It is best to transport the air conditioner upright. If it necessary to transport the air conditioner on its side, it should be stood upright and unplugged for an equal amount of time as it was on its side. If on its side for more than a day, leave standing upright and unplugged for 24 hours.
Note: If laying the unit on its side briefly to service, clean or adjust, a few minutes of stand time will be enough.