The different types and models of quick-acting doors provide you with a broad choice of features. Their relative advantages and disadvantages may not be obvious, so pay attention to the details. Consider the following characteristics of quick-acting doors in relation to your particular applications.
-Speed of Operation Quick-acting doors typically operate at a speed of one to three meters per second (three to nine feet per second). Quick operation is important to minimize interference with traffic and to reduce the chance of hitting the door. The door may close more slowly than it opens. Opening quickly is more important than closing quickly, so the door may have a spring to assist the motor in opening the door. When the door closes, the motor mustovercome the force of the spring. Some vertically rolling doors close by gravity, whereas the other types require power to close. Slower closing may be important for safety, since the closing cycle poses more of a danger than the opening cycle. Slower closing allows more heat loss, but this effect is minimal at the high speeds at which the door operates.