VC Technical memo

[Shane]

Was reading through some stuff today and found a tech memo from Vermont Castings concerning the glowing on the rear of the Everburn systems and the Resolute. They said that the flue gasses hitting the back wall at such high temps will cause this and that areas have been re-inforced to handle the beating. I know this has been mentioned before but, if my memory is right, there was a question as to whether VC actually said this or not. And they did I have the document in hand. So it seems that they knew about it and it was addressed in the manufacture of the stoves.

 

[webbie]

Interesting.

This is one of the main compromises made for top loading. When you top load,the front and top of the stove is, by nature, relatively cool. The design mandates that the real action must take place in the rear of the stove - that being the exact place where you usually don't want all the heat to go. Then again, we see from the dutchwest large top clearance that there are problems when the heat is pushed out the top too!

The solutions are numerous including convection designs, heat shields, larger heat exchangers and designs which allow heat to radiate from as many surfaces as possible, so as to dissipate (spread) the heat around. Having a larger number of sq feet of stove surface at an even temp may beat having a small area at a very high temp.

If the first resolute acclaim and other coal stoves (sudiac, etc.) are any guide, there is no amount of beefing up that can solve a problem of cast glowing red on a regular basis. I will have to look carefully at the design to see what is likely (if anything) to fail.

Remind me - are the parts that glow easily replaceable, or are they the rear plate of the stove, etc.?

This illustrates the dilemma of engineering, which I'm certain cast and corie can explain better than I. When you do one thing, it causes another! Beef up the bridge for heavy traffic, and now the foundations or something else fails.

 

[Shane]

Not easily replaceable parts at all really. Were talking the rear wall of the stove, and the flue collar can have a dull glow. I guess the flue collars are easy enough to replace. The thing that interests me most of all is that the Resolute Acclaim is thrown into this mix. That stove has been around for years and we've sold alot of them. I've never had a customer mention glowing rear cast. This all seems strange to me, I guess the most important thing here is that the factory knows and acknowldeges the situation, so when and if warranty issues arise surely they're going to graciously cover such things.

 

[webbie]

VC has always been good - perhaps the best - at taking care of warranty issues. However, as they have found out (and dealers/consumers also) it is MUCH cheaper to fix the stove before it is sold. Even if VC sends the parts for free and pays some labor, what is the true cost of removing a 400 lbs stove and rebuilding it? VC (and no other manufacturer) never pays this price. That means it is out the dealers pocket.

The acclaim had the rear 100% protected by the ceramic box. I assume the everburn must not? Or does the glow come right through the ceramic to the rear plate?

This would be a great application for a "back boiler" - those hot water systems popular in Europe. You could run a couple radiators and the DHW off of it!

I have to get out more often...and, in this case, look carefully at this stove. I think I will pay a visit to some of the local shops soon.

 

[elkimmeg]

they insulate the rear secondary combustion chamber with the same insulation that surounds the molten cast iron kettles.
As things evolved it seems the ash dump door hinges got sprung arring too much air to the fire box and also the flue collar connection. with the frue collar conection c crimping is 1.5" and the dept of the collar insertion is 1" the space or low point in the crimping acted like an air leak causing overfireing now if one took 1/2" off the length of the crimping and pushed it into the rib of th connector pipe the issue is solved or gasketed cemented the connectioin that too solved the collar connectioin. Since these two discoveries have been anounced the problem has gone away.