"Abeness" <news@nada.x> wrote in message
news:VOidnRkII9T3glXcRVn-2A@rcn.net
> Philip wrote:
>> In fact, A/C systems start cycling the compressor at no less than
>> 38 degrees F. SO... when the air coming into the evaporator
>> reaches this low temperature, the compressor is cycled or shut OFF
>> if the air temperature entering the evaporator continues to drop.
>> Otherwise the evaporator would become a block of ice, which would
>> prevent any air from reaching the heater core (in nearly all
>> cases).
>
> Now THIS makes perfect sense. (I'd have to look up the temp at which
> refrigerants go liquid to confirm or deny Steve G's belief.) I'm
> almost certain that the A/C on my old 85 Pontiac would cycle at any
> temp, though. I'll check up with the Honda soon.
>
> Anyway, I doubt it would be that difficult (in the original design)
> to construct an airflow system that would shunt warmer air around
> the evap unit when the temp dropped in winter, in order to preserve the
> dehumidifying characteristics of an A/C-based system.

Thank you ('perfect sense'). Note that I said "air coming into the
evaporator." If air door is set to FRESH and the inducted air from outside
is below 38-40°F, all one need do (considering all the heat radiating off
the passenger(s), is select RECIRCULATE so that the air inducted to the
evaporator stays above 38-40°F. This will keep the A/C running. Remember
.... once the evaporator effectively become a solid block of ice, there will
be NO dehumidification.
--

- Philip