supply air below connection with frame [duct]for sidwal/intec make rmpuof lhb type ac coaches as per sidwal part no sr-075-1056 or intec part no ic-075-1056[cotton canvas used in duct shall be as per rdso spec no rdso/pe/spec/0136-2009[rev-0] as per drg.no. - specn: rdso/pe/spec/ac/0061/2005[rev-1] .
