(2)If in any part of a factory the Inspector, having due regard to the weather conditions than prevailing, considers the atmosphere to be unduly vitiated or stagnant and that this is due to insufficient openings, he shall by written order require the manager to-(a)increase the openings in the walls or in the roof to an aggregate area equal to 75 per cent of the area found by the applicable formula in Appendix I or to such less extent as he deems reasonable in the circumstances, or(b)provide mechanical means to produce a continuous change of air at the rate of three complete changes in the hour or at such rate as he deems sufficient in the circumstances.
