HyFireI design questions

I'm looking into a new stoker and a buddy has the hyfireI so I've been studying his. This has left me with some design questions I thought maybe someone could answer.

Question 1: The hyfire 1 has a 40k and 90k BTU burner. While my buddy knows which one is which, I can't see the difference between the two. The grates look exactly the same size. In fact the HyfireII grates look just like the grates in the Hyfire1. Maybe someone can explain where the BTU difference comes from.

Question 2: The hyfire at my buddies house has two port holes on the front that have a little cover over them that can be removed. There is also a gap under the top lid to allow air to blow over the top. Now it looks like the port tubes go inside the fire box so that's probably the "internal heat exchange". My question is, why have both? Wouldn't you want all the air to move through the internal tubes? In fact my buddy keeps the tubes capped so all the air comes out from under the lid. It seems to me you would want the opposite and have all the air go through the heat exchange. So why both air routes?

Thanks!

Hi Bill,
If the grates are the same size, then the stove is a Hyfire II. The 40 grate is much smaller then the 90 grate.
The main reason for the 2 ports is to get heat into the basement if your hooked into a hot air jacket. With a jacket 85 % of the heat is being put into your duct work. some people want a little extra heat in the basement. So we built 2- 2x4 tubes as small heat exchangers through the stove. You can open 1 or 2 or none, but we have them there for that little extra. I talk with people everyday, everyone wants the applacation a little different. We do as much as we can without adding too much cost to the stove. People burn coal to save money, if the payback of the stove takes 20 years, well then it just not worth all the extra work. Have a good day.
Jerry

Thanks for the info jerry.

The grates are indeed the same in my friends unit so he must have the HyfireII. It was there when he moved in so he must have just been uniformed.

I also like the idea of being able to snap in or out the covers for those holes. I don't think anybody wants to see the contraption I had to make on my handfired alaskin to perform the same service.

Ok, but I do have one more questions. I don't see any efficiency ratings posted anywhere. Can you give a rough estimate for you stoves? Just general...you know like 75%, 80% or 90%

After speaking with several dealers I kinda get the idea that comparing BTUs is like comparing mattresses. Some rate output, some rate input some rate efficiency of input. Just trying to get an apples to apples comparison.

-Bill

Bill,
We have an effic. of 80/83%. Alot has to do with the fuel. Coal is just like gas, regular , medium grade or high test. It all looks the same to me.
Thanks for looking at our product.
Jerry
Remember, you need heat to create a draft. Don't be fooled by the high numbers.