The door should have an effective method of sealing each edge of each panel or sheet. Each edge is a separate sealing problem. Examine how the manufacturer deals with the top, the bottom, and the sides. In the case of double doors, examine how the manufacturer closes the gap between the two halves. In the case of segmented doors, examine the sealing between segments. All seals eventually wear out from flexing and abrasion. Check that the seals are installed in a way that makes them easy to replace. If the seals are specialized, you will be dependent on the manufacturer to provide replacement seals in the future. The bottoms of vertically moving doors are usually sealed with a large, hollow cushion seal. These work well. The bottoms of folding doors usually have sweep seals. These work fairly well, but the seals wear on an uneven floor, and the drag of the seals tends to keep the door from closing fully near the bottom. Horizontally rolling doors may have no bottom seals. Minimizing infiltration with this type of door requires careful installation to minimize the size of the gap. With double folding or horizontally rolling doors, look for an effective seal where the doors meet. Some doors rely on a large, soft edge seal. This method may not seal well, because the edges may not meet properly. Some models have magnetic seals installed in the edges to provide effective closure. With rolling doors, pay attention to the manufacturer’s method of minimizing air leakage where the edge of the sheet slides in the track. This part of the door design is a compromise between air leakage, reducing a tendency to jam, and breakaway during impact. Also, make sure that there is an effective seal between the door frame and the roller. With folding doors, look for effective closure at the top and bottom. Some folding doors have a curtain of lighter fabric that seals the gap between the top of the
door and the sliding track. The bottom of the door should have effective sweep seals. With overhead segmented doors, examine the method of sealing the top and sides. It is a challenge for the manufacturer to combine good side sealing with
effective breakaway