Andy Hall wrote:

For the heating case, the heat is moved from outside to inside.

Ah ha... I see. the electricity is being used purely to extract heat
from one side, shift it to the other then release it.

More efficient than generating the heat directly.

Is it possible for a aircon unit to remove moisture from the air while
pumping the heat back into the room?

Just that we have an upsidedown house with the bedrooms/bathroom
partially underground so virtually no way of getting any through
ventilation. and the steam from the shower doesn't vent very well from
the bathroom as the only window is at ground level and the extractor fan
struggles to remove moist air as the bathroom is 4m x 3m.

Being underground we have survived the last 2 winters without any form
of heating as temp never dropped below about 12 degrees.
Also never goes much above 16 degrees on the hottest days, but shower
humididty is a pain.

I wonder if there is such a thing as a wall mounted de-humidifier for
such situations.

Cheers
Pete
--
http://www.gymratz.co.uk
commercial gym equipment as supplied to London-Irish & Harleqins