Stove system comparison

While the heat exchanger pots are more efficient you do pay quite a weight penalty for them so they only become weight effective at very specific trip durations – basically when you can avoid carrying an extra canister if using a HE pot.

I know I use just under 30g of gas per day for 2 people. This is 4 boils of 2 cups (2 litres) and maybe a little simmering so 7.5g per boil using a non HE pot. There is very little difference in the efficiency of the various models of gas stoves (assuming the same wind-shielding and use of pot lid) so your figure of 10g suggests you are running the stove a bit on the high side.

My setup has a 900ml ti pot and cosy (97g), windshield (22g) and stove (FMS116T 49g) for a total of 168g. I take a full 230g canister for 8 day trips or a 100g canister for 4 day trips (3 breakfasts and dinners). This allow a day's reserve supply.

Compared to Jetboil Sol Ti (240g) which claims to boil 12 litres on a 100g canister equivalent to a 6 day trip (with reserve supply) I am usually carrying less weight. On shorter trips (up to 4 days) I am carrying less (at the start 358g vs 430g. 5 to 6 days I am carrying more (starting weight 538g vs 430g) but my weight drops faster due to the higher gas consumption. For 7 or 8 days I carry less as the Jetboil now needs a 230g canister. Any other Jetboil model and I am way in front.

This assumes a full 230g canister weighs 365g (135g empty) and a 100g canister weighs 190g (90g empty).

"It seems that the trick is that Jetboil keeps the flame closer to the pot, smaller and contained within heat exchanger."

That's what I think may be the case

The old MSR heat exchanger did that
http://www.rei.com/product/401062/msr-xpd-heat-exchanger

as does my cheaper lighter version

It's not fins on the pot that's important, it's just keeping the exhaust gas close to the pot for longer

All, interesting discussion.

Mark, good comparison of HX vs. non-HX set ups. No disagreement here. The one possible “fly in the ointment” is wind. The Jetboil does have some innate wind resistance. I see that you are using a windscreen (22g) with your set up. May I ask what it’s made of? If you get a chance, would you post a photo or two? Always curious; always looking for good ideas.

HJ
Adventures in Stoving

Thanks, this is a great observation. In reality, most of my hikes are around 3 nights and even on a 5 day hike we had a resupply cache. So, it's important that simple stove setups may come out ahead on shorter hikes.

***

I have sort of mentioned that, but wanted to underscore this point again. Our hike at some points was more like a mountain assault, where we just had bare essentials. We'd wake up in the dark, cook while in sleeping bag get up and hike until dark. So, it was very essential to have a stable and low maintenance stove system. A simple knocking over a pot would have been really bad, since at times we were down to the last liter of water and 20 miles to the next reliable source. Thinking back I am grateful that I had Jetboil for this reason as well.

Jim – I don't have a picture right now and am off for a 7 day walk in Koscuiszko this morning. I'll be giving the Spider a workout. The wind shield is a conical design in Ti which sits on a well ventilated jam jar lid. The lid is sits on top of the valve unit and held in place by the burner head.

Mark,

Have a good walk. If you remember, I’d be curious to see a photo of your windscreen.

Hope the Spider performs well, which she should. I’m a big fan (obviously).

HJ
Adventures In Stoving

While I'm boiling water much faster, I'm not seeing an increase in fuel efficiency. I''m using a Snowpeak 700 to compare it with which is obviously titanium and ~1" more narrow.

Ian,

It’s sounds like the efficiency is showing up in the increased speed. Try dialing back the valve a bit. Adjust it to the point that you get the same boil time, and I think you’ll see that you’re using less fuel.

HJ
Adventures In Stoving

It's still pretty new to me and I need to boil some more water with it. I boiled one pint on full blast and another with the stove throttled down. I used less fuel when it was wide open but no better economy than with my ti pot. I can't base an opinion on a few boil tests but so far I'm a bit meh with the pot.

It used less fuel on high? Now, that’s odd. I wonder if you’re getting incomplete combustion due to “quenching” (where the flame hits the heat exchanger too much, disrupting the combustion). Do you have a photo of it in operation?

HJ
Adventures in Stoving

Hey Jim,

I posted a picture on this thread:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=75973

I'm going to boil five pints wide open and five more on low to make a better comparison in fuel economy later this week.

Thanks for your input. Always appreciated!

v/r

Ian