HVAC duct construction standards metal and flexible
This Second Edition of the SMACNA commercial metal and flexible duct construction standards is another in a long line dating from the 1950s. A quick overview of the changes is provided at the front of this manual. Meanwhile, a Committee has already begun work on what will be either addenda or a new edition. Subjects being investigated are ribbed round duct, fatigue testing of tie rodded metal, new flat oval duct standards, duct liner pin lengths, more double wall casings, sealant specifications, and more performance specifications for joints and reinforcements. And, indirectly related to these standards, significant progress is being made by major mechanical code writing agencies in developing one uniform, consensus-supported code for the entire nation.