I've been tinkering with improving the Kovea Spider's boiling efficiency using reflector plates and windscreens. Wondering if anyone found a balance between weight and improved efficiency. So far I've tried:
Parameters:
4 cups freezing water, + 16 ice cubes –> rolling boil (+/- 5sec) Test pot is a FourDog 1.8 stove, aluminum, without lid (so I can see the exact time of boil). Average fuel use of Kovea Spider was 2g/min.
Windscreen test:
Aluminum flashing windscreen with 10mm barrel spacing rigidly attached to the pot using a hose clamp shortened and riveted to the cylinder. Design was to be immune to wind and spindrift…. but turned out heavy. So heavy I think I tossed it. Nice reduction in boiling times from ~9min to 6min, tho.
Reflector test:
Aluminum flashing reflector plate. Cut in a circle and bent three edges to for a triangular base with three 'fins' angled upward. Hole cut in center which dropped over the Spider's burner plate, and it rested on the bent midsection of the legs. Reduced boiling time from ~9min to 7min 30sec even without windscreen. Could probably improve this design with the right cutout pattern – the 'wings' leave large open sections where they meet. 12g.
I figure I will boil 4 L of water per day in winter. Since it takes ~9min to boil 1L liquid water (~32F) it will take 18min for snow and ice per liter. That's 36g of fuel; 144g per day. Using a 12g reflector plate I drop that to 13min, 26g of fuel; 104g for the first day… a savings of 40g. So the weight of the reflector plate is obviously worth it. I understand, of course, that in subfreezing temps these boiling times will increase (offset slightly by use at elevation) but that only increases the need for stove efficiency. I also understand that using the lid will reduce boil times.
I'm wondering how substantial an improvement a low, wide pot will have vs the FourDog 1.8L stove (used more for campfire cooking and hanging). Also if I wrap an MSR 2L squat pot in a neoprene sleeve (ref: JetBoil companion cup)… how much would that cut down conductive heat loss? I think the consensus for third-party heat exchangers is that they don't increase fuel efficiency enough to justify their weight… but what of the Jetboil 2L pot w/ integrated heat exchanger?
