Typical backpacking type gas canisters contain a blend of three gasses: butane, isobutane, and propane.
Each of these fuels vaporize at a different temperature: butane at 31F (-0.5C), isobutane at 11F (-11.7C), and propane at -44F (-42.1C). If your stove uses its fuel as a gas (i.e. a vapor), the fuel has to vaporize before it reaches the burner. If the outside temperature is lower than the vaporization point (boiling point) of your fuel, your fuel won't vaporize (it'll stay liquid), and your stove ceases to function. You can shake your canister and hear fuel sloshing around, but your stove is, quite literally, out of gas.
As the temperature declines and you pass each one of those vaporization points of the constituent fuels in your canister, you lose one of the components of your pressure. Also, because propane has the lowest vaporization point, it has the highest partial pressure and burns off faster than the rest. In other words, in cold weather your best fuel gets used first, and only your lower performing fuels are left toward the end. As the fuel vaporizes as you use your stove, you get evaporative cooling inside the canister, and, the canister gets colder. All these things contribute to "canister fade," increasingly weak performance as the canister approaches empty.
In cold weather (below 32F/0C), you've got a few choices:
1. Keep the canister warm, but you'll still have canister fade toward the end, and in really cold weather, keeping the canister warm is either difficult or dangerous (depending on the technique employed).
2. Switch to a liquid feed gas stove. You're still using the same three fuels (butane, isobutane, and propane), but they're fed in as a liquid, and the burner is doing the vaporization, so the outside temperature isn't as big of a deal. See my posts on the Coleman Xtreme and MSR WindPro for examples of liquid feed gas stoves.
3. Go with liquid fuel (white gasoline or kerosene).
Here are Hikin' Jim's general temperature range recommendations:
40+ F Regular Gas, Liquid Feed Gas, or Liquid Fuel will all work well.
30F - 40F Regular Gas, Liquid Feed Gas, or Liquid Fuel will all still work, but you're going to start to notice degraded performance on gas.
20F - 30F Regular Gas, Liquid Feed Gas, or Liquid Fuel will all still work, but you're going to notice degraded performance and you're going to have to use tricks on gas with many gas brands toward the low end of the temperature range.
10F - 20F You're getting below where regular gas stoves operate. If you're headed out in this kind of weather, do your self a favor and upgrade to a different type of stove. Yeah, if you fiddle with it enough, you can get your regular gas stove to work, but basic tricks don't work well down this low, and more advanced tricks can be dangerous. Dangerous as in severe injury or death.
0F - 10F This is simply below the operational range of ordinary gas stoves. This is where liquid feed or liquid fueled stoves rule the day.
-10F - 0F No way in heck on regular gas stoves. Even liquid feed gas stoves can have trouble as you approach -10F. Specialized liquid feed gas stoves like the Coleman Xtreme will handle the cold better.
< -10F Liquid fueled stoves only.
OK, so there you have it. These are "rules of thumb" and are general guidelines only. No guidelines can cover all circumstances and conditions.
All of the above are ballpark numbers at best. So much depends on other things like wind, elevation, how you use the stove, what tricks you employ, how full is your canister, which brand of gas you're using, how sheltered a spot you're in, are you cooking in a tent or out in the open, etc.
HJ
Related articles and posts:
Each of these fuels vaporize at a different temperature: butane at 31F (-0.5C), isobutane at 11F (-11.7C), and propane at -44F (-42.1C). If your stove uses its fuel as a gas (i.e. a vapor), the fuel has to vaporize before it reaches the burner. If the outside temperature is lower than the vaporization point (boiling point) of your fuel, your fuel won't vaporize (it'll stay liquid), and your stove ceases to function. You can shake your canister and hear fuel sloshing around, but your stove is, quite literally, out of gas.
As the temperature declines and you pass each one of those vaporization points of the constituent fuels in your canister, you lose one of the components of your pressure. Also, because propane has the lowest vaporization point, it has the highest partial pressure and burns off faster than the rest. In other words, in cold weather your best fuel gets used first, and only your lower performing fuels are left toward the end. As the fuel vaporizes as you use your stove, you get evaporative cooling inside the canister, and, the canister gets colder. All these things contribute to "canister fade," increasingly weak performance as the canister approaches empty.
In cold weather (below 32F/0C), you've got a few choices:
1. Keep the canister warm, but you'll still have canister fade toward the end, and in really cold weather, keeping the canister warm is either difficult or dangerous (depending on the technique employed).
2. Switch to a liquid feed gas stove. You're still using the same three fuels (butane, isobutane, and propane), but they're fed in as a liquid, and the burner is doing the vaporization, so the outside temperature isn't as big of a deal. See my posts on the Coleman Xtreme and MSR WindPro for examples of liquid feed gas stoves.
3. Go with liquid fuel (white gasoline or kerosene).
Here are Hikin' Jim's general temperature range recommendations:
40+ F Regular Gas, Liquid Feed Gas, or Liquid Fuel will all work well.
30F - 40F Regular Gas, Liquid Feed Gas, or Liquid Fuel will all still work, but you're going to start to notice degraded performance on gas.
20F - 30F Regular Gas, Liquid Feed Gas, or Liquid Fuel will all still work, but you're going to notice degraded performance and you're going to have to use tricks on gas with many gas brands toward the low end of the temperature range.
10F - 20F You're getting below where regular gas stoves operate. If you're headed out in this kind of weather, do your self a favor and upgrade to a different type of stove. Yeah, if you fiddle with it enough, you can get your regular gas stove to work, but basic tricks don't work well down this low, and more advanced tricks can be dangerous. Dangerous as in severe injury or death.
0F - 10F This is simply below the operational range of ordinary gas stoves. This is where liquid feed or liquid fueled stoves rule the day.
-10F - 0F No way in heck on regular gas stoves. Even liquid feed gas stoves can have trouble as you approach -10F. Specialized liquid feed gas stoves like the Coleman Xtreme will handle the cold better.
< -10F Liquid fueled stoves only.
OK, so there you have it. These are "rules of thumb" and are general guidelines only. No guidelines can cover all circumstances and conditions.
All of the above are ballpark numbers at best. So much depends on other things like wind, elevation, how you use the stove, what tricks you employ, how full is your canister, which brand of gas you're using, how sheltered a spot you're in, are you cooking in a tent or out in the open, etc.
HJ
Related articles and posts:
- What's the Best Gas for Cold Weather?
- How Cold Can I Run My Gas Stove?
- Gas Blends and Cold Weather Performance. (Why not just use propane?)
- Stoves For Cold Weather I (Upright canister stoves) -- Seattle Backpacker's Magazine
- Stoves for Cold Weather II (Inverted canister stoves) -- Seattle Backpacker's Magazine
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