Question for the Thermostaticlly Contolled Primary Air Crowd - PE Summit, VC et. al.

[BrotherBart]

Got a question for you guys with thermostatically controlled primary air intakes. What is the pre-set temp that they try to maintain as the burn cycle progresses? I assume there is no adjustment available for the temp or if there is I missed it looking at the manuals.

 

[Gooserider]

Got a question for you guys with thermostatically controlled primary air intakes. What is the pre-set temp that they try to maintain as the burn cycle progresses? I assume there is no adjustment available for the temp or if there is I missed it looking at the manuals.

I don't have one, but as I understand it, the temperature is determined by what you set the secondary air control at. This controls how hot the stove runs, and it basically tries to maintain that level of burn for as long as it can, obviously you get the usual tradeoff between how hot you run and how long you can do it for.

Gooserider

 

[BrotherBart]

I don't have one, but as I understand it, the temperature is determined by what you set the secondary air control at. This controls how hot the stove runs, and it basically tries to maintain that level of burn for as long as it can, obviously you get the usual tradeoff between how hot you run and how long you can do it for.

Gooserider

That would be interesting. I have never seen or heard of a EPA certified stove that allowed you to adjust secondary air intake. They may be out there, I have just not run into them.

 

[elkimmeg]

Love to chat up this post but had a real interesting day and its off to bowling after 9:00 Est I may have some time and you are right about secondary air control no user intervention

 

[Gooserider]

Correction, I guess it is primary air - its the air that the user adjusts to control the overall stove temp. I'm in the habit of thinking of it as secondary given that our stove is a pre-epa model.

At any rate the important thing is that the thermostat temp is set partly in response to where you set the user controlled air flow.

Gooserider

 

[BrotherBart]

I know Goose. What I don't know is can they "set" a temp or is is fixed. That is what I am curious about. Their manuals don't say anything about setting it like a thermostat. In the response in the other thread from the guy with the Blaze King it looks like his is adjustable. I don't know about the Summit and the VCs.

 

[Willhound]

No adjustment on the Summit BB, at least not unless you want to try and take apart the EBT mechanism and start playing with the spring, or actuation arm. Certainly not something I would try, and besides, it works fine the way it is. As far as the temp, I've never really checked, but it's kinda hard to tell anyway since as the EBT kicks in and out you just sort of notice a gradual rising and falling of the flames, not really an on and off thing. The EBT is more or less on and off, but then it takes combustion a bit to catch up.
I'm sure someone out there (Tom Oyen?) knows what temp the thermostatic spring is designed to wind and unwind at on the Summit.

 

[elkimmeg]

I can describe what I do wityh both My Vermont castings stove, that have thermatically seccondary air control. The principle is the same as the Ever burn technology down draft the smoke over the hot coals then into the secondary combustion chamber. In my case that chamber has a cat combustor.
I do what all do establish a good bed of coals then load it up somethime completely other times 3 more decent splits surface top temp is above 500 better to be 600
I wait 20 minutes +- then I may add another two splits and wait again till they get established in the burn cycle. Some where aronud 600 degrees griddle top temp,
I damper it down into secondary Cat combustor mode. About 20 minutes later I will check the stove top Temp again and if it is 500 to 650 I leave the primary air setting alone usually it is set less than 1/2 probably closer to 1/4 open. One has to make adjustments due to difgferent wood and moisture content.. Same thing we all have to do. This is my final adjustment if necessary.
From that point forward, the cat combustor and the thermatic secondary supply takes over trying to mantain this temperature as long as possible. This has lasted 8 hours.

The second function of the secondary air supply, is to sypply oxygen ,to the super heated smoke, passing through the lit off combustor. It creates a super hot secondary burn in the secondary combustion chamber

The secondary air supply is located in the secondary burn chamber of cat combustion chamber
It has a temperature sensing probe a attached to a spring like mechonism. simmilar to a stove top thermometer. If the probe senses excessive heat it closes the air flap to the secondary outlet less heat it opens the flap and imputs more air to burn hoter. thus the even regulation of heat.

There are more stoves out there that thermatically control the secondary air The ETB is one The Harman Oakwood , Wood stock to mention others. I have alwasy said this function is more important t than the Cat Its the way they work together that extends burns

There is only so many BTU's wood will give up. per size fire box. The difference is how the heat is regulated and how much secondary burning of smoke can produce additional heat.

 

[BrotherBart]

No adjustment on the Summit BB, at least not unless you want to try and take apart the EBT mechanism and start playing with the spring, or actuation arm. Certainly not something I would try, and besides, it works fine the way it is. As far as the temp, I've never really checked, but it's kinda hard to tell anyway since as the EBT kicks in and out you just sort of notice a gradual rising and falling of the flames, not really an on and off thing. The EBT is more or less on and off, but then it takes combustion a bit to catch up.
I'm sure someone out there (Tom Oyen?) knows what temp the thermostatic spring is designed to wind and unwind at on the Summit.

Ah. OK that educates me some. Didn't know that it kicked in and out. Suspected it gradually opened a port as the temp went down.

Thanks Willhound.

 

[Willhound]

I was thinking the same as you BB, but if I remember correctly from the (ahem!) disscussion we had last winter regarding EBT, someone, (maybe Tom the Chimney Sweep) I think mentioned that in fact the transition from open to closed on EBT was rather quick. Not exactly either just open or shut, but I think I remember it being that the spring pushes the actuation arm, which opens or closes the damper plate. Once the arm goes so far, gravity takes over and the plate falls into place.

Tom Oyen has a good description and diagram here: http://www.chimneysweeponline.com/hoebt.htm
that makes it pretty self evident.

 

[BrotherBart]

I was thinking the same as you BB, but if I remember correctly from the (ahem!) disscussion we had last winter regarding EBT, someone, (maybe Tom the Chimney Sweep) I think mentioned that in fact the transition from open to closed on EBT was rather quick. Not exactly either just open or shut, but I think I remember it being that the spring pushes the actuation arm, which opens or closes the damper plate. Once the arm goes so far, gravity takes over and the plate falls into place.

Tom Oyen has a good description and diagram here: http://www.chimneysweeponline.com/hoebt.htm
that makes it pretty self evident.

Excellent. Thanks for the link hound. Now I know!

 

[Andre B.]

Every time I look at that drawing I get ideas

Would not be that hard to add something like it to my stove. It would be a box added over the air inlet and so would look like the after thought it is.
Getting it tuned to work well and be reliable would be the hardest part.

 

[Gunner]

So far I haven't been able to detect the exact time the EBT has opened or closed, but I haven't been looking for it either.

 

[Andre B.]

So far I haven't been able to detect the exact time the EBT has opened or closed, but I haven't been looking for it either.

The idea I have in mind would have the benefit that all the moving parts would be visible so you could see them doing their thing. But then I like old steam engines and stuff where all the moving parts can be seen.

 

[BrotherBart]

Every time I look at that drawing I get ideas

Would not be that hard to add something like it to my stove. It would be a box added over the air inlet and so would look like the after thought it is.
Getting it tuned to work well and be reliable would be the hardest part.

I hear ya. All of those stoves out there with the three inch intakes for outside air kits would be a natural for an add on controller.

Manufacturers won't do it because they have to go back through EPA certification but I sure could picture an add on being marketed by somebody.

 

[Roospike]

Busy day today so I'll be quick.

Pictured is the bottom of the PE Summit.
#1 is the main air inlet (unseen) that the main arm control open and closes over the hole.
#2 is the EBT unit and is seperate from the main air inlet.
#3 is the intake of the secondary burn chamber.
#4 is the ash pan clean out hole ( aka: "the ash hole" )

Dont know the temp as to when the EBT closes but to fine tune the thinking ... the EBT is "open" to start and as the stove get up to temp closes the EBT unit and when the stove starts to cool the EBT opens and draws more air .
I'm sure a stove with like the EBT design the main air inlet is smaller than a stove with out one and the EBT makes up the difference.