How I finally solved cooling my room — steps that actually worked

I did the same thing with a Whynter 12,000 BTU unit in my home office last July. I was terrified of all the "negative pressure" talk, but when my desk thermometer hit 92 degrees, I stopped caring about the physics and just wanted to stop sweating. I ended up using heavy-duty foam insulation strips around the window slider because my frame is incredibly warped from the sun. One thing that really helped my setup was insulating the actual exhaust hose. Those thin plastic hoses radiate a ton of heat back into the room while they’re running. I wrapped mine in some reflective bubble wrap and secured it with zip ties. It made a huge difference in how hard the compressor had to work. Before the wrap, the hose felt like a space heater; after, it was barely warm to the touch. You're right about the small spaces. As long as I keep my office door closed, that little unit keeps things at a steady 74 degrees even when it's triple digits outside. It’s not the most elegant solution, and the electricity cost is higher than a window unit, but it beats the alternative of being miserable for three months out of the year.

Since you're dealing with those sliding door gaps, you should really look into the Midea Duo 14,000 BTU unit. It has a hose-in-hose design that fixes that negative pressure issue everyone worries about while still being a portable. I swapped my old single-hose for a Midea last summer and the cooling speed is night and day. Plus, the window kit it comes with is way sturdier than cardboard and actually seals tight against a slider if you grab their extension piece.

Glad to see someone using thier head and a roll of tape instead of just reading a manual. Back in the day, we didn't have these fancy 'hose-in-hose' gadgets; we just made do with what we had. One thing you ought to watch for with that DIY sliding door setup is the drain pan. Those portables can spit out a gallon of condensate an hour when the humidity spikes. I used to propped mine up on a couple of cinder blocks and ran a length of garden hose straight out the gap in the door. Saves you from waking up to a soaked carpet when the internal tank inevitably overflows.