How can we chill water in a plastic bottle without a freezer or refrigerator?
I'm in the office and I have two plastic bottles of water (brought from home). I'm in the office for 3 to 4 hours and this means the bottles I brought from home will get hot (and won't be drinkable in a hot season). Now I want to make it cool so that I can drink chilled water, without access to ice with salt or a refrigerator.
The old system of keeping things cool utilized the evaporation of water, which takes its latent heat from the item you want to keep cool (milk, butter etc. normally). Either using a cloth soaked in water (and dipping into water at its base) or a coarse earthenware vessel, it worked.
It's pretty easy. Put one of your bottles in the freezer when at home and let the water turn into ice. Then wrap an old cotton t-shirt around the bottle so that it makes a thick insulating layer around it. Then fasten the cloth with a safety pin. This would prevent the ice from being melted quickly and provide you with cool water for almost a day. With a little enthusiasm you can make it so that you just have to change bottle through pulling old ones and pushing new ones into the cloth without necessarily opening the cloth.