9.20.2 Ventilation Shaft

For ventilating the spaces for water closets & bathrooms, if not opening on front, side, rear & interior open spaces, these shall open on the ventilation shaft, the size of which shall not be less than the values given in table below :-

Table No.9-C - Ventilation Shaft

 Sr.           Height of         Cross-section of Ventilation    Minimum one dimension of
 No.         Buildings in m.            shaft in Sq.m.                the shaft in m.
     (1)             (2)                     (3)                               (4)
     1     Upto10                            1.2                               0.9
     2     Upto12                            2.4                               1.2
     3     Upto 18                           4.0                               1.5
     4     Upto 24                           5.4                               1.8
     5     Upto30                            8.0                               2.4
     6     Above 30                          9.0                               3.0

Note :-

a) For buildings above 30.0 m., mechanical ventilation system shall be installed besides the provisions of minimum ventilation shaft.

b) For fully air-conditioned residential / other buildings, the ventilation shaft need not be insisted upon, provided the air-conditioning system works in an uninterrupted manner, also

provided; there is an alternative source of power supply.