I am looking for a 1 unit washer/dryer for my apartment, but I have a
few constraits. I live in a 1928 building, and we're only allowed a
small space without an exhaust. It would go in my second bathroom. I
would prefer not to remove the caste-iron tub and have it stacked
above it. It must be front loaded.

somthing like http://www.atrendyhome.com/eqwas.html ?

Try Sears

An exhaust of some sort is necessary as the water removed from the
clothing needs to go somewhere. Typically the apartment humidity gets
too high, resulting in mold and mildew if you run an unvented drier
several times per week.   Neil

i have the same problem ,i got a bosch condensation dryer,works
great-no exaust needed