I sprayed out of windows (still do at my house) for years and years with no problems other than the window being open and the humidity level in the house (Southern Lousiana, just a tad humid down here) rising by mid morning.
I recently built a spray booth with a big plastic storage tub, bathroom fan and dryer hose, vented to the winow, with pantyhose stuffed in the furthest end to catch the paint particles before it makes a big multicolor ring on my screen. I have this end of the dryer hose pulled thru a big slab of foam, so I can close the window, keepinghumidity and bugs out while positively exhausting the paint fumes.
total cost of the build was about forty dollars.
David
Build to please yourself, and don't worry about what others think!
TI 4019 Jolly Roger Squadron, 501st Legion