Hot water freezes quicker on glass than cold water when temperature is below zero. Worse windows to clean when below zero are conservatories with no internal heating.
No it doesn't mate.....I thaw ice off glass and frames in cold weather with hot water...when I used to use cold it wouldn't touch it....
Absolutely disagree with you!
If you pour one litre of hot water over glass that's not frozen in sub zero temperature, it will freeze up quicker than cold will .....it's a well known proven fact called mpemba effect, look it up on google. Cold water is denser, hot water evaporates quicker.
Mpemba effect: As the initially warmer water cools to the initial temperature of the initially cooler water, it may lose significant amounts of water to evaporation. The reduced mass will make it easier for the water to cool and freeze. Then the initially warmer water can freeze before the initially cooler water, but will make less ice.
I know about the Mpemba effect, but honestly, in the real world of window cleaning it doesn’t happen. Perhaps with boiling water where evaporation is more prevalent? Who knows. We only use warm/hot.
Have you tried this in practice? I presume the theory behind it must be that it occurs in a specific set of scientific circumstances that in the real world we just don’t see.
For instance…….. a conservatory that has no heating and glass is all frozen up.
Cold water user - your water adds to the ice on the windows, it’s impossible to clean without scraping everything off, and even then it’s likely to ice up as soon as you start.
Hot water user- you thaw the ice off first in a few seconds, then clean the window as normal. In my experience the residual heat you put on the glass stops the few remains droplets freezing, but even if they do freeze it’s pure water that when it thaws out it looks perfect.
If the Mpemba effect was evident in our job then hot water would be very less effective, and I’d be noticing it every winter. In reality, I don’t.
Feels like Groundhog day with these conversations but I can’t help myself.
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