Portable AC unit and other options

Here's what it is, guys. My friend is setting up a system in his closet, he has no air cooling ventilation other than his 3 fans and leaving the closet door cracked (it's about 2' away from the room's AC vent) and when he turns on his 400W light it takes the room temp to over 90 degrees WITHOUT any fans on. He looked into Portable AC Units to help cool the room but they all have window exhaust and cool a room of 200 square feet when his closet is probably less than 50, it seems like the portable ac unit would be too much for the size of his room...I'd think there's gotta be something a step under that will do the same job since there's not a lot of area to cool off.

What are some other options out there to help sufficiently cool a room (50 sqft) other than a portable AC unit?

an air cooled reflector should bring your temps down to reasonable levels. you will need an inline fan, I would think 4 inch 165cfm could cool a 400 just fine, (do some research.) a vented hood, and some flexible duct.

and once you start sucking air out, you will have negative air pressure, which allows for a passive intake to constantly refresh your room with new air.

good luck!

I have pretty much the same setup and the same heat issue. 400w in a closet is an oven. Following this one.

you might ask void object how his is working out. he recently said something about buying an ac/dehumidifier that had no exhaust. how that works I have no clue, the heat has to go somewhere I'd think. find him here....... https://www.rollitup.org/dwc-bubbleponics/522383-vo-grow-4-super-silver-8.html

Thanks for all the info, guys.
Good advice DB, I have been keeping up with VO and his video journals and I noticed he had purchased an AC/dehumidifier in his last video so I checked into it. The majority of portable AC units/dehumidifiers need a window exhaust and that's not ideal for my friend so we looked into Air Coolers/Humidifiers (still a couple of hundred bucks) and they won't cool as much as a AC unit (I've read anywhere from 10-20 degrees) but they don't need an exhaust and we figured an Air Cooler that is meant for a 300-500 square foot room should do a 50 square foot closet NO problem (right?)..the only negative is that you have to refill the reservoir pretty frequently and if the cooler is kept on "high" than that could be every 4 hours (Not good since I work 8-9 hour days).