VC Defiant Hybrid now available

[Gridlock]

I was at a local stove shop over the weekend, and noticed VC's new hybrid stove, which seems interesting. It is a combination of their CAT and Everburn technology rolled into one stove. The Everburn is always engaged, but the user has a choice of whether to run it with the CAT or not. The dealer mentioned that it allows the user to wait for a while in purchasing a new CAT combustor when it needs replacing, or not run with it at all. It also lowers emissions to a lower level when both are engaged.

It does seem like an interesting design, but wonder how well it will work if the smoke is so choked by having to pass through two exhaust systems. I wonder if VC decided to create this stove for some upcoming new federal regulation, since I bet a lot of people remove and never replace the combustor in the CAT stoves.

 

[branchburner]

They were talking about this at the Woodstock open house. One of the fellows was under the impression it was an either/or, that the user could choose to operate it as either cat or non-cat, but it would not automatically transition to catalytic when the secondaries ceased - so was not really a hybrid in the same sense as the new Woodstock would be. But I think he was just speculating.

There seems to be nothing about it on the VC site - the only thing I've seen is this thread:
https://www.hearth.com/econtent/index.php/forums/viewthread/56347/P22/

 

[Gridlock]

Yeah, it's curious that there's nothing about it on VC's site about it, when I saw the unit at the shop. It did give me the impression that it was a step up as far as build quality; little things like a redesigned front door latch with a roller ball that 'snaps' into place when full closed. I didn't notice traditional fire brick either, but the CAT and everburn were hidden from view. I did notice the traditional damper handle, so it does appear the the engagement of the CAT is still a manual process.

 

[Todd]

So, are you going to buy one and be our guinea pig?

 

[Gridlock]

So, are you going to buy one and be our guinea pig?

Ha! I might be a bit of a masochist, but that may be more pain :shut: than I'm willing to inflict on myself! If my current VC starts acting up again, then I might be seeing Woodstock's new stove in my crystal ball (I might lean to a BK stove, they are just so fugly). Hopefully the new VC stove will work great and be a new beginning for them.

 

[branchburner]

Dug around a little, and there is a Defiant 2N1 and an Encore 2N1 - here is the Encore manual:
http://literature.mhsc.com/vermont_castings/manuals/30005295_Encore_2N1_2.pdf

Looks like the cat is placed right in the afterburner in the back of the stove. There is a primary air control and a bypass damper. Since the cat will start burning smoke well before there are sufficient temps for the afterburner to kick in, I wonder, what is the point? Maybe the idea is that once the cat fires, it helps boost temps in the chamber to get a quicker secondary combustion to burn whatever gasses the cat does not.

My guess is that VC wants the efficiency numbers of the cat, but they want the ease of marketing a non-cat, so from that perspective it's the best of both worlds. As for functionality, I'm confused.

 

[Todd]

The manual states not to burn full loads of very dry wood and 18 month split and stacked wood could be considered to dry which could cause damage to the combustor. They also say to mix in green wood if yours is too dry. Sounds like they are not too confident about the durability. No way is 18 months too dry unless you live in a desert. I can see problems already, "your wood is too dry and you overfired the stove".

 

[branchburner]

The manual states not to burn full loads of very dry wood and 18 month split and stacked wood could be considered to dry which could cause damage to the combustor. They also say to mix in green wood if yours is too dry. Sounds like they are not too confident about the durability. No way is 18 months too dry unless you live in a desert. I can see problems already, "your wood is too dry and you overfired the stove".

Yeah, I though that insanity was worthy of its own thread:
https://www.hearth.com/econtent/index.php/forums/viewthread/60281/

 

[jeff_t]

Really? Wow. A manufacturer of modern stoves saying your wood could be too dry? I would have to scratch that one off my list.

 

[Slow1]

Interesting none the less - whatever their design is I find the fact that two companies are now looking to have a cat/non-cat hybrid stove on the market noteworthy.

Well, given the number of people out in the world I'm sure eventually someone who buys one of these stoves will get on the forum here and we can grill them for information eh?

 

[Todd]

Too bad Elkimeg isn't here anymore, he always had the inside scoop from VC.

 

[begreen]

There were some good nuggets noted, but unfortunately they sometimes got lost in the VC-can-do-no-wrong reporting.

 

[CTBurner]

The new system also will fit in NC encore-defiant models

 

[maniac424]

According to the VC dealer, the CAT does not come into play until you flip the damper, which you do once the stove has reached the correct temp. To burn it as a non CAT you just remove the CAT. The specs for the Two-in-One stoves are as follows:

Encore Defiant
CAT- 86% Eff. @ 1.2 g/hr 84% @ 1.1 g/hr
Non CAT- 78% Eff @1.5g/hr 76% @ 2.3 g/hr

Seems pretty impressive in either mode.

 

[branchburner]

To burn it as a non CAT you just remove the CAT.

Interesting. That's what the guy at Woodstock told me, but I didn't get that impression from the manual. Not a word about removing the cat for anything other than cleaning or replacement. So it appears that maybe it is not really a true hybrid in terms of function, but instead it is either a cat or a non-cat at the operator's discretion?

 

[jharkin]

[quote author="branchburner" date="1288125866"So it appears that maybe it is not really a true hybrid in terms of function, but instead it is either a cat or a non-cat at the operator's discretion?[/quote]

I would guess so. If you look at the manuals for the old Encore, in the exploded view the layout is similar for both. In the catalytic, the catalyst sits where the everburn chamber is in the non-cat. Im thinking the major difference in the two was the shape of the burn box and the volume of secondary air.

They must have figured out a way to fit a catalyst into a burn box shape that also works for everburn.

 

[Gridlock]

According to the VC dealer, the CAT does not come into play until you flip the damper, which you do once the stove has reached the correct temp. To burn it as a non CAT you just remove the CAT. The specs for the Two-in-One stoves are as follows:

Encore Defiant
CAT- 86% Eff. @ 1.2 g/hr 84% @ 1.1 g/hr
Non CAT- 78% Eff @1.5g/hr 76% @ 2.3 g/hr

Seems pretty impressive in either mode.

Interestingly the specs for the current non-hybrid CAT Defiant is 90% Eff. @ 0.8 g/hr, which is substantially better than the newer hybrid model. Not sure why unless the specs are just not very accurate.

 

[Backwoods Savage]

Interesting you can burn with the cat or without. Well, we do that quite a bit with ours already. If not much heat is required, we simply do not engage the cat. No rocket science there....