What is Smacna standard?
SMACNA standards help contractors reduce costs, anticipate technical requirements, and increase productivity and efficiency. SMACNA standards and manuals address all facets of the sheet metal industry, from duct construction and installation to air pollution control, energy recovery, and roofing.
What is dw144 standard?
DW/144 is the Standard Specification for ductwork manufacture and installation and is aligned to all current BS, BS EN ISO and other standards and regulations.
How far apart should duct hangers be?
But the underlying “common sense” behind those recommendations is pretty simple: have no more than two duct joints between supports. That explains the 8 to 10 feet apart recommendation when you are installing 4 and 5 foot joints of rectangular duct.
Is Smacna a union?
California Association of Sheet Metal and Air Conditioning Contractors, National Association (CAL SMACNA) is a non-profit statewide trade association representing over 600 sheet metal and air conditioning contractors who employ more than 25,000 union employees and administrative personnel throughout the state of …
What is DW145?
BESA Product Code: DW145 It identifies, clearly and concisely, the matters that must be addressed when fire and/or smoke dampers are to be installed within a building’s ventilation ductwork system.
What is the maximum operating pressure in an air duct system?
Usually the static pressure is limited to a maximum of 7 inches WC, and duct velocities are limited to 4,000 fpm. Systems requiring pressures more than 7 inches WC are normally unwarranted and could result in very high operating costs.
How often does ductwork need to be supported?
every once 4 feet
Supports should be installed at least every once 4 feet. The maximum allowable sag in flexible duct is one-half inch per foot. (Source: Calcs Plus.) Place supports at each connection between flex duct and rigid metal duct.
What are duct hangers?
Duct Hangers are designed to pull rectangular trunk duct work up tight to the bottom of joists. They can be easily assembled on the floor prior to hanging. These hangers can be attached to wood or metal framing with a maximum 10 foot interval.
When was Smacna established?
1950
Established in 1950, SMACNA St. Louis serves member contractors and experts in four core industries across the greater St. Louis area: architectural, HVAC, industrial and residential.