All double wall ductwork and fittings shall be constructed with an outer galvanized wall and a perforated inner galvanized liner.
Double wall insulated ductwork.
It is insulated from the outer parts compared to the rectangle wall duct which has to be insulated from the inner sections.
Duct liner shall be of the specified materials thickness and density of the contractors request.
Thermaduct s inspiral r and floval duct systems are preinsulated spiral and flat oval double wall ductwork alternatives that offer significant weight savings and near zero air leakage.
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.
Our double wall duct and fittings also control radiated noise better than similar sizes and shapes of externally insulated sheet metal duct.
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.
Constructed of a solid shell surrounded by a layer of insulation and covered by a solid outer shell.
Dual wall also called double wall insulated spiral pipe.
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.
Sheet metal connectors inc.
Fittings can be fabricated with standing seam elbow lock or welded seam construction.
The acoustical thermal insulation can be used with air velocities up to 10 000 fpm and temperatures up to 250 f.
Zen s 1 inch insulation has a thermal conductance of 0 27 btu hr x sq.
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.
It is shipped from the factory with the insulation pre installed reducing job site labor costs.
It can reduce radiated noise by 25 db or more compared to fiberglass duct board.
Cost dual wall spiral duct is relatively affordable compared to the rectangular wall duct.
The insulation in our double wall spiral and fittings has both acoustical and thermal benefits.
Dual wall insulated spiral pipe consists of two concentric spiral pipes with insulation filling the space between the pipes.