On Sep 28, 11:35*am, Shaun Eli >
wrote:
> How on earth could it get that cold? *Even if the compressor ran
> continuously I doubt that the cooling unit blows air anywhere near
> freezing... And given that it's September it's really not freezing
> weather in most of the world.
>
> I'd love to hear an explanation.

The Eurocave unit takes in and exhausts condenser air inside the
house. Thus the temperature it sees is whatever temperature is kept in
the house which likely does not exceed 80 F, at least for most people
who can afford to collect and age wine.. The temperature of the air in
the wine storage area is lowered as it enters the AC, passes over the
cooling coils, and reenters the storage area again. The temperature
drop of the air passing through the AC cooling coils depends on the
BTU capacity of the AC, the input temperature of the air taken in, and
the velocity of the air stream. In fact many room ACs that take in and
exhaust outdoors air to their condenser will freeze up in very hot and
humid weather if the AC is on most of the time and the velocity of the
air through the cooling coils is too low. If the wine storage area is
well insulated so that heat loss is very low, the temperature will
lower to even well below freezing until the point at which the energy
input by the AC equals that of the heat loss by the storage unit
unless a thermostat turns off the AC when a desired lower temperature
is reached. In fact commercial AC companies have no trouble designing
a very large room at or well below freezing for storage of meat,
frozen food etc. When one goes to a temperature near or below
freezing, some method of defrosting must be used to prevent ice build
up on the cooling coils. To calculate the lowest temperature of a
storage unit or room that is possible, one would have to know the
cooling capacity of the AC unit as a function of temperature, the air
temperature for air passed over the condenser, and the heat loss of
the storage area. If the maker of the storage unit skimps on the
capacity of the AC, it may be on nearly all of the time and not be
able to reach freezing in the storage area. If the capacity of the AC
is much larger than required for the storage area, it will be on for
only short periods with a thermostat and may produce storage
temperatures that are far below freezing without thermostat control.
ACs are usually designed with a lower temperature range in mind. A
room AC might not be called on for much under 71 F. A storage room for
frozen food might need to keep the storage room at 0 F or below.