Evaporative Heat Loss in Upright Canister Stoves (Part 1: Measuring the Temperature Drop of Evaporative Cooling)

[Jerry Adams]

Companion forum thread to: Evaporative Heat Loss in Upright Canister Stoves (Part 1: Measuring the Temperature Drop of Evaporative Cooling)

Evaporative heat loss in upright canister stoves extends boiling times and changes fuel mixture composition. Here’s how to combat it.

[Douglas Frick]

My strategy for cold weather is to place the fuel canister in a plastic peanut butter jar lid, and add some water. The fuel canister will run until empty, even at -20*F (-30*C).

[Nick Gatel]

Thanks, Jerry. You made it easy to understand how canister stove fuel works.

[Mario Caceres]

Thank you Jerry for this interesting article and tests.  As Douglas, I found that keeping the canister inside a bowl of water works well to operate stove in cold conditions.  I normally use one of those collapsible bowls but probably the peanut butter lid is lighter.

Here a picture of my set up.

[Mario Caceres]

As long as the water in the bowl remains liquid you know the canister is above freezing (32*) so no issues with performance of the stove.  As you have noticed in your tests, as you run the stove the canister drops in temperature so periodically I need to add a bit of the boiling water into the bowl to keep the water above freezing.

[Jerry Adams]

I talk about that in part 2.  Yeah, good points

By the way, none of this is all that unique.  Lots of threads about this.  I don’t claim to be more expert than others : )

But, I haven’t seen actual measurements of how many degrees drop there is, how it varies with amount of fuel left, and a few other points.  And since I don’t do this for work any more, I have to continue doing engineering stuff to entertain myself.  I think some of this will be interesting to BPL people.

[Jerry Adams]

and Roger added a lot to these 4 parts, and I stole ideas from Bob, Gary, https://adventuresinstoving.blogspot.com/,…

[Ben C]

Good work, Jerry.  And I rarely even use a canister stove.

[James Marco]

Thanks, Jerry!

[WILLIAM BEHRENDT]

Why use an up right canister when one can simply invert the canister and receive a constant pressure throughout the burn.

[Roger Caffin]

If you are using a BRS-3000T (or any other upright stove) stove, inverting the canister may be considered hazardous to your health.
After all, the title of the article does say ‘in UPRIGHT canister stoves’.

Cheers

[Jerry Adams]

That’s a good solution.  Most stoves don’t allow inversion.  Stoves that do tend to weigh more (except Roger’s is pretty close to the lightest).  When inverted, stuff from the canister can get out and clog the valve.  All solutions have pros and cons.

[Paul bayne]

Has everyone seen one of these valves: https://www.amazon.com/gp/product/B00U2EE6M2/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

It allows you to get those unused bits of fuel from partial cans into another mostly full can. Or to fill the small cans from bigger ones with the exact amount you need. I think I learned about these on one of the BPL forums. I have had great success. Works in the field on really long trips (although I still use liquid for unsupported trips upwards of 7 days). There may be some issues with what type gas is left in an almost empty can so it can throw off the ideal ratios from something like a new MSR can. Never had an issue in mild to hot conditions.

This is getting really out there, but G-works also has adapters to run Lindal valve devices directly off of propane bottles, including the big grill size cans. These are some limited applications for most folks, but for program use and some other wacky scenario’s it is pretty handy to have multi-fuel capabilities.

And finally, you can combine the two adapters and fill standard lindal cans with propane. Again, limited applications and a huge list of “this voids warrranties and is dangerous if you do it wrong” type stuff.

Paul

[Jerry Adams]

That’s in part 3 : )

Which Bob clued me into on a previous thread.  I added a little information to what Bob said.

Yeah, I have used that successfully, great idea

As mentioned on a previous thread and in part 3, if you put straight propane into a canister, the pressure is higher.  It can cause the bottom to push out, if you’re lucky, or burst if you’re less lucky.  Some people do this as long as you keep the canister below room temperature or something.

[Alex H]

Nice work Jerry, I look forward to the rest of the series.

[Bob Moulder]

Paul, if you combine your adapter with this adapter you can also use cheap butane cartridges (available at most Asian markets) to refill your canisters. Works just fine in your “mild to hot” conditions and the BTUs are about the same as Isobutane and Propane. But it’s nice to have the flexibility to use other fuels for car camping, group situations etc.

 

[Jerry Adams]

and that’s the fuel I used (based on Bob’s recommendation) for my testing – boiling point 20 F – when you consider evaporative cooling you start getting into trouble below freezing, but then you have to use the Moulder strip or whatever…

I got 4 cans, 8 ounces each, for $5

[Gary Dunckel]

Jerry, I liked your article. You summarized the cooling of the canister nicely, you correlated it with the amount of fuel remaining, and you did it for both sizes of canisters. Well done.

[Jerry Adams]

thanks : ) I believe there’s an article coming that you did that I look forward to

[Sam Farrington]

Hi Jerry,
Thanks for your research and reporting about the canister. Look forward to the next installments.

I learned the hard way that altitude may also affect the burn time of a canister.
For a number of years, I used Coleman cheap “butane-propane mix” canisters in Colorado, camping at 9-12,000 feet in July and August, and found that the canisters would last 6 days (5 nights) and still have some gas left. The meal routines for stove use were always the same, requiring approximately the same boiling and simmering times, and the canisters were weighed before the trips to see that they were full.

Then I commenced a 6 day loop trip in May in the Nash Stream-Phillips Brook area in northern NH, camping at 1-3000 feet, with the same routines and full canister. It was the first time in the Northeastern US that I had brought only one canister, based on the Colorado experiences. The canister ran out on the 5th morning (4 nights), possibly because the boiling and simmering times required for the same food and drink increased. The air temperature was about the same for both the CO and NH trips. Had planned to camp the 5th night on an open mountain ridge with no firewood, but it had been raining for several days, so the last day was a long one.

[Roger Caffin]

Hi Sam

You do not mention the size of the canister you took to Nash Stream. I assume it was a 110 g one if it ran out after 4 nights? Even so, that’s a lot of gas used for one person for 4 nights. Or were you cooking for 2?

Cheers

[Jerry Adams]

The boiling temperature of water is less at higher altitude, so it requires less fuel to boil a given amount of water – you’re not heating the water to as high a temperature.  Maybe that’s why you use less fuel at higher elevations?

[Sam Farrington]

Hi Roger,
Re “You do not mention the size of the canister you took to Nash Stream. I assume it was a 110 g one if it ran out after 4 nights? Even so, that’s a lot of gas used for one person for 4 nights. Or were you cooking for 2?”

Myself and two dogs, around 30# each. Water was also boiled in the mornings.
These were Coleman 220g canisters. They weigh around 13 oz. when full, and fit nicely into a 900 ml ‘pasta pot’ if not too old and rusty.
The morning routine was to bring 750 ml of water to a boil, for hot water for a premix of instant coffee, instant breakfast and milk powder in a smaller pot. (warning: the powder will clump unless poured into and mixed with the water a little at a time, OR the powder can be mixed cold, then poured into the separate container and drunk cold or reheated – depends on the weather). The remainder of the boiled 750 ml was used for black tea, to moisten the 2 dogs’ kibble, and for clean-up.
The evening routine began the same way, but one cup of the hot water was poured into the smaller pot with a premix of some form of pasta and freeze dried meat, and then covered and simmered for 15-20 minutes, stirring regularly. When judged ready, a premix of seasonings was stirred into the cooked meat and pasta. The remainder of the 750 ml of hot water was used for herbal tea, moistening the dogs’ kibble, and for clean up.
The premixes for each meal were all packaged in separate polyethylene bags sealed and trimmed with a U-Line sealer.
There was usually enough boiled water in the larger 750 ml pot to complete the meal. Often, the 750 ml was just scooped from a nearby stream with the 900 ml ‘pasta pot,’ so the figure is not exact.
Same pots, same dogs. Pots were both Ti.

[Roger Caffin]

Hi Sam

Ah – 2 dogs. So about 2 people, and about 55 g/night. Even so, that’s a lot of gas used. I use 30 g/day for the two of us.
Um – OK, that’s in our summer with a cold breakfast. Winter might see us using closer to 50 g/day, what with warm milk for breakfast and so on. Understood.

Cheers

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