need help with lighting and humidty

i have a 600w hps light my grow room is 3x3x3xfoot and i haveing proplems with humidity its 0 i dont have a exhaust fan or nothing yet i was think about getting a cooltube and duction fan im growing white widow will this help the temp is like 94 under light if i buy a cooltube can i use the 600w hps from start to finished (using seeds )​