Condar FlueGard Questions

[Duds13]

I recently ordered a Condar Fluegard and installed it yesterday. Couple questions for the experts:

1. For the first cold start with the new Condar, I did a top down start so the Flurgard temps reached the red on the dial before the BK cat probe reached the active stage. Do I close the bypass when that happens? The cat probe did catch up to the Fluegard rather quickly so I didn't feel that I reached troublesome temps on the Condar.

2. This morning cat probe was right at the inactive/active part of the dial. Fluegard was middle of the yellow. Loaded the stove with wood and as it got going the cat probe reached active stage before the fluegard rached the orange stage. In this example, do I close the bypass based on the cat probe being in the active stage, or do I wait until the Condar reaches the orange stage?

This is a BK Ashford 30.2

Thank you!

 

[Highbeam]

On warmup when either the flue Meyer hits 500 or the cat meter hits active, I close the bypass.

Same for #2. Your cat wants 500 degree smoke and if either of those meters tells you that 500 degree smoke is present then close the bypass. Then leave the thermostat on high for the burn in.

The best use of the new flue meter is to never run your flue in the red zone. Your class A is rated for continuous exposure to temperatures up to 1000F.

The second best use for that flue meter is to maintain a high enough low burn rate that you don’t gunk up your flue with cold exhaust. I like to maintain 400 or higher on my fluegard meter.

 

[Duds13]

Awesome, thank you very for the information!!

 

[Tron]

The BK cat gauge is very laggy. I usually wait until flue temps are somewhere in the orange and then I close the bypass.
Cat usually catches up very fast and I see it glowing within a minute or so, which tells me what @Highbeam already said, that the smoke is hot enough for the cat to engage.

 

[Highbeam]

The BK cat gauge is very laggy. I usually wait until flue temps are somewhere in the orange and then I close the bypass.
Cat usually catches up very fast and I see it glowing within a minute or so, which tells me what @Highbeam already said, that the smoke is hot enough for the cat to engage.

The typical flue probe meter with the bimettalic coil is laggy too when compared to a thermocouple so that helps too.

 

[stoveliker]

I thought the cat needed 600 F gases.
So I do the same as @Highbeam, just 100 degrees later (that is, close bypass at flue at 600 or cat is active, as I don't have numbers on my original BK cat probe).

I think this (flue temp higher than cat temp) will happen more when one has excess draft.

 

[Duds13]

Appreciate the additional input! Really glad I added the Condar.....it's a good feeling knowing I can run the Ashford hot during this cold spell with safe flue temps.

 

[Highbeam]

I thought the cat needed 600 F gases.
So I do the same as @Highbeam, just 100 degrees later (that is, close bypass at flue at 600 or cat is active, as I don't have numbers on my original BK cat probe).

Well here's a photo of why I go to 500 anywhere before closing the bypass. Even if you closed the bypass somewhat early, what's the real risk other than a non immediate cat glow?

 

[stoveliker]

Well here's a photo of why I go to 500 anywhere before closing the bypass. Even if you closed the bypass somewhat early, what's the real risk other than a non immediate cat glow?

View attachment 323094

I was not arguing with you, just confirming that your approach works (for me at 100 f higher).

Bkvp says 550. That's why I chose 600 - my own little safety margin...

Post in thread 'Time for cat #5!' https://www.hearth.com/talk/threads/time-for-cat-5.199912/post-2682360

I do believe Midwest says 500.

 

[stoveliker]

Btw, I do think that closing it a bit (too) early will get it up to active temps quicker because the hot gases go thru it rather than straight up the flue.

 

[Tron]

Even if you closed the bypass somewhat early, what's the real risk other than a non immediate cat glow?

Probably not much. You may deposit a bit of smoke particles on the cat surface when it's not active yet, but those should burn off quickly after the cat reaches operating temperature.

 

[stoveliker]

Probably not much. You may deposit a bit of smoke particles on the cat surface when it's not active yet, but those should burn off quickly after the cat reaches operating temperature.

Yes - if it's a little. In principle, once it takes too long (i.e. close the bypass significantly too early, and go to work for 9 hours), one can coat the cat, and that then needs significant primary heat to burn it off, which is much harder than burning off a little coverage using the heat generated by open active areas in the cat.

I'm not sure if people have coated cats like this in practice.

 

[Highbeam]

Yes - if it's a little. In principle, once it takes too long (i.e. close the bypass significantly too early, and go to work for 9 hours), one can coat the cat, and that then needs significant primary heat to burn it off, which is much harder than burning off a little coverage using the heat generated by open active areas in the cat.

I'm not sure if people have coated cats like this in practice.

I suspect we will eventually see a cat stove with no bypass. Cat always engaged. Perhaps the primary air not very adjustable or at least not as adjustable as the BK design in an effort to get the cat clean and active.

 

[stoveliker]

Maybe. But once folks start restricting the air inlet (think magnets and what not), one ruins the activity of the cat quickly (coating it), meaning it's a double whammy for emissions.

And I suspect that that would cause hesitation with the regulatory agencies to approve this. One bad action makes the result double as bad.

But maybe they don't think all that deep