4" Vortex fan, air blows in or out? HELP

[NOOB QUESTION]

so I have a 1000w MH/HPS running in my cloest with a 4" inline fan hooked to it with 4" venting.

QUESTION: Is the air supposed to get sucked in from an outside source and cool the bulb, or its it supposed to suck the heat away from the bulb and exhaust it out to an outside source? I have seen it dont both ways and was wondering which is most effiecient for keeping temps low.

I guess I could expieremnt and see which has lowest temps, but I'd rather just ask. THANKS.

and happy growing.

Sucking through the light, blowing you're hot air away from the light/plants/closet. You're fresh air will be drawn in to the grow area.

pics...
https://www.rollitup.org/attachments/grow-journals/213073d1223530854-stealth-hydro-bubbleponics-growing-topp-dsc00027.jpg

https://www.rollitup.org/attachments/grow-journals/213078d1223530915-stealth-hydro-bubbleponics-growing-topp-dsc00028.jpg

if smell is an issue then you must blow the air out so you can control the odor.

ok sweet, quick response...

thats how I have it setup right now...BTW plants are closer to the light than in the pic.

yah I could put a carbon filter on the end of the exhaust. right now $$$ is the issue