You can not only manage this space, but dial it in to perform very well. Good news here is you can clear all the air in there very fast with minimal investment. You will need an 8 inch duct fan, in line. The thing will move a huge amount of air, you might find your door sucks shut totally. This negative pressure is great. So outlet above all heat sources like lights etc. You will need an inlet of at least six inches in size to make use of the full extraction power of the fan. You will be moving many cubic feet per minute. Many. Your outdoor temps are fantastic. You will probably be nicely surprised with a dry run once tour vents are installed. For your kind of setup, RIU user
@prosperian put together the most amazing stealth room if you look him up you will be very impressed. LED... is over rated. One point people constantly forget is LED can only ever cover sixty percent the floor area HID can, you need to keep LED a lot further away from plants than cooled HID, and good LED can set you back close on 3000USD for something like a BML Spydr. Too expensive to just sort out a little bit of heat IMO. Your HID will pay for itself first run even if that run ismt all that great... Get your vents sorted now and you are almost there!