Thermal performance of door systems - insulated doors may not be the answer.

Discusses 2 reports by the Agrement Board which indicate that insulated doors in busy industrial buildings such as warehouses do not save much energy. Further studies by the Bolton Gate co. show that the addition of a plastic strip curtain gives significant savings. When a door is open for 5 mins perhour, the mean saving can be 15% depending on outside temperature and the air leakage of the curtain. When the door is open for 15 mins per hour, the mean saving can be 29%. States that it is easier to use plastic strip curtains with horizontal folding shutters than with doors.