Dimension requirements of roof access hatch.

dimensional requirement

Manhole for personnel to pass through: the size should be slightly larger than people's shoulders, and the common size is 600mm×600mm, so as to ensure the smooth entry and exit of personnel. ‌

Equipment access port: If the equipment needs to enter and exit from the access port, the reserved size should be 200mm wider than each side of the equipment outline to facilitate the installation and maintenance of the equipment. ‌

General size options: Common manhole sizes include 300mm×300mm, 400mm×400mm, 450mm×450mm, 500mm×500mm, etc., among which 400mm×400mm is more common. For the shallow observation port that does not need personnel to pass through, 300mm×300mm can meet the demand. ‌

Consideration of special equipment: When installing central air conditioning or fresh air system, the ceiling is usually lowered by 250mm-300mm, and it is more appropriate to reserve 300mm×500mm for the manhole.