High Speed Roll up Doors

[georgedvf]

Hello!

I'm doing research about High Speed Roll-up Doors for Cold Rooms and Freezer Rooms.

I've heard there's energy saving using this doors, based on the opening time of the doors, but there's one thing I can not understand (yet): if the R value of this doors is about 1.5ºC-m2/W isn't there a lot higher heat transfer even when door is closed?

Thanks!