"Top Air/Secondary Air Question"

Sunny Boy · Post by **Sunny Boy** » Sun. Feb. 01, 2015 8:08 pm

Well, if there are differences in depth of coal bed design from one stove model to the other, that likely is a factor. A deeper bed should need more secondary air.

Then there's other details such as how much preheating the air gets before it gets to the fire.

Are you comparing boilers to boilers, or boilers to furnaces ? Hydronic units tend to absorb heat out of a firebox more quickly for similar sized fireboxes. Water is about 26 times more efficient at removing heat for the same surface area then air is. That may have a bearing on how your stove's firebox was designed to have air delivery.

There's many small, not easily seen differences that can add up to a big difference in performance, and/or obvious differences in stove controls, etc. However, when doing any comparisons, those little things have to be accounted for, or you'll be scratching your head a lot !

Paul

hotblast1357 · Post by **hotblast1357** » Sun. Feb. 01, 2015 8:11 pm

I agree with you Paul, there is so many differences! It's hard to even start comparing stoves to stoves and houses to houses and chimneys to chimneys, we can just share our facts and differences and try too help anyone that ask for it.

oliver power · Post by **oliver power** » Mon. Feb. 02, 2015 4:16 pm

J F Graham wrote:Paul, I have given this a LOT of thought, given the way lee did his. However this being a boiler, and 1/4 inch steel I really don't want to mess with it. I kind of have it figured out, but it is more complicated than most. With this unit I not only have primary, secondary and also have idle air. Between the three and constant fluctuation of air flow it's a bitch to get a handle on. Not to mention all the fkn clinkers from this damn reading coal I can't ever have a "Constant" to calculate from. I have discovered that, at least in my case, secondary's are very important; but the settings seem to be extremely critical. Now go figure; probably the two most popular "hand feds" of modern production on this forum are the Hitzer and the DS circulator. Right?? Well please enlighten me, The Hitzer has NO secondary's, and the DS circulator seems to use 3 times as much secondary air as me.?????????? But both seem outstanding performers. WTF am I missing.
Jim

HITZER EZ-Flow stoves are strictly anthracite coal stoves, and have no secondary air. They will burn a low coal fire in the warmer shoulder months, as any, and all draft is pulled through the fire bed. The D.S. has over fire, secondary air. In the warmer temps, I can see the D.S. having problems burning a low coal fire, as the fixed secondary air has less resistance. However, with the over fire, secondary air, D.S. can burn wood during the shoulder months. Secondary air wash on the glass keeps the glass cooler, and cleaner, longer. I'll know better next winter, as I'm going to play with a D.S. in my shop. Meanwhile, the HITZER 30-95 is doing a fine job. Couldn't be happier with the HITZER. Shop will be doubled next year. Thought I'd play with D.S., now that we have a local dealer.