2.2.2 Bolted and gasketed access doors, minimum 600mm x 600 mm (24 in. x 24 in.) shall be provided in the scroll and inlet box(s) to access the fan internals for inspection, cleaning, rotor balancing and any internal bolting necessary for rotor removal. If fan size and construction will not permit this size access doors, the largest practical access openings shall be provided in the scrolland inlet box(es).