The foul air is exhausted back to the weather deck through trunking, either naturally or by exhaust fans .
Umoya omdaka ukhutshwa ngombhobho wokukhupha umoya omdaka uphindiselwa kwidekhi yemozulu kwangale mibhobho isesiqwini, mhlawumbi uziphumele ngokwendalo okanye ngamaphiko ombhobho wokukhupha umoya omdaka.