Definitive Pacific Energy EBT test . . .

[Ivy Frank]

I had posted on an earlier thread that my EBT was closed at a stove top temp of 450, and that I was surprised by that.

So I decided to run a test.

If you have a Summit or Alderlea T-6 with an ash tray, you can remove the ash tray to visualize the EBT. What you will see is a large hole about 2" in diameter that is covered or uncovered with the 1 lever control rod. Obviously, that hole allows air to enter the burn chamber through the front of the unit.

The control lever doesn't do anything else other than cover that hole about 90% when in the fully closed position, or not at all in the wide-open position.

If you look next to that hole, you will see a metal box about the size of a thin paperback novel. About .75x5x8 inches. It is screwed to the bottom of the burn box with 4 screws. This is the EBT box.

In the EBT box you'll notice a hole about 1 or 1.25 inches in diameter. If the EBT is "off", there will be a metal plate resting on the hole, blocking it entirely except for a very small "bleed hole" in the metal blocking plate that is maybe 1/16" in diameter.

If you watch that plate and the EBT hole that it covers, you'll be able to see when your EBT opens and closes.

CONCLUSION - EBT hole is uncovered only at very high temps.

Experiment . . .

All temperatures in Fahrenheit.

A T-6 stove operating at a temperature of about 450 degrees on the center of the stove top, under the trivets is used.

Ash is cleared out using a manual shovel, and the remaining hot coals are spread on the bottom to a depth of about 1".

On top of the coals, 36 pound of well-seasoned Quercus rubrum is added in splits averaging about 5 pounds each in a front to back orientation. The wood is observed to ignite rapidly and prior to closing of the door.

The T-6 is set with the lever all the way to the left, which is high.

The EBT hole is observed to be covered.

The Primary air hole is, of course, completely open, as the lever is in the wide open position.

The unit is allowed to burn on full bore for the next 1.5 hours.

A magnetic thermometer is added to the bottom of the burn box, immediately next to the EBT unit (not ON the EBT unit).

The ash drawer is kept removed during the entire experiment.

The stove top temperature is observed to rise to about 750, stay there for about 20 minutes, and then gradually come back down.

The under stove temperature is observed to begin at 200, rise to about 550, and then gradually come back down.

Results:

The EBT flap is observed to open up only as the understove temperature rose above 450 and approached 500. At 500, the EBT flap was slightly ajar, with a gap of about 1/16" between the blocking plate and the hole in the EBT. At the understove temperature high of about 550, the cover plate in the EBT was observed to be open about 1/8 of an inch to 3/16 of an inch.

The opening in the EBT hole corresponded exactly to the understove temp, with the amount of the gap corresponding exactly with the temperature reading on the understove thermometer.

The EBT hole became blocked completely as the understove temperature fell below about 450.

I will allow the stove to cool to an understove temperature of 150 and post results later.


Analysis:
The EBT, in fact, functions exactly as I always believed it to function and exactly as the patent describes it to function; above a certain temp, the EBT opens to allow more air in, and below a certain temperature, the EBT chokes off that extra air to extend the burn by reducing the amount of available oxygen.

Unexpectedly, however, the critical temperature of the EBT is extremely high - approaching 500 degrees understove temp. What this means is that, unless you get your stove to well over 700 stove top, or get it close to 700 and keep it at that temp for some time, your EBT will not be open, given that the temp observed understove was about 200 degrees cooler than the stove top at the hottest moment of burn and did not exceed 550 throughout the burn.

My conclusion is that the EBT is only a factor at very high stove temps - during those really hot burns, the EBT opens up and allows extra combustion air to enter the burn chamber. As the fire settles down, however, the EBT closes, making the Summit and T-6, equivalent to a normal stove at extended burning temperatures.

I conclude that the EBT may function to increase combustion at high temps, but likely does very little to extend burns overnight, as the EBT is already closed at very high temps, and, accordingly cannot function to choke off air supply at low, overnight temps.



I specifically request another Summit owner or T-6 owner to duplicate these findings.

Please be sure to do the following:

Remove your ash drawer and leave it out.
Remove all ash or almost all ash and start with a layer of hot coals about an inch deep on the bottom of your unit.
Fill the unit with good hard wood.
Note that the EBT hole is covered. If you have the T-6, you can see it without a flashlight and without a mirror.
Fire it up until the stove top temp exceeds 700, preferably 750.
Keep it there for at least 20 minutes to a half hour.
After the stove has been over 700 for at least 20 minutes, check the EBT - observe that the flap above the hole is now moved up, creating a gap.

Report back.

Final note - use Hearth Gloves if you put a thermometer under the burn box next to the EBT - it's a nice quick burn if you touch anything down there with the stove fired up.

 

[karri0n]

The device doesn't seem to make much sense. If the stove is at ultra high temp, why would you want more air? It would make sense to me that the device would allow more air in as the temp cools, and close it off at higher temps. Maybe it should be called a stove runner-awayer unit?

 

[snowtime]

Your results are consistent with my observations namely EBT adding air at high temps. I do wonder if taking off the ash drawer keeps the underside and EBT cooler as there will be lots of air movement down there now. Is it possible the EBT will open at a somewhat lower temp with the ash drawer in place? This also makes the argument to keep the ashes at a lower level than most would. I mean we probably clean when we need to but it would be better to keep the ashes low with a daily clean than a heavy clean once and a while.

 

[begreen]

Interesting. That would explain why with 650 stove top temps, no EBT action on the T6. And it confirms that when the stove starts to get really hot, it gets really hot. (And seems to chew through wood too quickly.)

This is not the functionality described on Tom's EBT article. 750 temps are harder to achieve with west coast soft wood. It would be great to get a comparative test with a Summit to see if the high temperature EBT behavior is peculiar to the Alderlea T6's greater mass or not.

 

[BrotherBart]

And makes those posts in prior years of "I char, close it all the way down and let the EBT take over" even funnier. Seems the stove does fine without EBT doing anything.

I asked for two years what temp it took for folks to see the fire indicating EBT action and now I know why nobody responded. :roll: A shame really. It is a good concept and really needed on all stoves. If it had a dial on it.

 

[Diabel]

This is very interesting & informative (thanks Frank). I have been following most of the PE posts since I see one of these T6s in my house in the future :coolsmile:

How does this ebt compare to the thermostat on VC cat stoves? I believe that the VC thermostat works does the exactly opposite.

 

[begreen]

And makes those posts in prior years of "I char, close it all the way down and let the EBT take over" even funnier. Seems the stove does fine without EBT doing anything.

I asked for two years what temp it took for folks to see the fire indicating EBT action and now I know why nobody responded. :roll: A shame really. It is a good concept and really needed on all stoves. If it had a dial on it.

Exactly BB. I want some control on this sucker and may mod it to achieve that if PE doesn't step up to the plate. But first we need more data. Summit and T6 owners please report in what you see with your stove.

PS: A very big thanks to Frank for dropping in on this subject. This is what makes Hearth.com so great, peanut gallery and all.

 

[MovingOffGrid]

Having narrowed my purchase decision down to 3 stoves (PE Summit, Regency F3100 and BK Princess) and on the verge of opening my wallet for a PE summit on the merritts of it's SS baffle over Regency's Vermiculite baffle, even though I hate the dainty bendable little Summit ash ledge at the front of the stove, I am now going back to research mode again.

Very interested to hear how this turns out. With 30 feet of straight up warm chimney in centre of the home, last thing I want is a runaway locomotive stove with too little control.

 

[madison]

Stove was loaded at 7 am and then primary completely closed at 7:45.

Short day at work, home at 2. Read franks nice observations and get motivated to duplicate his test.

Science and attempts at humor now begin:

EBT closed prior to and after cleaning.

I cleaned the August 2008 vintage T6 of ash, leaving about ~ 20" square of one inch deep coals in the back center of stove with a new "KoalKeeper" shovel (be careful of the paint fumes on first use! - made in china - painted with most likely some sort of toxic black paint which immediately vaporizes on first use - this shovel should not be painted hopefully Koalkeeper reads this note and makes change).

Primary wide open, stovetop as measured on steel top with a condar magnetic is 250 degrees F. EBT Closed. EBT flap probed with Index Distal Phalanx and opens and closes.

Barometric pressure 29.88 mmHg and falling. Room temp 67F, humidity low - 24%. ~ 35 ft of class a, interior chimney system, 3 fit of adjustble DVL off stove, 2 interior 90 degree bends. And two 30's in the attic. Outdoor temp is balmy 31.8.

Fuel load is smaller load, not weighed, 5 pieces of mixed hard wood including Acer saccharinum, and Prunus serotina (just for frank and science); moisture content unknown, not completely seasoned, but does not weep moisture or sizzle. Two north-south straddling small coal pile, 3 east west on top of the two NS.

Fuel ignites in ~ 1 min, Primary open fully. EBT closed. Stovetop 250.

Chiseled some ice off the driveway for 1/2 hr, and transported wood from covered stacks into garage. No direct observations of stove. except no smoke from the chimney while outside.

40 minutes after loading stove, stove top temp reaches 700 F. Firebox thoroughly combusting. Primary 100 % open, EBT Completely closed. Reprobed EBT flap with Index Distal Phalanx.

5 mins later, racing past 750 F, primary still opened, my dilithium crystals where about to melt, so I completely closed the primary air control in one move, not my usual stepped fashion, but this load had ignited. EBT remains completely closed.

15 mins after closing primary, stovetop down to 700, Medial aspect of the EBT flap valve has now lifted two mm. Primary still completely closed. Good light show, and creaking popping stove.

Livephish (http://radio.nugs.net:8002) now playing loudly during the secondary light show and scientific observations.

30 mins after closing primary, EBT has about the 2 mm gap. Stovetop now 650F.

45 mins after closing primary, EBT has a slightly larger gap, ~3.4 mm. Stovetop has dropped to 525. Primary still completely closed. Secondary's about over.

Fuel crumples into chunks. Light show is over. Bummer, but observations continue....

60 mins later, Primary air control remains completely closed. EBT maybe slightly more open, still ~ 3-4 mm. Stovetop 450F.

90 mins, primary closed, EBT still 3-4 mm open. The fast burning Acer saccharinum is reduced to coals.

Primary opened at 105 min to see what happens to EBT, stovetop down to 350.

120 min, primary still open, EBT still open 3-4 mm.

Primary reclosed at 120 min.

140 min, primary still closed. EBT now is now closing and gap is reduced back to one mm. Stove remains at 350. Coals look like they need stirred.

////////////////////////////////////////////////////////

Except for not observing the EBT flap during the 40 min ignition of the fuel load, I think the operation of the EBT flap during this short burn cycle with a small load during the period of time with the primary closed is as depicted at: (broken link removed to http://www.chimneysweeponline.com/hoebt.htm)

Time to grill a buffalo burger. Outdoors, not on the t6.

 

[Ivy Frank]

they need stirred.

////////////////////////////////////////////////////////

Except for not observing the EBT flap during the 40 min ignition of the fuel load, I think the operation of the EBT flap during this short burn cycle with a small load during the period of time with the primary closed is as depicted at: (broken link removed to http://www.chimneysweeponline.com/hoebt.htm)

Time to grill a buffalo burger. Outdoors, not on the t6.

They "need stirred"?? Are you from Western PA? That's the only place I have ever heard the "to be stirred" changed to "need stirred."

Your testing pretty much duplicated mine. EBT closed until stove up to high temp, EBT opens when bottom of stove is heated sufficiently. EBT closes when stove cools down. You seem to have had a greater lag in time between the top and bottom of the stove - may be ash depth or time to coaling - the red oak I burned was not even starting to coal when the top hit 750.


I'll write this as diplomatically as I can - don't expect too much - I am, after all, Frank Ivy . . .

The link you posted links to a description of the EBT that is completely ass backwards and wrong, that has been completely ass backwards and wrong since we had the first conversation in 05/06, and that is in clear contrast to my results and yours.

At that link, the following folderol is presented:

"It does this by delivering a burst of combustion air to the fire only as needed to maintain secondary lightoff temperature when the draft control is turned down far enough to create the longest possible burn."

Completely and irrevocably incorrect. The EBT operates completely independently of the primary air (draft control). If you look under your T-6, you'll see that the primary air control is simply a flat piece of metal bolted on to the bottom of the firebox with a single bolt. Take the bolt out, the primary air lever is removed completely and the primary air hole is wide open. The EBT is a box next to the primary air, but it operates exclusively on the temperature of the stove, and not on the position of the primary air lever, which is irrelevant.

A bimetallic coil is attached to an actuator arm that pivots the plate so that when the firebox begins to cool below a certain point, the coil contracts, and the entire assembly hinges open to uncover the intake hole and provide extra air to the fire.

Completely ass backwards, as both of our experiments have now shown. When the fire is hot, the hole is uncovered. When the unit cools, the hole is covered.

Not only is the falsity of the quote clear based on the two experiments that have now been run, it's also completely wrong because it's the exact opposite of what the patent says and it's also common sense that you cannot extend a burn by introducing more air.


I actually think the Chimney Sweep's site is extremely well done and useful, and he seems like a hell of a guy.

I'm still, however, waiting for him to admit I am right. Back then I had a Summit insert, so I couldn't check the EBT. Now, I can.

That I'm correct about this is easily verifiable - crank the unit up to 750/800 and put the primary on full low setting. What you'll see is that the EBT will behave in exactly the same way that it did with the primary full open.

Come on Summit and T-6 people, shut off the -----ing TV and run a load up to 750 and verify the two results.

As for the person who is rethinking his decision based on draft - DONT. The T6 and the Summit are fabulous at running on a stick or two of wood or running on a full load on low, your choice. I've kept fires petering along at one stick at a time all day on a 50 degree fall day no problem. I currently have about a 33' stack, straight up, and keeping the fire at the right level is cake. Go with the Summit - I personally guarantee that you'll love it (See my review about the T-6 elsewhere).

To the person who commented that the tray being out might affect the temp around the EBT - Excellent point, very critical thinking, and I considered that.

Certainly having the drawer out will lower the temp in the EBT, because the air trapped in the ash pan no longer acts as an insulator . . . but only, I think, a bit. Why? Because the air is drawn in from the back of the unit and has to run over the EBT to get to the primary air hole anyway, so there is a constant breeze running over the EBT during normal operation.

In sum, Madison's test corroborates mine, and, while I always thought the EBT was great idea to extend burns, it now seems to me that it's a bit gimmicky and probably really doesn't do much.

I may, at some point next fall, run a complete battery of tests to check performance.

It will be easy. Ready? Simply put a temporary plate (with bleed hole) over the EBT hole from the bottom and see how much the performance of the stove changes. I'm predicting not much.

That written, the Summit is the best stove out there, IMO, and no reader of this post should consider this to be a repudiation of the unit or a critique of the stove - it is a great stove, easy to operate, clean burning, clean glass, and flexible w/regard to BTU output.

 

[jpl1nh]

I think the EBT is off calibration because you guys keep burning Latin wood and it's an American made product.

 

[jpl1nh]

Having narrowed my purchase decision down to 3 stoves (PE Summit, Regency F3100 and BK Princess) and on the verge of opening my wallet for a PE summit on the merritts of it's SS baffle over Regency's Vermiculite baffle, even though I hate the dainty bendable little Summit ash ledge at the front of the stove, I am now going back to research mode again.

Very interested to hear how this turns out. With 30 feet of straight up warm chimney in centre of the home, last thing I want is a runaway locomotive stove with too little control.

They say beauty is only skin deep. While the Princess may not be the fairest of them all, at her heart you'll find she's a true lady, with the heat giving sultry, long, steady purr of a hardworking cat. You do have to learn to operate a bypass lever though. Some people take days to get the hang of up to engage, down to disengage. :cheese:

 

[madison]

Frank, very good, i spent 5 yrs in pittsburgh, i spent some time in the mid 70's eating at the original Primantes after drinking with some North Side friends... Excellent time for pittsburgh sports. Though I drink soda, not pop (western PA humor). Apologies for the digression.

Anyway, I think are observations are similar now that I reread yours. I may disagree on a small point,

on tom's page, one of the goals of EBT is stated ..."An Ideal burn cycle should heat the fuelwood to gasification temperature (Stage 1), ignite the volatile gases in the secondary burn chamber, maximize the burn time of the secondary fire until the gases are consumed (Stage 2), then maximize the duration and heat productivity during charcoaling (Stage 3)."

In which I agree that the design of EBT does what it is designed to do,,, allows more air into the primary plenum during the hottest point of the burn no matter what position of the primary. does this make the secondary flames hotter, possibly if the primary is closed, but maybe we cannot see this with stovetop temp. Nonetheless, I agree that this may well be insignificant. Reclosing the EBT while the primary is still closed would decrease air to the firebox, prolonging charcoaling - especially in the rear corners...

Otherwise I pretty much agree with ya frank, mostly a gimmick, but i'll leave mine on the stove, and wouldn't bother replacing it if it fails.

GO STEELERS!

 

[MovingOffGrid]

well that's a nice Summit testimonial - I'm still torn on the Princess, but I want more heat in the masonry chimney, so that has me deciding to go non-cat.

Without wishing to hijack this thread, for someone buying a Summit pedestal, would it be wise to get the ash drawer? I'm guessing it may be easier to fiddle with the EBT if any ... ahem ...modifications, are ever needed. I hear most don't think much of the small ash cleanout, but it might be nice to have anyway.

 

[Hogwildz]

I may, at some point next fall, run a complete battery of tests to check performance.

It will be easy. Ready? Simply put a temporary plate (with bleed hole) over the EBT hole from the bottom and see how much the performance of the stove changes. I'm predicting not much.

That written, the Summit is the best stove out there, IMO, and no reader of this post should consider this to be a repudiation of the unit or a critique of the stove - it is a great stove, easy to operate, clean burning, clean glass, and flexible w/regard to BTU output.

[/quote]
Excellent light shed on the EBT subject Frank. As much as I hate to admit I fell for the smoke & mirrors, It appears I did.
But I still love my Summit, I get long, hot fires regardless if the EBT is functioning as intended or not.

I read the patent also, and it nearly made my head spin & I almost fell asleep.
One thing that did get my attention is this paragraph:
"Large wood stoves which are generally called "large box" wood stoves have acquired a reputation of not performing well at either high or low burn rates. One of the reasons for this is that a large stove is required to perform in a much bigger window of burn rate than the common small or mid-size units that operate in a smaller range. Existing wood stoves provide a combustion air system which is generally two or three separate air supplies, some of which may have set openings. Thus, the chosen ratio for set openings may be ideal for a particular burn, for example, a high burn, but it provides an air mixture that is only barely adequate for a low burn. Thus, the narrow window of optimum performance for a large wood stove often yields a stove that has difficulty passing emission standards and in some cases is unresponsive or uncontrollable for in-house use."

If i am interpreting correctly, which is not guaranteed, I get the idea the EBT set up is to correct a problem that older or some newer large stoves had due to having to constantly making air adjustments with several different controls to obtain a standard or more optimal burn through the entire load to coal burning process. And the second part I get in mind is that the EBT does this adjustment, although it appears yes ass backwards, but maybe not? It adds air to keep the emissions withing EPA standards? I dunno, thats kind of what I got from that particular paragraph.

Frank, on your future test, I have a thought or question. I am curious to see your results and wonder, if you cover the EBT hole, do you think A). It will create more emissions due to lack of air from the functioning EBT? And more curiously for me, do you think it may possibly extend burn times due to extra air not being dumped in during the hot cycles? I mean yes it seams a no brainer, but I wonder if it would be a considerably noticeable difference?

I have the Summit insert, and really don't want to be pulling the front lowers off to try and see the EBT.
I still would not give up the Summit. Its built like a tank, and takes the heat, and puts it out.

 

[Ivy Frank]

JP - Close. Latin wood, but PE is a Canadian product.

Moving Off Grid -

I know Cat lovers will protest, but do yourself a favor and avoid a cat. It's just extra parts, extra fuss, and very little extra performance, if any.

PE Summit - 1 lever, no parts to get fouled, go bad, need replacing. No fussing with cat engagement lever. No worries about whether you're engaging the cat too early, too late, will it get up to 1200 and cause a fire?

Sure sure, we all could easily master the 2nd lever, but why bother?

In a rush? Need to get to the store? Throw 5 splits in your Summit, put the lever on about 70%, and head out the door.

What do you do with a cat? Sit there and wait for the temp to get to X? Or what? You can't use it?

Wake up with the Summit - throw on 2 or 3 splits and let it simmer on medium for a few hours. I burned all sorts of ways in my Summit - hot and quick, slow and not so quick. In the red. In the orange. One stick, two stick, three stick four.

1 season with a 33' stack, burning all different ways, got maybe 2 cups of ash out when I cleaned it.

Cat efficiency numbers are probably very inaccurate - they're tested with "EPA test fuel", which is nothing like cord wood, they need to be monitored and run correctly to get peak efficiency, and they are likely no more efficient for the burning you'll do 4 months a year in the lukewarm months when you only want a little heat output and you have no need to "fire up the cat."

To all you cat aholics - bless you - enjoy your cats. And your slide rules and typewriters.

 

[MovingOffGrid]

I'm sold (except for that flimsy little ash lip tacked on the front ) ... and to what do you attribute the excellence of the Summit over the Regency? the firebox design of the SS baffle versus Regency's Vermiculite? I must say I prefer the tank like door, ash lip and overall sturdy welded build of the Regency 3100, but the Summit seems to have many thrilled with the burn (you can't all be on commission can you?) lol

Ash pan or no ash pan ... ?

 

[begreen]

I'm surprised at the ash lip comment, the ash lip on the T6 is fine. However, IMHO, the ash pan on the PE is not. It is a great stove, but they could totally leave off this and sell the stove for a couple hundred less or make a usable system. That isn't a reason not to get the stove, but plan on shoveling out ash which is messier than a proper ash pan system.

 

[MovingOffGrid]

The T6 ash lip looks pretty skookum, but I haven't seen one up close. The ash lip on the Summit pedestal however, is lightweight, bendy and flexible - I could easily bend it with my hands as it's just screwed on, unlike the welded on tank like ash lip on the Regency that you can stand on.

Thanks for the feedback on the ash pan ... I may just save the money then and forgo it. Still hoping someone can tell me that the Summit is so much superior to the Regency in the burn that I will like it better, dainty little ash lip and all ;-)

 

[North of 60]

[quote author="Ivy, Frank" date="1233384613"
Cat efficiency numbers are probably very inaccurate - they're tested with "EPA test fuel", which is nothing like cord wood, they need to be monitored and run correctly to get peak efficiency, and they are likely no more efficient for the burning you'll do 4 months a year in the lukewarm months when you only want a little heat output and you have no need to "fire up the cat."
To all you cat aholics - bless you - enjoy your cats. And your slide rules and typewriters.[/quote]




You boast simple operation and no moving parts. What is this thread all about.
Well now I know you have no clue. You have got it backwards my friend. Those luke warm months is when the CAT is most advantageous. The whole idea is to be able to run at lower temps cleanly, and thats what they do. Ill bet it takes me less time to get my cat lit @ 500 and stove turned down and burning clean before you get your 1000f secondaries going. Every time somone mentions CAT in a thread you have some rude remark which is false. Yes I do also make comments but mostly understood in fun. They have to be monitored. Give me a break
Sorry to the rest of the members for my rant & good luck with your testing. Waiter, CHEQUE PLEASE. Iam outa here.

 

[Hogwildz]

The ash lip is just that. Its meant t stand on, load ten ton on etc. Its to catch ash that falls out when cleaning, reloading etc.
Both are great stoves. Tow things I will point out, is the Summit has a floating firebox. Less chance or warpage &/or welds cracking due to it having a ton of unnecessary welds that are avoided with the Summit.
The more welds you put on a firebox, the less moving room you allow it, the more chance that one of these areas will crack under extreme heat or stress.

I believe the Summit is actually less expensive than the Regency also.
Again, both have many happy owners on here, so do your research and choose what is right for you.

Just remembered a post on Regency's.
Not knocking Regency, just something you may want to read.
https://www.hearth.com/talk/threads/33940/

 

[begreen]

OK, in spite of it getting a bit too warm today to experiment, this thread pushed me on. With 41 degree outside temps and 30.17 steady baro reading, here are our results today. The timing is a bit erratic, I had work to do. What surprised me is the EBT engaged. As noted previously, the first fire of the day reached 650 stove top temps and the EBT didn't budge. For the second fire I loaded it about 3/4 full, e/w, with soft maple. Temps are as follows. I used the stove top thermometer and an IR thermometer on the hotspot next to the EBT. All temps are in degrees F.

1:20 pm - stove loaded on hot coal bed - EBT closed - EBT temp = 340, top temp =450
1:45 pm - stove burning vigorously - EBT closed - EBT temp = 360, top temp =550
1:55 pm - stove burning strong with full reburn - EBT closed - EBT temp = 370, top temp =625, closed air lever all the way off
2:15 pm - serious fire going, full reburn - EBT closed - EBT temp = 387, top temp =675
2:45 pm - steady reburn, fire quieting down - EBT 1/4 open - EBT temp = 394, top temp =600
3:10 pm - steady reburn, fire quieting down - EBT wide open - EBT temp = 385, top temp =550
3:35 pm - steady reburn, fire quieting down - EBT wide open - EBT temp = 401?, top temp =510 ( I should have put a bullseye target for the IR therm)
4:00 pm - slow reburn, fire quieting down - EBT 1/2 open - EBT temp = 372, top temp =475
5:00 pm - mostly coals burning - EBT 1/4 open - EBT temp = 350, top temp =400
5:30 pm - just coals burning - EBT fully closed - EBT temp = 342, top temp = 375

So the EBT is working and apparently in the cam like fashion that Tom has illustrated on his website. A couple conclusions:
1) The EBT should be adjustable for softwood vs hardwood. The range seems a bit high for softwood burning (which is what is available in PE's home turf).
2) EBT is a bit of a stretch, I'm not sure how much it extends burn time at all. But it probably does help burn down coals.
3) This makes me wonder how well the EBT would work if there was cold, 0 degree air coming in through an OAK.
4) So far I'm not consistently seeing the legendary PE long burn times. This test was a 4 hr burn with the stove about 3/4's full. OK, it's 7pm now and there are just enough coals to start a good fire. Stove top is at 250, so give it an extra 90 minutes, but at 5.5 hrs., this is not great. My observation is that the stove is feeding too much air, maybe my draft is too good for softwood. Tomorrow I'm thinking of putting the draft damper back in to see how that helps. Next season I get to burn hardwood. Can't wait.

 

[Hogwildz]

What I find interesting is the tests seen so far, There is not much of a steady temp at any time.
I have seen my Summit cruise at 650, 700 for a few hours. Course thats with oak & hardwood

 

[begreen]

I've seen a steady 650 for 2-3 hours with just the right loading of fir. But in normal operations, it seems the stove provides too much air for softwood. Today's load raged for an hour. I wanted to cut back the air but it was all the way closed. Next I'm going to try it with the stack damper to see how that works.

 

[10-cc]

Here is My test:
9:45 ==> lightup the T6 air inlet full open. stove loaded 3/4 full of sugar Maple, extirior temp 10 deg. F windy and clear. EBT close.

10:30 ==> stove top temp: 650, I close air inlet all the way. EBT still close.
10:45==> Stove top temp still at 650 and EBT still close.
EBT never opend when stove is hot (605 F)

I will let it stay that way(ait inlet closed) and monitor the EBT for the next houres and let you know.