Hi i have set up a cabinet in the attick and the temp gets up to 40degrees here which is a bit over 100 degrees F. Are 4 120mm pc fans and a small oscillating fan goin to be enough and running the lights at night to early morning?
I am goin to insulate it but i am not sure wat will happen if i cant get it below 40 in some cases all the time. will the plants die or stop growing?
Any help would be appreciated

Anything over 85-90 degrees F will definitely be detrimental to your plants progress. Best to keep things in the 80 F range if you can. Hard to say what fans will work without knowing more about your setup, but you definitely need to reduce the temps. Do the 120mm fans vent outside? Any fresh air intake? What type/wattage lights are you using? What are your average outdoor temps throughout the year?

i am runnning a cfl 130-300watt with a reflector, im pretty sure i cant remember the exact numbers and the box is in the attick.
the fans push out 44.75cfm each and the hottest it gets is aroun 105 but that is the extreme days as its coming into summer now but they are not that often usually around 3o to 35 celcius
i am currently trying to get fresh air from outside but as it is stealth i have limited options but it is possible for me to make it happen
i was thinking a whirly bird in the roof might be a good idea just trying to think of an excuse to tell my mum could be a lil difficult
also i read a post about using wraping paper as one side is decorated and the other is mylar and is also very cheap so any input on that idea would be appreciated
cheers