On Sat, 26 Aug 2006 16:43:56 -0400, "Percival P. Cassidy"
wrote:

When we lived in Taiwan almost twenty years ago we had Hitachi
computer-controlled window/hole-in-the-wall air conditioners with a
"dehumidfy" mode. In this mode they would run for a while then stop,
then repeat the cycle, irrespective of the temperature. I don't recall
what the on/off ratio was, and I don't think it was adjustable. Would it
not be possible to cycle a typical central air system in the same way to
reduce the humidity without necessarily reducing the temperature by much?

These also had a "night-time" mode, in which after 4 hours they would
raise the temperature by half a degree (Celsius) every half hour. The
idea was that one would not keep waking up because of being too cold.
Have North American A/C systems ever had such a mode?

Perce

If the condensing coils are outside, then heat will be removed
whenever the compressor is "ON", the rate-of-removal depending upon
the size of the system in tons or BTU's and, to a lesser extent, upon
the outside temperature.

Most residential A/C's are strictly fixed sized units that operate
either in the ON or OFF mode from the sensing thermostat, hence the
requirement for proper sizing to the load. An oversize unit may
bring down the temperature too fast in relation to its dehumidifying
functions. Some of the newer units with variable speed compressors
can counteract this.

Recall that a dehumidifier is just an A/C with its condenser and
evaporator coils exposed to the ambient air. The net heating/cooling
effect is zero, except for the heat added to the environment by the
electrical and mechanical resistance of the electric motors in the
system.

Beachcomber