Youth Inside

JF asked:

I just moved into an apartment that is approx 900sq ft. The wall air-cond. is in the living room, which is approx. 400 sq ft. The air conditioner is old as the hills. Here’s the prob: my air conditioner has not been cooling the room enough. The air that comes out is hardly cold, even at the highest setting.Just today it started blowing out a ‘fog’ or condensation that had an odd smell. I was worried about freeon leaking and turned it off because I have a dog. I have had the coils cleaned and typically run it at 4, which is just below the halfway point. There has been condensation where the coils are on the inside of the air cond.
My questions are this: could the air cond. be broken, why was an odd-smelling white puff cloud of air coming out of it (could it be leaking freeon) and what can I do to fix it??
Thanks for any help with this!!