QuietStove.com

Wednesday, April 17, 2013

Canister Gas Stoves -- Recommendations and Efficiency

I got a note recently, below.  I responded individually, but there were some good questions, so I thought I'd expand just slightly and turn it into a blog post.
Hi Jim, 
It was great meeting you at the GGG at Henry Coe [State Park].  Just wanted to ask - what's your current best (good fuel efficiency, low CO emissions, low weight, etc.) sit on top canister stove, and your current favorite remote stove (the Kovea Spider or other)?  Been narrowing down stoves and cooksets and really appreciate your advice.  And for remote stove, what do you use for your windscreen, a Caldera Cone or other?

Remote Canister Stove Recommendation
The remote canister stove is easier for me to answer because I have such a clear favorite:  The Kovea Spider.  It's a very compact, durable design, and it's a design that just makes sense.  It can be run with the canister upside down for cold weather use.  I really like this stove, but, unfortunately, I don't have carbon monoxide (CO) numbers for it; that's beyond the scope of my capabilities.

The MSR WindPro is also very good, but the WindPro is not nearly as compact.  For a larger group (more than three), I might choose the WindPro since it's wider pot support span will support a little bit bigger pot.

The Kovea Spider, left.  The Kovea Supalite, right.  Both excellent stoves.

Upright Canister Stove Recommendation(s)
And as for upright canister stoves, what would I recommend?  There are an awful lot of good ones.  In terms of efficiency, it's generally more about how you use the stove (see below) than it is about the stove itself.  I happen to like the Kovea Supalite (~56g/2.0 oz depending on the version).  It's reasonably light, reasonably compact, and has good pot stability.  You can get lighter, but I think the pot stability is better on the Supalite than anything lighter that I've seen.  The absolute lightest is the FMS-300t which is 45g/1.6 oz, but it has problems with clogging at the jet.  I can't recommend it (yet) even though it has some nice innovative design features.  I've read that the Optimus Crux has high CO, so you might avoid that if you want to cook in the vestibule.  I generally am not a fan of the MSR PocketRocket even though it's very popular.  I much prefer the newer MicroRocket.  The MicroRocket is a bit more compact than the Supalite.
The MicroRocket is particularly compact -- it will fit in a 550ml mug pot with a canister of gas.

Canister Stove Efficiency (Best Practices)
As for efficiency, with canister gas stoves, both upright and remote, it's typically more about how you use the stove than it is about the stove itself -- at least with the major stove brands.  All bets are off with "no name" stoves that one can buy off of eBay for shockingly low prices.  Caveat emptor.

However, with something like a Caldera Cone with a gas stove, that's another matter.  See the special section on the Caldera Cone at the end.

So, what are those good practices that lead to efficiency?  Well, here's my list:
  • Turn it down.  High heat = inefficient.  This is the number one mistake of canister stove users -- they turn things up too high.  Low heat = efficient.
  • Pick a sheltered spot.  On top of a rock might be convenient, but it's going to be windier up there.  Go behind the rock, and set the stove on the ground.
  • Use a windscreen (yes, even on an upright type canister stove, but not a full 360 degree windscreen) -- be careful to check the canister frequently with your hand.  If it feels hot, take immediate steps to cool things down.  See Canister Stoves and Wind before you use a windscreen.
  • Use a lid.  Tighter fitting is better.  Escaping steam = escaping heat = inefficient.
  • Use a wider pot.  Tall, skinny pots wind up having flames go up the sides, wasting heat.  A wide pot catches that heat.
  • Use a heat exchanger pot.  Usually the heat exchanger weighs more than the amount of fuel you save, but if you really want efficient, a heat exchanger is the way to go.  If on a trip you prevent having to carry a second canister, a heat exchanger can actually save weight overall.
  • Use a darker colored pot (minor compared to the others)

Windscreens -- Upright Canister Stoves
Yes, use a windscreen with an upright canister stove.  Just do NOT use a full 360 degree windscreen AND be really careful.  See Canister Stoves and Wind.

Windscreens -- Remote Canister Stoves
For remote canister stoves, you can use a full 360 degree windscreen safely.  Indeed this is one of the many reasons people use a remote canister stove even though it's heavier than an upright (the other main reasons are pot stability and improved cold weather performance).  With the Kovea Spider, I have just been using a plain heavy aluminum foil (~36 gauge) windscreen from MSR.  It's their standard windscreen for their remote canister and white gas stoves.  Works great.
A Kovea Spider stove with a standard MSR windscreen.
The Kovea Spider with a Caldera Cone
But can the Kovea Spider be used with a Caldera Cone?  Now that is an interesting question.  As a matter of fact it can.  Here's a Spider with a full height Caldera Cone and an MSR Titan Kettle.
A full height Caldera Cone with a Kovea Spider inside
The stove fits inside well.  The pot sticks up about 1cm or so -- not a problem.  In terms of efficiency, I think you could do very well with this set up.  You would want to be very careful to keep the flame low.   An aluminum cone could melt if you turned the heat up high.

Of course there are different styles of Caldera Cone.  Here's a Sidewinder style cone with a 1.3L Evernew pot.  This is a titanium Ti-Tri cone.
Sidewinder Ti-Tri (titanium) Cone with an Evernew 1.3L pot with a Kovea Spider inside
 A sidewinder cone is a shorter cone which is intended to be rolled and stored inside the pot (I really like the sidewinder design).  The pot therefore does stick out more.  Still, this would be a very effective windscreen, and the design of the vents, which control air flow and channel hot exhaust up the side of the pot, would increase efficiency.

You could of course take the pot supports off the Spider to save weight, but then you'd have to figure out a way to suspend the pot at the correct height above the burner.

Thanks for the questions; I hope the answers are satisfactory,

HJ

2 comments:

  1. Jim

    Here's a preliminary method of cutting down the weight of the Spider - more refining to do - 125g with full windshield. http://bushwalk.com/forum/viewtopic.php?f=53&t=12876 I am also looking at replacing the burner head of the Spider with the burner head from the Supalite which includes the pot supports - then cut off the legs and lower the stove - it sit way too high above the ground.

    The issue with the Fire-Maple jets is the cleaning if they get blocked due to the sintered plug. They only block, as would any jet in any stove, if good stove hygiene is not practiced or or a very suspect brand of gas canister is used.

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    Replies
    1. Fascinating. I knew the legs were a lot of the weight.

      HJ

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