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Can one cool air with a bicycle pump? Answered

Here is the thing.

I'm going on a 5 day trip and I'm taking a cool box with me.
A cool box will only stay cold for half a day with ice in it.
Compressed gas becomes cold when it expands, but buying cans of whatever gas and releasing them in the box is wasteful and expensive.

Air out of the bicycle pump is kind of cold, but not near cold enough.
How can I decrease the temperature coming out of the nozzle ?

Or does someone have a better idea on how to turn muscle power into cool drinks.

Discussions

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bwrussell

3 years ago

Air out of a bike pump is probably ever so slightly warmer once settled due to friction. The reason it feels cool coming out is due to it convecting heat away from your skin more efficiently than the still air around it.

Your best bet is a 3 day cooler with dry ice or a 5-7 day cooler with regular ice. Also ice is cheap and readily available at most every gas station and grocery store so even upgrading a 24 or 48 hour cooler is probably fine.

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DaanV1bwrussell

Answer 3 years ago

I will probably do this, it is cheap.

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seandogue

3 years ago

There are pneumatic chillers, which use a side-effect of the venturi principle to chill the container thru which the air flows. However, the amount of air delivered by a bike pump will almost "for sure" won't be sufficient as these coolers require relatively stable and high air pressure/flowrates to do their job.

I'm with those who suggest freezing drinks (and for that matter, meats and anything else than can handle being frozen for short term (cheese for instance) . Also, pack the cooler as much as possible, and make sure to apply ice *over the items and sacrifice a towel to cover all that prior to closing the container. The towel presents a "first tier" insulator when the cooler is opened. It's not going to do *a lot, but it will prevent some heat entry into the container.

four days in the hot summer is a long time to go without refreshing the ice. You may have to settle for less cold food/drink than you desire. From my own experience, fruits should be left out of the equation. Grapes will stay fresh enough for four days as will most others without refrigeration. The more room you leave for frozen objects and things that really do need refrigeration, the better.

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icengseandogue

Answer 3 years ago

+1

Click the pic to see the entire image of the magic vortex-tube..

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DaanV1iceng

Answer 3 years ago

Woah, woah.
Thanks, I'll look in to it for sure.

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iceng

3 years ago

Dry-ice in a very well insulated cooler gives you 3 to 4 days.

Don't cool grapes the CO2 makes them taste weird.

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Quadrifoglioiceng

Answer 3 years ago

+1 on the dry ice and a cooler upgrade. We always switched to dry ice for longer trips. Wear gloves when handling dry ice, it is much colder then regular ice. Even my cheap cooler, inside the car, in the summer, parked for several hours, steering wheel so hot you can’t touch it, still has partially frozen freezer packs at the end of the day.

Also, most "canned air" isn't. It is one of the newer forms of "Freon" refrigerants (difluoroethane; tetrafluoroethane, or tetrafluoropropene).

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KitemanQuadrifoglio

Answer 3 years ago

+1

Leaving the cool box in the shade, and a breeze, increases the cool-time as well.

Also, if you're camping near water (especially deep or running water), why not put all your drinks in a net bag, with a rock in the bag and a rope tied to the handles, then chuck the bag in the water? Pull it up to grab a drink, leave in submerged to cool.

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Downunder35m

3 years ago

Evaporative cooling is always good were you have it hot and dry enough.
Just needs water and a container that allows moisture to soak into it - like the old and cheap flower pot with sand and a beer can in it.
A simple towel arounda bottle works well too, just never place anything to cool with water in the direct sunlight.

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rickharris

3 years ago

Yes and No.

Compressing any gas and releasing the pressure will cool the stream of gas. This is how a fridge works BUT not with air or a bike pump.

You might look at a peltier module.

https://www.google.co.uk/#q=peltier+module

needs electricity.

You might get better results by wrapping the drinks in wet newspaper really chill better still if possible freeze then put in cooler and improve the insulation. In Victorian times ice collected in the winter was kept all year by insulating with straw.