Air cooled hood AND room ventilation confirmation?

Hey guys, I think my brain is getting fried from all the reading...

So here it is... I'm just about ready to buy fans for my 4x4x6 cab.

I will have a 6" air cooled 400w HPS, w/ carbon scrubber/filter.

Now, research tells me to buy a 6" 400cfm vortex blower.

Filter>duct>light>duct>fan exhausting out cab

i get that the air exhausted from the light will be "clean", but I know I should also vent the cab itself.

I was thinking another 400cfm, 6" vortex w/ passive intakes.

QUESTION: Does the cab air need filtering too? I would assume that smell would escape through the cab exhaust?


Any input/tweaks are welcomed and taken graciously! Thanks!

Get a temp controller for day and night settings like the TMP-dne. You will only need one fan and filter. http://www.ebay.com/itm/CAP-TMP-DNe-Day-Night-Temperature-Control-Thermostat-TMPDne-Temp-Controller-/130626780357?pt=LH_DefaultDomain_0&hash=item1e69f67cc5

Just so I am understanding correctly, I just need the fan/filter/aircooled hood set up with passive intakes? I def like the fan controller idea. Thanks for that also!

yes. the fan will run as fast as it needs to maintain the temps you set. When the light is off it will drop to your night temp. it uses a photo cell to know when the light is on.

Awesome. Thanks for the advice!