The only way to dehumidify and not cool and not heat is to add reheat
to a standard ac unit. works good but very expensive to operate.
Normal ac does 80 percent cooling, 20 percent moisture removal.
Thermastor makes high efficiency dehumidifiers, but they are not cheap
and still add some heat back into room. Some models include a pump to
get rid of condensate. What you want would have to be custom made,
very expensive. Thermastor is 1-800-533-7533. Great product, they
make ducted models also. The only thing I have ever seen like what you
want is an indoor swimming pool dehumidifier. has built in condensor
for hot gas reheat plus outside condensor coil. It can switch between
dehumidifier and ac modes. Commercial units. Try Dectron. Wait till
you see the price on THAT!

Stretch