do i need a cooltube if i get a portable a/c?

I'm going to be flowering with a 400w hps and dont currently have a cooltube or a diy a/c yet but was wondering if i need both or can i just get away with the a/c?

the room is about 2.5ftX3ftX8ft.

temps got up to 120F before i started my plants about 6 weeks ago or so and i dont want to fry them by accident because it got too high.

i would say both u need to vent tat cooltube and the air

Thanks I have seen a couple diy cooltubes and I know how to make them but I haven't figured out how to wire the new socket to my already existing ballast. I have the HTGsupply 400w switchable but it is just sitting there because the temps were too high previously. I've been waiting for a door to be modified by a friend so I can get some ducting and ventilation put in but I'm kind of dependent upon them to do it. Anyone know how to wire the ballast to the new socket? +rep to anyone that can. Thanks