Cooling my closet grow

Hello all. I am new to the site and new to growing as well. I've done a lot of research in all aspects of growing,(lighting,conditions,etc.) I am currently having a problem in making a decision about efficiently cooling my grow area. I have taken a 4'w x 2'd x 7't grow tent and set it up inside of a closet that is perfect size for the tent with about 6 inches to spare on all sides. 400w MH grow lamp with wing reflector. I have it set this way for security and concealment purposes. the tent itself has various vent holes for ventilation for an inline fan or inline booster, however i rent my place and cannot drill holes or cut holes in walls for vent. exhaust. Ive looked at air coolers and mini a/c units but all look expensive and more of a hassle with humidity and etc. maybe inline fan or a decent fan booster on each side , but how much length of duct can i put on a fan like that without having loss of power? I'd only need maybe 2ft or a little more on each side to snorkel it up and out and just leave the door cracked enough for the ducting to vent? Any suggestions and help is greatly appreciated. Pics attached.

Sounds to me like all you need to do is make some sort of exhaust vent in the top of your tent and just let the air flow into the closet that way (assuming you have 6in of closet space above the tent, right?). Then, you can keep the door ajar and it should be enough to get the hot air out of the tent, however the hard part will be getting fresh air inside.

Currently, I'm in a similar situation and I simply have a dryer duct laying on the floor that goes into the closet when its lights out. I cut a hole in the ceiling for the exhaust though. Set up the light schedules so I'm mostly home when lights are on. I'm using a 400w HPS and those things get fucking hot, man. Maybe invest in a cooltube, it will help with the heat tremendously (it did for me).

cooling the light with a cooltube that just draws air from the tent would prob work well for setup. Putting any amount of vent on the fan is gonna restrict it some.

Check out my sig for a cheap inline fan.. its great for air in and/or out and is very cheap to do. I use this on a 6x8x8 grow room and works absolutely awesome!

It alone cooled my grow room by several degrees.

The DYI inline fan is crafty, but most of my vent holes are near the top and it would be impossible to hang and setup one of those with only 6 inches to spare. the tent zips up and then i can close the door. with the tent zipped up and door ajar do you guys think i could get away with having boosters on each side with ducting? what kind of CFM would i need for the intake and exhaust? Thank you for your reply's.