My tap water is disgusting, so I buy my water via these 5-gallon (19-liter) refillable jugs. I don’t always bring them inside right away, because they’re heavy and I’m a pussy, and so they’ll oft sit in the back of my car until I need them.
In the winter, this stresses Mrs. Homie out, who insists that they’ll freeze solid if the temperature drops below 32F/0C and stays there overnight. I know she’s wrong, but I don’t know how wrong. By my estimation, 12 hours at or just below freezing means, at most, a thin layer of ice on the surface.
But how long to freeze solid in, say, a 12-hour period? My WAG is that for a 5-gallon/19-liter jug of water to freeze solid in 12 hours, the temperature would have to be in the neighborhood of -20F (-28C) for that period of time. But I could be way off.
They used to drop water bottles off at my house and leave them on the front porch if no one was home. I didn’t keep track of the temperatures but between 18 and 24 hours, at maybe an average of 27F, they didn’t freeze. Those bottles are supposed to be able survive freezing without breaking anyway, if it did freeze you’d just have to wait a little while after you carry it inside.
Do you have room in your freezer for one of the jugs? If so, put one in there for 12 hours, then show it to her. It should still be liquid enough to use as a cool pillow while you sleep on the couch.
Would the experiment scale up? If OP put 9.5 litres into a jug so that the freeze expansion has lots of room to not burst the jug or overflow into the trunk. Leave it until it freezes, then multiply the time elapsed by 2?
Fluid dynamics is a huge factor in the cooing time.
Can anybody tell from that PDF if the power is easily more than 75 Watts or definitely less? With a quick glance I think it’s more. So I think the bottle will EASILY freeze in much less than 24 hours. but maybe someone can read that article more thoroughly and/or has other sources.
If the container is sealed, the expansion of the water as it freezes can be enough to split it open. The worst-case scenario is that the bottle freezes, splits, and then thaws and leaks out all over the car floor through the new hole in the bottle.
Since liquid water takes up about 90% of the volume of the same amount of frozen water, the solution is to fill your bottles less than 90% full just to be on the safe side.
I don’t know if the OP is filling his own bottles, that can be done at some places. The ones filled at the factory look like they have enough space for expansion if they freeze. Most bottled liquids are that way to prevent freezing in storage and shipment.