Double Wall Insulated Ductwork

Dual wall also called double wall insulated spiral pipe.

Double wall insulated ductwork.

The acoustical thermal insulation can be used with air velocities up to 10 000 fpm and temperatures up to 250 f. Double wall duct has a complete line of compatible fittings. It can reduce radiated noise by 25 db or more compared to fiberglass duct board. When a perforated inner liner is specified a retaining fabric must be wrapped between the perforated inner and the glass fiber insulation.

Insulation it is comparatively easy to insulate a double wall spiral duct compared to a rectangle wall duct. The insulation in our double wall spiral and fittings has both acoustical and thermal benefits. Fittings can be fabricated with standing seam elbow lock or welded seam construction. Our double wall duct and fittings also control radiated noise better than similar sizes and shapes of externally insulated sheet metal duct.

Dual wall insulated spiral pipe consists of two concentric spiral pipes with insulation filling the space between the pipes. This double wall insulated ductwork is constructed of a solid metal outer pressure shell and a metal inner liner with a layer of insulation sandwiched between. Sheet metal connectors inc. Cost dual wall spiral duct is relatively affordable compared to the rectangular wall duct.

In double wall rectangular duct a metal inner liner insures that high airflow velocities cannot separate insulation by pulling away from the duct s outer wall and creating erosion or airflow problems. All double wall ductwork and fittings shall be constructed with an outer galvanized wall and a perforated inner galvanized liner. Duct liner shall be of the specified materials thickness and density of the contractors request. Zen s 1 inch insulation has a thermal conductance of 0 27 btu hr x sq.

Double wall duct and fittings can reduce radiated noise by 25 db or more compared with fiberglass duct board and by 30 db or more com pared with insulated flexible duct. Ductwork will be spiral seam construction made from g 90 or better galvanized steel conforming to astm a653 a653m and a924 a924m standards lock forming quality lfq. Double wall duct and fittings will consist of a perforated or solid inner liner 1 thick x 1 0 lb ft layer of glass fiber insulation and a solid outer pressure shell. It is insulated from the outer parts compared to the rectangle wall duct which has to be insulated from the inner sections.