- #1
gummby8
- 2
- 0
I am currently building a water cooled vest for the hot days here in Phoenix Arizona. Some days in the summer can reach upwards of 115 degrees F, and I would like something to keep me alive if I go out to ride my Motorcycle or just work out in the backyard.
My current design is a vest with 1/4 clear vinyl tubing laced throughout that all leads back to a 2 liter water bladder filled with a 90% water 10% ethanol solution (so I don't have to worry about algae). A 12v DC pump keeps the water moving.
Inside the water bladder are removable cold packs.
My question is what would stay colder longer.
Cold packs filled with the same 90% water 10% ethanol
or
Cold packs filled with 100% ethanol
My thought is, pure ethanol's freezing temp is drastically lower than pure water, -173.2°F vs 32°F.
The average freezer temp is 0 °F.
But pure ethanol does have a lower heat exchange rate than water. Does that mean that ethanol would keep the water slightly cooler than ice for a longer period?
My current design is a vest with 1/4 clear vinyl tubing laced throughout that all leads back to a 2 liter water bladder filled with a 90% water 10% ethanol solution (so I don't have to worry about algae). A 12v DC pump keeps the water moving.
Inside the water bladder are removable cold packs.
My question is what would stay colder longer.
Cold packs filled with the same 90% water 10% ethanol
or
Cold packs filled with 100% ethanol
My thought is, pure ethanol's freezing temp is drastically lower than pure water, -173.2°F vs 32°F.
The average freezer temp is 0 °F.
But pure ethanol does have a lower heat exchange rate than water. Does that mean that ethanol would keep the water slightly cooler than ice for a longer period?