Keeping water bottle cold

[still me]

On Tue, 11 Sep 2007 04:01:08 GMT, "Mike Jacoubowsky"
<[email protected]> wrote:

>
>Right. I didn't figure evaporative cooling was in force, since there was no
>air passing by to aid in evaporation. So a loosely-fit plastic baggie would
>be better than a tight one, since when loose, you have "dead air" space?

The best choice would be a bottle suspended in the bag so that no part
of it actually touched the bag. That way you get dead air as an
insulator and minimal conduction and convection. It the bottle is
contacting the bag, you have an issue. The paper towel rap helps with
that.

 

[Michael Warner]

On Tue, 11 Sep 2007 23:45:25 GMT, still me wrote:

>>Right. I didn't figure evaporative cooling was in force, since there was no
>>air passing by to aid in evaporation. So a loosely-fit plastic baggie would
>>be better than a tight one, since when loose, you have "dead air" space?
>
> The best choice would be a bottle suspended in the bag so that no part
> of it actually touched the bag. That way you get dead air as an
> insulator and minimal conduction and convection. It the bottle is
> contacting the bag, you have an issue. The paper towel rap helps with
> that.

Someone I ride with who lives part-time in the US has a bottle insulating
pouch he bought there which works on the same principle - it's two
layers of soft plastic separated by a thin layer of foam. I haven't seen
them on sale here (Australia).

IWHT it'd make getting the bottle in and out of the cage difficult, but it
didn't seem to cause him a problem.

 

[Leo Lichtman]

"Bill Sornson" wrote: (clip) Making a short, humorous quip intended to
tweak one of the most partisan, hate-filled, mean-spirited morons around
(clip)
^^^^^^^^^^^^^^^^
I didn't get it until you helped me make the connection to the President.

 

[Andrew Price]

On Wed, 12 Sep 2007 09:39:28 +0930, Michael Warner
<[email protected]> wrote:

>Someone I ride with who lives part-time in the US has a bottle insulating
>pouch he bought there which works on the same principle - it's two
>layers of soft plastic separated by a thin layer of foam. I haven't seen
>them on sale here (Australia).
>
>IWHT it'd make getting the bottle in and out of the cage difficult, but it
>didn't seem to cause him a problem.

Maybe he has a larger cage - I don't know what's available in Oz, but
I have noted that there are noticeably differences in diameters of
bottles from Germany and Switzerland (narrower) and France (wider).

 

[Michael Warner]

On Wed, 12 Sep 2007 21:28:40 +0200, Andrew Price wrote:

> Maybe he has a larger cage - I don't know what's available in Oz, but
> I have noted that there are noticeably differences in diameters of
> bottles from Germany and Switzerland (narrower) and France (wider).

Good point. He'll be arriving here for summer in a couple of months
(tough life, eh?) so I'll investigate then

 

[[email protected]]

On Sep 10, 6:03 pm, Michael Press <[email protected]> wrote:
> In article
> <[email protected]>,
> "Mike Jacoubowsky" <[email protected]> wrote:
>
>
>
> > I discovered something entirely by accident that might be of use to others.
> > How to keep a frozen water bottle... frozen.
>
> > Rocket science it isn't.
>
> > When riding with my son, I carry quite a bit of extra water, in a rack-top
> > bag. What I'll often do is freeze a couple of bottles overnight, but they
> > would thaw out very quickly. But another time I had to use my camera
> > backpack, and to make sure the bottle didn't drip into the bag (Cytomax
> > wouldn't be good for camera gear), I wrapped the bottles with no more than
> > two layers of paper towels, and put them into a gallon-sized sealed baggie.
>
> > Amazingly, 7 hours later and the contents were still 80-90% frozen. Tried
> > the same experiment in the rack top bag, same thing again. Nearly totally
> > frozen bottles at the end of a long ride (yeah, sounds like I brought too
> > much stuff to drink!).
>
> > I haven't yet tried just wrapping one up and putting it into a regular
> > bottle cage, so don't know yet if that would work as well. Could be that
> > there's some insulative qualities to the bags which makes the difference
> > (even though bottles without any paper towels wrapped around them and placed
> > into a baggie thawed out very quickly). The easiest experiment might be to
> > just prepare one and leave it on the counter at home and see what happens in
> > a day.
>
> > It seems absurdly simple. Why it works is up to someone here to tell me. So
> > much for the idea you need to buy a special insulated bottle to keep things
> > cold!
>
> Three principle modes of heat transfer
>
> * Convection
> * Conduction
> * Radiation
>
> This is is in order of descending rate of heat transfer
> in a configuration that optimizes the mode. For instance
> radiation is optimized in the high desert at night where
> the heat can radiate directly into interstellar space.
> (This is also why frost can form when the air temperature
> is above the freezing point of water. The dew is coupled
> to a heat bath well below freezing: outer space.)
>
> Keeping the bottles out of the wind is the winner, as
> it takes convection out of the heat transfer business.
> Ice is an enormous heat sink.
>
> --
> Michael Press

To reduce the radiative cooling effect, you might try adding a
reflective layer. Aluminum foil or emergency blanket material.

Cut up an emergency blanket for a strip to wrap around the side and a
bottom hole cover and glue together instead / inside of the ziploc bag

 

[still me]

On Fri, 14 Sep 2007 04:23:45 -0000, "[email protected]"
<[email protected]> wrote:


>To reduce the radiative cooling effect, you might try adding a
>reflective layer. Aluminum foil or emergency blanket material.
>
>Cut up an emergency blanket for a strip to wrap around the side and a
>bottom hole cover and glue together instead / inside of the ziploc bag

There's a moderately flexible insulating product with a reflective
surface and foam on the backside, sticky applied, about 5mm thick you
could use for this. It's used to wrap heating ducts and such to
allegedly improve them. I have my doubts that it's worth it for them,
but it would work well inside a bag to create an insulated pouch. You
could even set it up back to back and get double insulation and
reflection.

You can buy a roll of aluminum tape (what pro's use instead of duct
tape on ducts) to secure the seams you need to seal.

As I recall, about $12 for a lifetime sized roll of the stuff at Home
Depot, aluminum tape is about $6 a roll (or use the ol' duct tape).