Flight was delayed for four hours before anyone got any answer, which answers were not accurate. Airliner had mechanical problems, however plane was boarded six hours after initial departure time. Sat on plane for three hours without any appropriate air flow on the plane. Plane turned back to terminal advising us that we could not depart, at this time it is 12am. Poor organization from ground staff, cabin crew very bitter. Airline did not provide overnight accommodations (plane was to depart again at 8:30am) most people who decided to stay slept on airport floor. Airline did not provide food or water until 6:30am which at that time they provided coffee and hamburgers for breakfast. Plane boarded again at 8:30am, one hour later advised by captain that one door would not close and the maintenance crew had to come on board, by noon we had finally departed Vancouver. On return we were advised that an aircraft most likely the same airline had to make an emergency landing twice due to mechanical problems.