With natural ventilation, the cross-sectional area of the ducts must be appropriate to the air flow required at velocity of 0,5 m/sec. It must be not less than 80 cm? for lead-plate batteries and not less than 120 cm? for alkaline batteries.
Online Language Learning Tool SkELL allows users to search for phrases in sentences, collocates and similar words. These examples have been automatically selected and may contain errors.
