Termyn8or
Posts: 18681
Joined: 11/12/2005
Status: offline
|
No flash here, but I been through this a million times. People getting to the point of yelling about it. So I thought about it.
First of all in a regular freezer the hot water will cause the compressor to run longer and probably more overshoot the target temperature, but I know this is not the point. The point is whether this is an old Husband's tale or not. So in that case let's take a freezer to have zero "flash" range on the thermostat, possibly even a proportional system with incredible loop sensitivity, keeping the unit within .001 F or even closer. Even better two such identical units identically loaded, as well as placed, having the exact same efficiency and everything, all else is really equal.
Physics and thermodynamics tell you that convection is started when there is a temperature differential. The only way in hell this could happen is if the convection itself induces more movement in the water before it actually solidifies. In other words it is circulating faster and therefore it will circulate longer until actually frozen. This will conduct the heat away from the inner parts of the water mass more effectively once it reaches the freezing point, assuring that the parts of the mass of water are actually changing states at a closer time. To guage this effectively you need some tools. Simply looking at it does not tell you assuredly the the entire mass is frozen.
But conversely, look at it the other way. Just look at how an ice cube freezes. It freezes on the outside first of course. You can see that any day of the week if you have a freezer, icecube trays and a source of water. What I assert to be the only possible explanation of hot water freezing faster would be that it freezes more evenly. In other words the progression from the outward parts to the inward parts, when it comes to changing states is accelerated.
But it is still our perception. If we freeze cold water and find that when it is deemed to be frozen there is a 20 F difference between the surface and the center, but freezing hot water results in a lesser discrepancy, it is still subjective. That is because the laws of thermodynamics are real laws, which cannot be suspended. You still need to remove X amount of BTUs of heat to freeze the water, and no logic on this planet can argue that this would require less energy if you start with warmer water.
I just moved, but when I find my Nelkon and Parker book I will look it up. They probably did address this, but I missed it.
T
|
Which One Freezes Faster? - 
Profile
RE: Which One Freezes Faster? - 
New Messages
No New Messages
Hot Topic w/ New Messages
Hot Topic w/o New Messages
Locked w/ New Messages
Locked w/o New Messages
Post New Thread