fönstret: http://sv.forvo.com/search-sv/f%C3%B6nstret/
How would it be a more "realistic" construction for day-by-day, or just "Öppna fönstret" is ok? "Öppna fönstret, tack|snälla" or "Kan du öppna fönstret", maybe?
Your suggestions are more polite, and the original phrase sounds more like an order :).
Tack så mycket!