There are forms of these that are temporary. Some restaurants and bars will put one up in the winter; typically made of heavy canvas rigged across a metal frame, often with clear plastic window inserts to keep users aware of traffic coming in the opposite direction.
Most often, the primary motivation seems to be to increase guest comfort by preventing cold blasts. But they also aid energy efficiency.
I just dined at a nice restaurant that had a set of heavy velvet curtains in a semi-circle around the inside of front door. Not only did it prevent cold blasts to the tables close to the door (I always hate that) it made for a really elegant transitional experience between the dull outside space to the exquisite interior.
There are forms of these that are temporary. Some restaurants and bars will put one up in the winter; typically made of heavy canvas rigged across a metal frame, often with clear plastic window inserts to keep users aware of traffic coming in the opposite direction.
Most often, the primary motivation seems to be to increase guest comfort by preventing cold blasts. But they also aid energy efficiency.