you will still have to run the exhaust ducting from the portable ac to your window to exhaust. They come with a window plate that has a hole in it for the ducting. Having an ac in your window will you be able to rig it to exhaust the hot air? You won't find them cheap. They are pricey no matter where you shop. The cheapest one I could find was just under $200. What I do is take my closet door off, cut black plastic sheeting to fit over the opening and fasten with velcro stickies. One 6 inch hole near the top to send ducting out for exhaust with a 6" inline duct fan. One 6 inch hole near the bottom to draw in cool are with another 6" inline duct fan. I use black duct tape around the gaps of the hole for light leaks. I keep an oscilating fan in the closet with another fan blowing over the canopy cooling the heat down from the light. I keep my room as cold as possible so the air coming in through the intake is able to keep the closet below 80F. During lights out I have another piece of plastic sheeting that I run at an angle from the start of the opening of the closet to the wall to the left of the closet....double dark
This keeps it totally light proof while still being able to drop the temps at night by 5-10F. I just have to adjust the intake fan on the room side of the makeshift tent to draw in the coolest air when the lights go out.