Help needed with cabinet grow

My cabinet is approx: Height-52", Length-21", Width-18".

My problem is that I having difficulties in finding a silent way of extractor air so that their is fresh air circulating.

Ive considered small squirel cage blowers & 5 x PC fans (12v) but because of the voltage Ill have to use too many batterys.

Any advice or links to any products that may help?!

Anyone..............

for pc fans mod a mobile charger or use a pc power box im sure theres summat on the chargers here in diy