Thanks everyone for all the advice. It's quite daunting. I'll give it another go, but this time on a warmer day. That way, if I smoke up the place again, I can air it out easier!!!
I do think that some of the smoke came from the "never used" stove. I could see smoke coming off the casing. But I don't think that explains it all.
Once again, thanks to all...... but Dooleysm. You would expect an IU fan to act like that, wouldn't you!!! lol
Josh