help! new grow groom!

hi peeps..

i started building this room about a week ago and i will post all the info on it later as well as the pics but i have a problem right now... i am using a 600w HPS with a cool tube and an inline fan to pump the hot air from the light away... i am also running an portable A/c in the room to keep the temp down. i have a vent in the bottom corner of the box so that there is constantly new air going inside the box... my problem is that the inline fan just sucks the cool air from the A/c out and brings hot air in through the vent in the bottom corner, so my room is staying at about 85-90F midday.. should i cut another hole in the roof and have the inline fan suck air from outside? if so, will i have enough air/co2 circulating in the room?

below are some pics... sry about the quality... they are pics from my phone

Cut a new hole for intake for the light, you will see a big differents in temps.

thats what i thought. but will the a/c pull enough NEW air into the box?

How about cutting a new hole for air out mount a fan to the air in and to the air out and you might not need that A.C as much

ooooooooooooo trust me i need the AC it is around 100F here during the day and this box is in a shed out back