SE-14-C067 -- Advanced Non-Intrusive Duct Lining Technology for Rehabilitation of Deteriorated Ducts in Residential Buildings PDF

Air leakage in forced air duct system is acknowledged to be a major source of energy losses in both residential dwellings and commercialestablishments. A recent study reported heating and cooling systems use nearly 60% of total energy consumed in a residential dwelling. In NorthAmerica, each year more than $5 billion worth of electrical energy is lost due to leaky ductwork. This paper presents an innovative liningtechnology developed using ultra-thin liner material impregnated with Class I fire retardant resin to restore the air tightness of aged HVAC ductsystems. Re-thinking every aspect of a generation old lining technology Cured-in-Place Pipe (CIPP) used for rehabilitation of buried pipelines, thisinnovative HVAC lining system utilizes a newly designed liner, an efficient wet-out system, and an innovative installation procedure to yieldsubstantial cost savings in terms of materials and labor. The technology enables the liner to engage multiple 90° bends in circular and rectangularduct geometries with formation of minimum wrinkles, although sealing the gaps and openings up to 8 in. (203.2 mm) in diameter, while addingminimum weight to the existing duct system. Full–scale demonstration in two residential homes in Ruston, Louisiana was performed successfully.Standard duct-blaster tests revealed as much as 90% reduction in energy losses through the duct system.