I have a portable A/C unit with a flexible hose for venting its exhaust. It doesn't seem to have any condensate output, so I'm thinking it must just run its condensate through the flow of heated/exhaust air and lets it evaporate out that way. As my landlord won't let me cut a hole in my windows, last summer I'd just opened my window far enough to stick the whole exhaust hose out and then insulated the rest of the opening with bubble wrap and tape as best I could-far less than ideal. In the meantime I noticed I have a chimney access panel for my hot water heater's exhaust in my apartment. Basically it sits about 6' below the exhaust for the heater and is meant, I guess, as a test/cleaning panel. It is, however, nearly exactly the right size to fit the exhaust hose into, with only a little tape/insulation around to keep it in place and make a tight seal. Does anyone see why that wouldn't be safe or wouldn't work well? It's hot air I'm exhausting, so it'd keep the draft running in the chimney. It's below the exhaust entrance for my hot water heater, so I can't see how it'd interfere with that (and the heater itself has about 6' of its own flue first, so I don't think it'd back up into that). The only worry I have is whether it'd potentially cause some sort of interruption of the draft and maybe cause some carbon monoxide buildup, but I'd plan on buying a CO detector if I did this anyway...