Firebox Temp

[bholler]

Thanks, understood - most I’ve been looking at don’t really give a stove top or pipe temperature to go by either - perhaps just a note to make sure it doesn’t get so hot that the outside components start glowing red. That 1400F+ mark seems to be around the lower end of concern for some components so trying to determine how common 1400F+ would be for glass or at the top of the firebox if the stove and pipe were not glowing red outside, and / or stove top temps were kept around 700F (based on what I’m reading) or less as a start / example.

I don't understand what your worries are regarding this

 

[kborndale]

A stove will start to give a faint visible glow around 850-900 F. That's only really visible in the dark at that temp.

 

[GoStove]

Thanks. Sounding like the suggested stove top temps I see here on the forum would stay well below the glow. Curious what glass and firebox temps are at that point. Wonder if there is any truth (at all) to the old firebox = 2X stove top temp rule of thumb. I’m sure it doesn’t help that most infrared thermometers I see max out at 1100-1200F (with some exceptions)…I think we’ve established based on secondary burn that 1100F is common, curious if that 1400F+ range even happens at all or all the time etc.

 

[NickW]

There is for sure some thinking going on, but to keep it simple I’m really just trying to determine if the glass and components at the top of the firebox get to 1400F+ if stove top temps are kept reasonable, perhaps 700F or lower. Not sure how accurate the old 2X rule is or what even the typical temperatures might get to during a brisk burn etc.

My GUESS would be yes, it is possible inside the firebox in some areas. Maybe the inside surface of the glass? Outside glass surface or past the baffles probably not...?

As others have pointed out, there are many variables that will affect temperatures of various components in a system. Different areas inside the firebox will be different temperatures. A catylist could see 1400 degrees I think. Secondary combustion tubes possibly? I know my tubes glow when it's really ripping.

Is there a reason you are concerned with this particular temperature inside the firebox? Stove components are designed to withstand normal operating conditions. Normal operating conditions are maintained by controlling air flow.

 

[NickW]

I see others responded while I was typing...

1. Get ahead on your wood supply.

2. Pick an appliance, determine the minimum minimum flue height required versus what your flue height will be, determine if any elbows are needed which will reduce draft, install a damper if there's any question that draft might be strong...

3. Happy burning!

 

[bigealta]

Sounds like you really want a durable stove that can take a lot of abuse.

I'd focus on asking for that rather than trying to deconstruct what in your mind may or may not happen in a future stove and trying to predict damage potentials.

Tell us;
How tall is you existing chimney or chimney to be built
Internal or external chimney
Location of stove in house, what floor, basement or main floor
How big a space do you want to heat
How well is house insulated.

Or are you asking these questions because you are fabricating your own stove?

 

[GoStove]

Thanks guys to hopefully catch up on some questions we are looking at 20-25’ total pipe straight, basement install. Pipe inside except exposed chimney. This would be a larger around 3+ cubic foot non catalytic stove, if our other heat sources have to back us up a bit that’s ok, and I would rather keep the stove within range than push things past their limit if that makes sense.

That 1400-1500F range seems to be around the lowest of temps it sounds like it’s best to not exceed for some of the internal components and now I am also just frankly curious on firebox temps at this point. Most manuals just say keep it from glowing, sounds like that’s about 850F outside so I am wondering if you stay below 850F if we’re below that 1400-1500F range in the firebox. But sounding like I would want to keep stove top temps quite a bit lower than that from what I’ve read, 700F or less sounds ideal for most stoves from what I’ve read on here so far.

Obviously sounding like the first thing I’ll be getting after install is an infrared thermometer that goes that high but I am curious if anyone else has measured their firebox temps and possibly in relation to their stove top temperature. Thanks for the input.

 

[EatenByLimestone]

25 feet is on the tall side, but if you’re at altitude it’s effectively a shorter chimney.

 

[NickW]

1. Install a damper. That's pretty tall.

2. IR can't measure accurately through glass and once you open the door the temps will drop. You can't measure firebox temperature without expensive equipment. Install a digital flue probe to monitor flue temperature and a magnetic stovetop thermometer (not a stovepipe thermometer) and/or use an IR gun to monitor stt.

3. I personally rarely run stt over 650 in my tube stove although some guys do.

Well seasoned wood is the biggest factor in successful burning. Poorly seasoned wood is the #1 reason for struggling. Regardless of what a firewood vendor claims, assume his wood is NOT properly seasoned.

 

[bholler]

Thanks guys to hopefully catch up on some questions we are looking at 20-25’ total pipe straight, basement install. Pipe inside except exposed chimney. This would be a larger around 3+ cubic foot non catalytic stove, if our other heat sources have to back us up a bit that’s ok, and I would rather keep the stove within range than push things past their limit if that makes sense.

That 1400-1500F range seems to be around the lowest of temps it sounds like it’s best to not exceed for some of the internal components and now I am also just frankly curious on firebox temps at this point. Most manuals just say keep it from glowing, sounds like that’s about 850F outside so I am wondering if you stay below 850F if we’re below that 1400-1500F range in the firebox. But sounding like I would want to keep stove top temps quite a bit lower than that from what I’ve read, 700F or less sounds ideal for most stoves from what I’ve read on here so far.

Obviously sounding like the first thing I’ll be getting after install is an infrared thermometer that goes that high but I am curious if anyone else has measured their firebox temps and possibly in relation to their stove top temperature. Thanks for the input.

An infrared thermometer isn't going to give you accurate readings through glass. Unless you spend thousands of dollars on monitoring equipment you will never know internal temps. And it will never matter. Just get a simple magnetic thermometer for the stovetop and either a magnetic or probe thermometer for the pipe. (Magnetic for single wall probe for double) that is all the data you need to have to know if you are running properly.

 

[GoStove]

Thanks. Not looking to measure through the glass, but perhaps the glass itself and baffle areas with the door open to make sure temperature ranges are within limits. Not sure how fast those temps would drop upon opening the door. Had not considered that. Sounding like we are in somewhat uncharted waters here, ha. Maybe the 2X stove top temp “guess” is better to go by.

 

[bholler]

Thanks. Not looking to measure through the glass, but perhaps the glass itself and baffle areas with the door open to make sure temperature ranges are within limits. Not sure how fast those temps would drop upon opening the door. Had not considered that. Sounding like we are in somewhat uncharted waters here, ha. Maybe the 2X stove top temp “guess” is better to go by.

The baffle is going to drop a couple hundred degrees the second you open the door. I am positive the stove manufacturer’s have done the internal temp testing. But they don't give it to you because it is irrelevant to the end user.

 

[stoveliker]

Yeah, if you are doubting the design of the stove, and its (UL) safety testing, and that is why you can't live with the instructions that came from them, then don't get a fire in a metal box in your home...

 

[GoStove]

Not doubting any of that at all - just curious regarding what types of internal temperatures are experienced inside the stove and if that can be monitored via stove top calculation, approximated by rules of thumb, and so on, so that I can make sure to not exceed the temperature ratings of the internal components during use (and also am just plain curious at this point as it seems to be a bit of an unknown).

 

[EngTechnow]

Glass on VC -0044 is seeing 495F~545F most always and when Running few Hours 635F has been Hit ..
I'm usually Only Running in Mid Load Range , so about 35,000 BTU's , I Believe it's Rated @ 42K BTU's but with Coal
55K BTU's back then Blue Flames & Good Pile Coals would Drive Us right out of Living Room & Running around in Under Wear . .

 

[stoveliker]

Not doubting any of that at all - just curious regarding what types of internal temperatures are experienced inside the stove and if that can be monitored via stove top calculation, approximated by rules of thumb, and so on, so that I can make sure to not exceed the temperature ratings of the internal components during use (and also am just plain curious at this point as it seems to be a bit of an unknown).

Has been answered
No, outside temps cannot be used to derive inside temps. Too many variables.

To make sure you don't overfire the stove, measure your draft and ask your mfg what draft you need, then play with a key damper if needed.
Other than that follow the operating instructions.

You're not asking the same questions about your microwave either, right?

 

[NickW]

Not doubting any of that at all - just curious regarding what types of internal temperatures are experienced inside the stove and if that can be monitored via stove top calculation, approximated by rules of thumb, and so on, so that I can make sure to not exceed the temperature ratings of the internal components during use (and also am just plain curious at this point as it seems to be a bit of an unknown).

Maybe you could contact the manufacturer for the test data, then make guess adjustments for flue and environmental variations?

 

[EngTechnow]

I Use an IR Gun , & I just got IR Camera Gun as - Pin Point was Unit is Like Chasing Needle in Hay Stack - when Looking for Air Leaks ..
I have had 54ft Chimney where unit was at 46ft & 35ft Height on another so Unit was only 24ft
Currently 40ft Chimney Unit is @ 36ft , but there is at Least
5ft more Below Grade to into Basement & Footer .. as there's a Gas Unit in Basement . On Back side I had to Fill Crawl space that Base is In so I was in & Out of that Area bunch Times - also Insulating Freeze Board Area . . as there was Nothing !
But I'll leave all that for Another Time ..

Anyhow I have Never Had an Over Fire Condition As I Placed 5.5Ft long Oval to Round ( SS-Titanium Pipe ) Special that Necks Down to
Less then 5" Opening , this all Goes up inside Smoke Chamber . . even with that I Throttle Down Air Controls . . as Flues Here are 12.75 x 12.75 .. Older Homes - Flues were Smaller ..

In_fact I have been Thinking about one of those Chimney Hanger's Objects that Act as Muffler so Keep More of Heat in Lower section Chimney ..

 

[GoStove]

Sounds like we know firebox temperatures of at least 1100F can be reached but peak temps are still a bit unknown. As far as following the manual don’t get it red hot...I think I’ve read a few on here saying that internal component longevity would be shortened substantially before a red hot (outside) temp was reached, based on stove top temps mentioned, but I would think it is really internal temp that matters more here and stove top temp is being used as a general guide to that.

Manufacturers would know more I’m sure, I’m curious in general / average / theory as a baseline as well for wood stoves. Curious to learn more if anyone has any more data or experience they’ve seen on firebox temps.

 

[kborndale]

I Use an IR Gun , & I just got IR Camera Gun as - Pin Point was Unit is Like Chasing Needle in Hay Stack - when Looking for Air Leaks ..
I have had 54ft Chimney where unit was at 46ft & 35ft Height on another so Unit was only 24ft
Currently 40ft Chimney Unit is @ 36ft , but there is at Least
5ft more Below Grade to into Basement & Footer .. as there's a Gas Unit in Basement . On Back side I had to Fill Crawl space that Base is In so I was in & Out of that Area bunch Times - also Insulating Freeze Board Area . . as there was Nothing !
But I'll leave all that for Another Time ..

Anyhow I have Never Had an Over Fire Condition As I Placed 5.5Ft long Oval to Round ( SS-Titanium Pipe ) Special that Necks Down to
Less then 5" Opening , this all Goes up inside Smoke Chamber . . even with that I Throttle Down Air Controls . . as Flues Here are 12.75 x 12.75 .. Older Homes - Flues were Smaller ..

In_fact I have been Thinking about one of those Chimney Hanger's Objects that Act as Muffler so Keep More of Heat in Lower section Chimney ..

I'm having a difficult time reading what you are trying to write.

 

[EngTechnow]

Sorry _ I'll _ leave _ More _ Space

On Glass of VC -0044 is seeing 495F~545F most always and when Running few Hours 635F has been Hit ..
I'm usually Only Running in Mid Load Range , so about 35,000 BTU's , I Believe it's Rated @ 42K BTU's but with Coal
55K BTU's back then Blue Flames & Good Pile Coals would Drive Us right out of Living Room & Running around in Under Wear . .

Seen Temps of 635F on Glass , I Just got IR Camera's , so I have Not Yet Taken Pictures of VC
Been To Bust Chasing Leaks in Old Home .. 2X = 1270F

 

[GoStove]

Thanks for the info, would be quite interested to hear what you’re getting inside the stove.

 

[EngTechnow]

I'm Sure it's Nowhere nest to what Newer Designs are Getting - especially with Cats

My Old Coal Grate Burning Wood ..
as I have Secondary Layer Out - I have some Extra Parts laying about somewhere that My Other Half has tried to Throw Out at least Twice . .

Remember VC F- 0044 was Before Computers and many Spend 3 days doing math , & Another 3 Days doing Drawings . . I was in Training at Time in College & First Full Time Job after School . .
Melting Old High Nickle Big Blocks , what some Term to be PH4 Used Today 2000's Turbo Housings . . now those 321SS & Ni Based Super Alloy's

Mostly 495F on Old 2685F Fired Ceramic Quartz Glass . . Rated @ 2250-2300F something . . If I recall ..
More Like 895F ~1000F most Time , but Really Don't Know - Exact #
- I'm still getting use to even Shooting the Small IR Camera on some Items it seems
On other Items ~ Like ~ E-Coated Windows It Flips Out . .

 

[bholler]

I Use an IR Gun , & I just got IR Camera Gun as - Pin Point was Unit is Like Chasing Needle in Hay Stack - when Looking for Air Leaks ..
I have had 54ft Chimney where unit was at 46ft & 35ft Height on another so Unit was only 24ft
Currently 40ft Chimney Unit is @ 36ft , but there is at Least
5ft more Below Grade to into Basement & Footer .. as there's a Gas Unit in Basement . On Back side I had to Fill Crawl space that Base is In so I was in & Out of that Area bunch Times - also Insulating Freeze Board Area . . as there was Nothing !
But I'll leave all that for Another Time ..

Anyhow I have Never Had an Over Fire Condition As I Placed 5.5Ft long Oval to Round ( SS-Titanium Pipe ) Special that Necks Down to
Less then 5" Opening , this all Goes up inside Smoke Chamber . . even with that I Throttle Down Air Controls . . as Flues Here are 12.75 x 12.75 .. Older Homes - Flues were Smaller ..

In_fact I have been Thinking about one of those Chimney Hanger's Objects that Act as Muffler so Keep More of Heat in Lower section Chimney ..

So you are just dumping into the smoke chamber of an open fireplace?? How is your pipe sealed into the 12x12 flue? Is that 12.75x12.75 lined??

 

[EngTechnow]

It's Long Enough to Get 14" Up into that Flue @ Least - Tapered & Tight Fitting as Pipe is Large _ I Cut a 1ft Slot into It
40yrs ago to Form Taper . .
I did 2 Different Investigations into Attic Area of Breeze Way / Den
Room that Heads to Dual Garage which is on Pad .. Above & Below - Twice Each . . with Tubs of Fire Clay . . I did Find
2100F Degree stuff & Pulled Lose Mortar Off Smoke Chamber Built Out _ & Brick up in Small Crawl Attic - might be 5ft in Middle
I went through 4-5 Tubes of that..
When I Pulled Gas Unit I Mixed Fire clay & also repaired some Fire Bricks - that - were in Original Fire Box Below Smoke Chamber ..
Added in a Good Layer & there about 4" on Sides & 12" Above VC Insert then Smoke Chamber Begins .. on Bottom there was at Least
35 lbs of White Sand in Back away from Hearth 0044 Wheels Rolled into that . . Nicely but Pipe was a " B " getting into Position . .
After several Adjustments & Pulling on Inside Handle Thank God for that Great Pipe . . as It's a Dual Flue & with Fireplace in Basement
There's a Dog Leg in Chamber . . Which Allowed Me to Climb Up on this Beast & Ride , Oh Joy 2 Days Later . .

In Fact I'll be Doing another Trip Up into this Area with IR Gun in Back Pack with Tools & 4 Cans of Fire Foam as I have Found a Big Leak . . Between ( Cold Air ) Leak which Leads to South gable wall . . also be Up in Main Attic to check on that Gable Area as Original Builder Fiber Boarded It - Both Outside & Inside = No Insulation . . ( Issue Yet to be Determined )
Upper - & - Lower Wall ~ First Floor Ceiling at Back Side of this " Chimney " in Question . . Any & All Suggestion more
Then Welcome as I'm always Learning . . Please . .

There has been some Settling of Home of 40 yrs as to Poor Control of Water & Flash Flood Events ~ Which has Taken Me 4 Yrs to get a Handle on All of That !
( Another Big Under Taking ) Hence 9 Ply White Vapor Barrier & 40 Bags of Smooth Round Rocks Plus My 2 Loads of Bricks on Bottom ..
Water Controls out side - I could Fill a Book as Home is Positioned on 8-11 Degree Slope , Luckily were 85ft above all Low Land . .
Plus Another 100ft Higher then "Really Low Area's " about 1/2 Miles Away - that Do Flood from Time to Time ..