• (A) Presence of a non-condensable gas decreases the condensing film co-efficient
• (B) Gases under high pressure are routed through the tube side, because high pressure gases are corrosive in nature
• (C) Gases to be heated/cooled is normally routed through the shell side, because the corrosion caused by the cooling water or steam condensate remain localised to the tubes
• (D) All 'a', 'b' & 'c'