4 inch exhaust fan and a not very good bathroom extractorwhat kind of out take or exhaust are you using
there is another hydro shop near me, i will give them a ring tomorrowive got this one and love it! http://www.rightpricehydroponics4u.co.uk/powerplant-aircooled-aerowing-reflector-no-cord-374-p.asp it was only £70 from my local hydro store, there no heat comes off and you can touch the glass and its barely warm,
what do you think of the silverstar one ?????i would do 6 m8 only because i know 100% a 6 inch 450 cfm fan is enough to cool a 600 light and most likely the room its in at the same time. (depending on size of room)