hey mister e ,
my carbon scrubber works much better if air is drawn thru it . not blown into it and pressurizing it . i've tried both ways .

the only way i see you getting away w/ only i blower is outside air in >thru cooltube >into a duct that resembles a y w/ filter on 1 leg , and like an 8in vortex or huffican drawing air thru both the tube and the filter and exhausting into the room like you were doing anyways .
peace
crispi