Quote:
Originally Posted by trader_4
IDK on what basis you can conclude that the humidity is going
to be 100% leaving the evaporator. Not that it matters that much.
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Well, imagine the air isn't moving. If you have room temperature air, and you cool that air down to -60 deg F, then at some point during the cooling process you'll go below the dew point and moisture will precipitate out of that air. From then on, as you continue cooling the air, moisture will precipitate out of the air and the air will remain at a relative humidity of 100%.
Quote:
But he's not keeping it at freezer temps, he's keeping it at
50F. The evaporator coils will be constantly defrosting themselves.
The coils will get cold for a short time, only long enough to drop the
temp of the unit back to 50F, then turn off. They will then warm up
and melt. Its going to have a very short on duty cycle compared
to it's off time. The real problem I see there is that he may need
some way of getting rid of the condensate, as the freezer system
may not be able to handle it.
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No, the cold control in a fridge works just like the thermostat in an oven. It doesn't shut the compressor down when the set temperature is reached because then, the fridge will be spending all of it's time ABOVE that set temperature. When you set an oven to 350 deg. F, the oven bake and/or broil elements don't shut off at 350 deg. F. Typically with the old oil filled capillaries, the oven bake and broil elements will shut off at 362 deg F and go back on again at about 338 deg F so that you have a 25 degree hysterisis that gives you an AVERAGE temperature of 350 deg. F.
A fridge's cold control will do the same thing, but I'm just not sure of the temperature range. But, suffice it to say that there's a hysterisis built into cold controls to control the temperature so that the AVERAGE temperature over time is the set temperature.
The OP said it's NOT a self defrosting freezer. So, with open containers of water in that freezer, his evaporator coils are going to get caked up with frost and he's going to be spending several hours every 2nd or 3rd day defrosting the evaporator. It's going to be just like the old manual defrost fridges, only with the frost accumulating on the evaporator very much faster, which is why I'm saying the use of a freezer to provide a cool humid environment won't work. A freezer will only provide a cool dry environment.