Which would be better?

I currently have some heat problems in my grow closet. On one hand, I can crack the door and vent the heat with a fan shooting cold air directly up which brings the temp down to about 78, or have the fan shoot in the crack under the door to keep the temp around 90. Cracking the door loses some light, so which I do?

I have a 400 watt HPS in there and a circular fan inside the closet throwing some breeze around.

Any Ideas?

link to grow is

https://www.rollitup.org/grow-journals/288791-4x-feminized-raspberry-cough-400w.html

Would rather lose a little light than burn my plants. People grow fine with CFL so if u got a HPS, nothing to worry about. Me, I'd cut into a door and just make ventilation in it since hollow core doors are like $20

I rather have some light leak out then let my plants sit in 90+ temps. And just tossing this idea out there, but you could leave the door wide open, then hang a white sheet. Breathable and reflective.

Ill keep it cracked then. Did not even think about the white sheet idea, thanks a lot guys.

you are going to need a different solution when it comes time to flower. you have to keep light from getting in during the 12 hour dark cycle.

the fan blowing around is not going to do much for heat if it isnt bringing in cooler air. your best bet would be to figure out some way of making a cold air intake. My suggestion would be make a hole in the lower part of the door and run a dryer vent from under a dresser or something (because you dont want light leaking in during the dark hours.) install a small pc fan or something similar to force the cooler air in. you should be able to do this for under $30.

Thanks for all the help, I am going to try and throw in some kind of ventilation system, but for the time being I will just remember to close the door before the lights go out. They are about 30 days into flowering right now, and I usually close it about 20 mins before it goes out so it can build up some heat to last through the night, it tends to get kind of cold.