3 ms·

Water is a pretty amazing heat carrier. I did a bit of poking around for a project idea and couldn't really find anything with a higher heat capacity, at least

Water is a pretty amazing heat carrier. I did a bit of poking around for a project idea and couldn't really find anything with a higher heat capacity, at least for things that don't undergo a phase change. I wonder if there's a semi-low-tech way of taking advantage of a phase change for extra capacity in something like a hot water bottle.

smeyer 5y ago
People take advantage of phase changes as a way to store thermal capacity frequently. Here[0] is one designed to keep your coffee hot by using a material with a phase change temperature similar to a temperature folks like to drink coffee. [0] https://www.joulies.com/ https://www.joulies.com/
- calvinmorrison 5y ago
  Tangentially related are "Boveda" packets which are the opposite of silica packets for keeping food dry, they keep your box perfectly humidified. For optimal cigar storage or consumption - the humidity is a huge factor. Boveda packs are sold by target humidity and are pretty awesome (protip: you can reuse them by soaking them in distilled water for a while after they dry up0
falcolas 5y ago
People were recommending wax elsewhere, since its phase change is above 20°C.
masklinn 5y ago
> Water is a pretty amazing heat carrier. I did a bit of poking around for a project idea and couldn't really find anything with a higher heat capacity, at least for things that don't undergo a phase change. Pretty much the only thing better would be ammonia, and it's not necessarily as good for water bottles: it has a higher mass heat capacity, but a lower volume heat capacity. And of course you're dealing with a large volume of ammonia, which is not exactly innocuous. > I wonder if there's a semi-low-tech way of taking advantage of a phase change for extra capacity in something like a hot water bottle. There are reusable handwarmers which do that, you heat them to liquid, then phase-change them to solid. The advantage is mostly that you can trigger the release though, their heat capacity is not amazing.

smeyer 5y ago

People take advantage of phase changes as a way to store thermal capacity frequently. Here[0] is one designed to keep your coffee hot by using a material with a phase change temperature similar to a temperature folks like to drink coffee. [0] https://www.joulies.com/ https://www.joulies.com/

calvinmorrison 5y ago
Tangentially related are "Boveda" packets which are the opposite of silica packets for keeping food dry, they keep your box perfectly humidified. For optimal cigar storage or consumption - the humidity is a huge factor. Boveda packs are sold by target humidity and are pretty awesome (protip: you can reuse them by soaking them in distilled water for a while after they dry up0

falcolas 5y ago

People were recommending wax elsewhere, since its phase change is above 20°C.

masklinn 5y ago

> Water is a pretty amazing heat carrier. I did a bit of poking around for a project idea and couldn't really find anything with a higher heat capacity, at least for things that don't undergo a phase change. Pretty much the only thing better would be ammonia, and it's not necessarily as good for water bottles: it has a higher mass heat capacity, but a lower volume heat capacity. And of course you're dealing with a large volume of ammonia, which is not exactly innocuous. > I wonder if there's a semi-low-tech way of taking advantage of a phase change for extra capacity in something like a hot water bottle. There are reusable handwarmers which do that, you heat them to liquid, then phase-change them to solid. The advantage is mostly that you can trigger the release though, their heat capacity is not amazing.