A little while ago I was able to connect with Rand Lindsly, from Trail Designs, to learn more about their popular Caldera Cone System. I had always thought of the Caldera Cone as an alcohol stove with a windscreen, but Rand was able to shed some light on the topic for me. He made some really great points and got me thinking about alcohol stoves in a way that I hadn't before. It's easy to tell that Rand and the Trail Designs team really understand the ins and outs of lightweight backpacking stoves. In his words "We pretty much eat, sleep, and drink this stuff every day, so we kinda got our heads around it."
Here's a brief section from one of our conversations with some interesting info on alcohol stove efficiency. If you're looking for a lightweight backpacking stove with high efficiency, Trail Designs is a great place to start your search.
In one of your previous write-ups you stated that the Caldera Cone's enclosed system will "decrease boil time." I can also tell that you are struggling with how to categorize it (stove with windscreen…but the windscreen is important…so it's not just a stove….so what do I do! :-)
These have ended up being two kinda important things we had to wrestle with over the years. First, "decrease boil time". For some reason boil time got a foothold in the mind of hikers as being somehow important. For lightweight folks, it is actually and literally the opposite of what you're looking for. As it turns out, the physics of the situation dictate that the slower you get to a boil, the more efficient you are (in other words the less fuel you burn). That ends up being counter intuitive to a lot of folks, but that's the way the thermodynamics work out. As a consequence, the cone is not there really to speed up boil times, but more to hold the heat against the pot longer to increase efficiency and milk as many BTUs out of the exhaust gasses as it can before we let them go. We tune our stove to give a reasonable boil time (7 to 8 minutes) but we actually slowed it down to that speed in order to boost efficiency.
Second is the stove/screen/cone/ confusion. We've been fighting that a long time. People want to think exclusively in terms of "the stove" and "this stove is efficient" and "this stove is fast" etc etc etc… putting the stove at the center of the universe. In the end, alcohol stoves really aren't all that different. People have figured out how to turn the alcohol into heat pretty predictably with a soda can. The trick is "the system"… not the stove by itself. What we figured out was that the important bit was less the ability to turn alcoholinto BTUs… but then what did you do with those BTUs afterwards… that's when we came up with the cone. So, we're less an "alcohol stove" and more of an "alcohol solution/system." Our stove is fine, but it's the cone that is the real trick here."
Really great stuff Rand! Thanks so much for sharing!
The Caldera Cone System is sold at a fair value, weighs only a few ounces (depending on your pot size), and will be built specifically to fit your cookpot.