerances we get. So in my opinion the thermostat sees a balance of stove and room. Your whole house is a heat sink for your stove and the stove temp reflects the demand from the house. You are changing constants though, adjusting the dial for a constant house temp. I am using the constant of minimum setting to prevent cat stall.
I agree the knob has much more rotation to keep the flapper from not opening but most of that is dead adjustment or just riding the hole until you get flapper engagement. Also I did not say it will close the flapper on high but will get close when the stove is cooking hot. It is hard to tell how much travel is actually in that bimetallic coil because we all have a very similar starting point for a cold stove (Room temperature). There is a very stern warning in the manual to not use the stoves in a unheated building as the chance for the thermostat to prevent over fire is high. I do understand what you are saying so I will challenge you to my opinion. Remember we are talking about minimum dial setting to prevent cat stall. Get your stove running on your known minimum and let cruise for a bit to stabilize. Next safety pop up some kind of portable walls around your stove to box it in and see what happens. If the heat can’t be easily transferred to your house the thermostat will keep your flapper closed more or if fully closed much longer and unless you can permanently ride the hole, it will stall. There can be many more variables that can be used in this test(minimum dial setting): anything that affects draft, any variation in fuel, etc.
