Have you ever wondered why most buildings on campus have a set of double doors at their entrance? The area between the doors is called a vestibule and it acts to keep you more comfortable and to save energy. Instead of the cold outside air entering the building every time the door opens, it mixes with the buffer air in the vestibule and is warmed before entering the building. By trapping the air between the entrances, the vestibule acts as a buffer to the cold and can achieve as high as 3% energy savings this time of year.
On average, vestibules save between .68-.90% of the total energy usage of a building. Sure, that’s not a huge savings, but it sure feels a lot warmer than cold air blowing through Jordan Hall. It also helps keep the building cleaner. So try to avoid having both doors open at the same time and take care to keep the doors closed after you go through them.