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Gas Stoves: How Mutual Depression Temperature Tin Ane Go?

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Gas stoves (also called canister gas stoves) tin care inwards mutual frigidity weather.
Frozen lake together with snow, Sierra Nevada Mountains
UPDATE, 17 Dec 2014:  I've almost completely re-written this article.  I've tried to beak to a greater extent than close the overall procedure of planning for mutual frigidity weather condition trips.  I've also tried to beak close to a greater extent than than only the gas inwards a canister; I've added intelligence of the practicalities of mutual frigidity weather condition canister operation.  One should non rely on the gas lonely but also on one's ain planning together with techniques.

So, how cold tin I go with my gas stove?

Good question.  Do you lot desire the curt reply or the long answer?

The "Short" Answer
The curt reply is that for the typical upright canister stove (that's the variety where the burner screws straight onto the canister), about 20°F/-7°C can last used every bit a rough planning number.  For a longer answer, come across the appendix.  Understand though that the colder it gets, the to a greater extent than your stove volition care fifty-fifty if it's warmer than my planning number.  Your stove volition not work only every bit good at 20°F/-7°C every bit it volition at 75°F/24°C, at to the lowest degree non without planning together with intervention on your part. You volition involve to know the basics of mutual frigidity weather condition gas stove functioning which are:
  • Choose proficient fuel.  See What's the Best Gas for Cold Weather?
  • Start amongst a warm canister.  Keep the canister inwards your sleeping handbag amongst you lot earlier breakfast, position the canister nether your wearable earlier supper, etc.
  • Keep the canister warm. Put some insulation nether the canister (closed prison theatre mobile telephone foam industrial plant well), protect the stove from wind, together with position the canister inwards a bowl of (liquid!) water.
  • Heat the canister if needed. How tin you lot tell if you lot involve to oestrus the canister?  Poor performance.  If your flaming is insipid inwards mutual frigidity weather, you lot involve to (carefully! slowly!) oestrus the canister.  See my the basics of mutual frigidity weather condition gas stove operation.  My oil planning number for upright canister stoves is 20°F/-7°C together with inverted canisters stoves receive got roughly a twenty Fahrenheit/11 Celsius marker payoff over upright stoves, thence I utilisation 0°F/-18°C every bit the oil planning number for inverted canister stoves.

    Note that fifty-fifty amongst liquid feed gas, i soundless needs to receive got some pressure level inwards the canister to drive the process.  Therefore you lot must keep the canister "warm" relative to the exterior environment.  Placing the canister inwards H2O is a rubber way to continue the canister warm.  Water freezes at 32°F/0°C, so, every bit long every bit the H2O is liquid, your canister volition last warmer than 32°F/0°C.  Keeping the canister higher upwards 32°F/0°C should give you lot to a greater extent than than plenty canister pressure level to run your stove.

    The planning numbers I propose are guidelines for reducing risk; at that spot are no guarantees inwards the dorsum country.  The planning numbers I propose are temperatures inwards which you should be able to continue your fuel sufficiently warm to operate a canister gas stove.  Keeping the canister warm requires intervention on your part.  Note all the same that "stuff happens."  If temperatures drop, if winds alternative up, or if you lot are exhausted or injured, you lot may non last able to continue your fuel warm.  You must last prepared to handgrip these together with whatever other unexpected changes or emergencies that may occur.  These planning numbers cannot last used alone.  You must engage inwards proper planning, convey the proper equipment, together with you lot must know together with utilisation the basics of mutual frigidity weather condition canister operation.

    Finally, the colder you lot go, the harder it is to continue the gas warm inwards a canister.  If you're going out inwards actually mutual frigidity weather, inquire yourself:  "Can I actually continue the canister warm?"  In mutual frigidity weather, an abundance of caution is the best advice I tin give you.

    HJ


    Appendix – The "Long" Answer
    So, what am I basing my planning numbers on?  Well, let's beak a piddling bit, at a high level, close the chemical scientific discipline of canister gas.  If this gets also irksome or confusing or if you lot disagree or you lot only manifestly don't similar what I've written, I commend to you lot a much simpler approach inwards Cold Weather Tips for Gas Stoves.

     Now for the "long" answer:  Canisters for backpacking typically contain propane mixed amongst either isobutane or "plain" butane (n-butane).  The boiling points (vaporization points) at ocean level of each of these gases are every bit follows:
     Boiling Point n-butane    -0.5°C    31°F isobutane    -12°C    11°F propane      -42°C   -44°F

    When you lot blend the fuels together, your boiling indicate volition last somewhere inwards betwixt the boiling indicate of the diverse fuels.  Calculating the exact boiling indicate is non trivial.  Not only that, but the proportions of the fuel mix volition alter over fourth dimension amongst an upright canister stove.  Why volition the mix alter over time?  If the canister is used inwards the normal, upright position, the propane volition boil off at a faster charge per unit of measurement than either n-butane or isobutane because if its higher vapor pressure.  Since the propane is boiling off faster, at that spot volition last less together with less propane inwards the mix over time.  As the pct that is propane declines, the boiling indicate rises.

    OK, so why all this blather close boiling points?  Well, the boiling indicate is the temperature at which your fuel volition plow to vapor, i.e. alter from liquid to gas.  Canister gas stoves require gas to operate, but that's a liquid inside your canister.  Just milkshake the canister if you lot don't believe me.  That's a liquid inwards there.  The fuel within the canister is nether such high pressure level that the gas liquefies (turns into a liquid).  In social club to run a canister gas stove, that fuel has to vaporize.  In social club to vaporize, the fuel must boil.  If the fuel temperature is lower than the boiling point, it won't vaporize, together with your stove won't run.  For canister gas stoves inwards mutual frigidity weather, nosotros desire the lowest boiling indicate possible so that the fuel volition plow to gas so that nosotros tin run our stove.  We must together with so continue our canister warmer than the boiling indicate of the fuel.

    Well, OK, if the propane is burning off together with the boiling indicate is constantly changing, how the heck tin I figure out how warm I receive got to continue the canister!?  Well, toward the destination of a canister, all of your propane volition receive got burned off, together with you lot volition only receive got the fuel amongst the highest boiling indicate remaining (either isobutane or n-butane).  Therefore the boiling indicate of your fuel volition never last higher than the boiling indicate of the fuel that remains at the destination of a canister.  All nosotros receive got to gain at nowadays is continue the fuel temperature is above the boiling indicate of the worst mutual frigidity weather condition performing fuel.  Isobutane boils at 11°F/-12°C; n-butane boils at 31°F/-0.5°C.  Isobutane thence is a much improve fuel inwards mutual frigidity weather.  This is why I stress that i should avoid n-butane and only purchase fuels containing isobutane together with propane for mutual frigidity weather condition use.

    I've only described inwards the preceding paragraph how the propane burns off to a greater extent than speedily when the canister is used inwards upright mode.  If you lot read the "Alternatives for Colder Weather" section, I beak close using a stove that tin handgrip the canister inwards inverted (upside down) mode.  One of the advantages of using a canister inwards inverted way is that your fuel mixture doesn't alter much over time.  Since you're pulling liquid off the bottom instead of gas off the top, it doesn't affair which fuel boils at what charge per unit of measurement so long every bit there's plenty boiling to gain sufficient canister pressure.  Since you're non losing your propane (your best mutual frigidity weather condition fuel), your boiling indicate stays low.  Remember, you lot desire the lowest boiling indicate fuel for mutual frigidity weather.

    Now there's some other matter:  Canister pressure.  Just existence higher upwards the boiling indicate isn't necessarily enough.  If our fuel boils at 31°F/-0.5°C, together with the fuel temperature is 32°F/0°C, together with so it's non going to boil rattling vigorously, together with we're actually non going to receive got plenty pressure level to run a stove properly.  To illustrate this, think of the "chattering" lid on a pot of boiling water.  If the H2O is only barely boiling, the lid is quiet.  But if you lot plow upwards the heat, the H2O volition start boiling vigorously, producing plenty steam to literally elevator the lid for a moment.  The lifting (as the pressure level builds up) together with falling (after the pressure level is released) is what causes the dissonance of a "chattering" lid on a pot of boiling water.  In social club to run a stove, you lot desire the fuel temperature to last high plenty to gain a vigorous boil.  How high higher upwards the boiling indicate does the fuel temperature receive got to last to receive got plenty pressure level to properly run a stove?  Well, I suppose it depends on your Definition of "properly" (as good every bit some external factors similar atmospheric pressure level together with temperature), but the bottom employment is that if you lot plow on the stove together with the flaming isn't strong plenty to ready with, together with so the fuel is most probable also mutual frigidity together with you lot may receive got to warm the canister.  If you lot desire numbers, if the fuel temperature is 20°F/7°C degrees higher upwards the boiling indicate of the worst performing fuel, together with so generally you lot should receive got proficient canister pressure.  The performance of your stove, however, is the bottom employment every bit to whether or non your fuel is warm enough.  Caution:  If you lot oestrus the canister, together with performance doesn't improve, think.  Could at that spot last some other problem, for example, a blockage inwards the jet or an empty canister?  If you lot continue adding oestrus together with performance doesn't improve, there's something else going on.  Never oestrus the canister to the marker that the canister feels painfully hot.

    And there's yet some other issue:  Canisters larn colder every bit you lot operate the stove, through the procedure of evaporative cooling.  Canisters cool from within together with larn colder than their surroundings.  Take a facial expression at the below photo.
    Ice forming on the lower percentage of a canister inwards mutual frigidity but non freezing weather
    That's H2O ice forming on the sides of the canister fifty-fifty though the temperature is not below freezing.  Why?  Because every bit I utilisation the gas, evaporative cooling occurs, together with the canister gets colder than its surroundings.  So starting amongst a canister that is warm plenty inwards the start is no guarantee that the canister volition remain warm plenty throughout the fourth dimension that you lot are cooking.  This is why I propose heating the canister if needed.  Heating the canister counteracts the effects of internal canister cooling every bit good every bit cooling due to oestrus lost to the environment.  Here's some other payoff to using stoves amongst the canister inverted:  the canister doesn't cool from within to the same marker every bit a canister does when you lot utilisation it upright.  Thus, at that spot are 2 advantages to using the canister upside downward (if your stove volition back upwards it!):
    1.  Your propane won't last leaving the mix.
    2.  Your canister won't larn every bit cold.
    More propane + warmer canister = improve pressure.  Inverted canister stoves are definitely superior for mutual frigidity weather.

    Now, some other complication, but this i by together with large industrial plant inwards our favor:  As you lot ascend, the higher you lot go, the lower the atmospheric pressure.  As the atmospheric pressure level drops, so does the boiling indicate of your fuel.  Generally, the driblet is about 1.8 degrees Fahrenheit for every chiliad feet inwards elevation gained.  In metric units, that's about 1.0 degrees Celsius colder for every 300 meters inwards elevation gained.  Note the utilisation of the intelligence "about."  The actual values are slightly higher, specially higher upwards 10,000'/3000 m, but I'm going to last conservative here.  I'll state to a greater extent than close why inwards a moment.  Take a facial expression at the below chart.
    A nautical chart showing:
    The human relationship between boiling point and elevation for isobutane, navy bluish line, 
    Temperature vs. elevation for an internal canister pressure level of v psi approximate (psig) for isobutane, ruby-red line.
    Temperature vs. elevation for an internal canister pressure level of 10 psi approximate (psig) for isobutane, gilt line.
    The human relationship betwixt the freezing indicate of H2O together with elevation, dark-green line.
    Values are illustrative non exact.
    The navy bluish employment shows how the boiling indicate gets lower every bit elevation increases.  Now, of course of report it's atmospheric pressure level that's the existent issue, but since atmospheric pressure level declines relative to elevation at a fairly steady charge per unit of measurement over the interval shown here, I demo elevation.  In reality atmospheric pressure level varies non only amongst elevation but also amongst conditions, together with the alter relative to elevation is non actually linear (but it's close).  The nautical chart is a simplification of what's actually going on.  But shout out upwards that we're only later a oil planning number, a planning number that volition last incorporated into our overall trip planning process, non a number that volition override all else, so this nautical chart is sufficient for our purposes.

    OK, at nowadays why gain I only utilisation 1.8 degrees Fahrenheit per one thousand feet inwards elevation gain (about 1.0 C per 300 m) fifty-fifty though the actual alter inwards boiling indicate is (slightly) greater?  Well, let's facial expression at the ruby-red together with gilt lines on the higher upwards chart.  The ruby-red together with gilt lines illustrate what we're actually after:  Canister pressure. Notice that the ruby-red together with gilt lines are not parallel to the navy bluish line.  As it happens, the pressure level within a canister is lower inwards mutual frigidity fifty-fifty if we're the same number of degrees higher upwards the boiling point.   In colder temperatures, the fuel temperature must last higher higher upwards the boiling indicate to gain the same internal canister pressure.  Notice how the ruby-red lines together with gilt lines larn progressively further away from the navy bluish line.  The ruby-red together with gilt lines correspond a constant pressure level (5 psig together with 10 psig, respectively).  In social club to maintain a constant pressure, the ruby-red together with gilt lines larn progressively further away (more oestrus required) from the navy bluish employment every bit temperatures larn colder.   Note that these lines are non exact; inwards fact I've exaggerated them slightly for illustrative purposes. Also, the actual functions are non linear inwards progression (but they're close).  We're non planning a Mars mission here.  We only involve a oil planning number.  Approximating the true, non-linear progression amongst a linear i volition larn us inwards the ballpark.
    An MSR Reactor operating at over 23,000 feet/7000 meters elevation on Muztagh Ata (24636'/7509m) inwards far western China. Overnight lows approached -40°F (which is also -40°C; the scales are equal at -40°). One soul died on the mount during this expedition.  It was cold.  Note that the canister is labeled "Isobutane" on the side.
    Photo credit: Reuben Brimfield
    Another note:  You can't out climb depression canister pressure.  Some people receive got jumped to the determination that I'm proverb "just continue climbing to the elevation where the boiling indicate is so depression that your stove volition start working."  Uh, no.  Temperatures autumn faster than boiling points.  In other words, every bit you lot climb, it's going to larn colder faster than the elevation alter volition improve your stove's performance.  The proper thing to gain is to larn a proficient agreement of the temperatures you'll last facing on a given outing together with last prepared for them.  Don't assay to climb to improve your stove's performance.

    Now, facial expression at the dark-green line.  This represents the freezing indicate of water.  Note that the employment is flat.  The freezing indicate of H2O does non vary amongst elevation the way that the boiling indicate of our fuel does.  Any liquid H2O volition by together with large last warmer than the temperature that the dark-green employment represents.  Yes, the presence of sure enough minerals tin alter the freezing indicate of water, but for the purposes of our oil planning number, nosotros volition assume that whatever H2O that is liquid volition last warmer than the dark-green line.  Note that the dark-green employment is almost e'er higher upwards the gilt line.  In other words, if nosotros position a canister inwards water, you lot should receive got proficient canister pressure, so long every bit the H2O remains liquid.  I'm assuming hither that you lot followed the other basics of mutual frigidity weather condition canister functioning every bit well.  This is the beauty of using H2O every bit a method of heating the canister.  By the mere fact that the H2O is liquid, nosotros by together with large volition receive got plenty pressure level amongst which to cook.  However, if you're non getting the performance you lot need, you lot should last prepared to receive got action.  One activity mightiness last to receive got some H2O out of the pot that you're heating together with position it into the bowl that the canister sits in.  Don't larn it also hot!  If you lot add together only a demeanor on of warmer H2O (slowly!) to the H2O that is already inwards the bowl, you lot volition convey the H2O temperature upwards a chip together with increment your stove's performance.  There are other ways to oestrus the canister, but liquid H2O is pretty rubber so long every bit the canister never feels hot to the indicate of hurting to the (unfrozen) bare hand.

    Of course of report you lot tin modify the stove to divert oestrus to the canister from the flaming straight instead of using water, but at that spot are risks inwards doing so. Be very careful.  Overheated canisters tin together with gain explode.  Influenza A virus subtype H5N1 canister explosion is a potentially life threatening event.  ALWAYS  monitor the canister temperature with your (unfrozen) hand.  If the canister feels hot to the touch, turn it downward immediately. 

    Now you lot may last thinking, "if I tin oestrus the canister, what's upwards amongst these planning numbers you lot continue talking about?  Shouldn't I last able to larn every bit mutual frigidity every bit I desire so long every bit I continue the canister warm?"   Well, yeah you lot can.  My planning numbers are an elbow grease to last conservative together with thereby trim down risk (reduce, non eliminate).  The colder it gets, the harder it is to continue the canister warm.  If you're going out inwards actually mutual frigidity weather condition amongst a gas stove, think.  Can you lot actually continue your canister warm inwards those temperatures?  What happens if the temperature is colder than you lot expected?  Can you lot compensate?  In actually mutual frigidity weather, your life may depend on your stove functioning.  Take no curt cuts.

    Summary:
    1.  If you lot utilisation a canister correct side up, the best mutual frigidity weather condition fuel, propane, boils off at a faster rate, so you must be able to rely on the other components of your fuel.  Therefore guide isobutane and avoid n-butane.
    2.  If you lot utilisation a canister upside downward (inverted), the propane stays inwards the mix together with your fuel has improve mutual frigidity weather condition performance.  Most stoves cannot handgrip inverted operation.  Do your homework earlier trying this.
    3.  If used upright, canisters experience meaning cooling from within.  Therefore, it is the fuel temperature which matters, non the ambient temperature.  Your fuel temperature volition last unremarkably last colder than the surroundings later operating the stove for a while.
    4.  If you lot utilisation a canister upside down, the canister volition non experience cooling (well, at to the lowest degree non to the marker that it does inwards upright operation).
    5.  In social club to receive got plenty pressure level to properly operate a stove, your fuel temperature must last warmer than the vaporization indicate (boiling point) of the fuel.  Generally, close 20°F/11°C degrees higher upwards the vaporization indicate volition give you lot proficient operating pressure, but the actual performance of the stove is the bottom line.  Poor performance in all likelihood way that your fuel needs to a greater extent than heat.  Therefore you lot must last able to oestrus the canister.  Water is typically a rubber way to oestrus the canister.
    6.  NEVER oestrus a canister to the marker that it is painfully hot to the demeanor on of an (unfrozen) bare hand.
    7.  The higher you lot go, the colder the weather condition your gas stove volition operate in, but the colder it gets, the harder it is to continue the canister warm, irrespective of elevation.  As you lot climb, temperatures autumn faster than the performance of your stove increases.  You cannot out climb cold.
    8.  If you lot oestrus the canister, you lot are non every bit constrained yesteryear the ambient temperature.  However mutual sense soundless applies here.  Can you lot realistically continue the canister warm plenty inwards the temperatures expected?  What happens if the weather condition is colder than expected? What happens if a tempest moves in?
    9.  You must know together with utilisation the basics of mutual frigidity weather condition canister functioning (select proficient fuel, start amongst a warm canister, continue the canister warm, together with oestrus the canister if needed). You must also last prepared for emergencies together with the unexpected.



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