why does my ac get humid? how to fix it?

[rb25crazy]

hey guys

i have a 97 240sx... and my ac has this musty smell sometimes when i'm sitting around and not moving past 30mph or so.

it also gets humid and not cool when i just stand still in traffic.

any ideas of what the culprits can be? what i have done so far is, i refilled the ac fluid with that r-134 stuff whatever it is called. temps came down tremendously, but, now i have this musty smell and humidity at times.

i popped open the center console vents and cleaned it out and nothing was there aside from some dust.

is there a cabin filter or something in my car that i can't find? so i can change it if that's the case.

thanks