If the designer does not designate pressure class for duct construction on the contract drawings the basis of compliance with the smacna hvac duct construction standards is as follows.
Smacna duct support on roof.
Tip you can figure the load on a duct of half of the width using table 2 46 and then double the load.
Roof hvac duct supports unistrut roof support system bases roof crossover stairs crossover ramps s 5.
The types of fittings to be used based on the designer s calculations of fitting losses i e square versus 45 entry taps conical versus straight taps etc.
Brackets curved unistrut channel.
Page 2 106 the load is 146 lbs load for 70 inches x.
For all other ducts of any application.
140 2 70 inches rs 28 inches duct over 120 inches.
Ducts are suspended from hangers 12 in.
Duct dimensions duct dimensions shown in the contract.
The php d duct support leverages a goal post design with a single crossbar below the duct to support all sizes of square or round ducting cable trays and piping.
Duct construction ductwork and supports shall conform to the hvac duct construction standards metal and flexible third edition 2005.
Or less as measured from the top of the duct to the bottom of the support where.
Snow retention systems zsi safety products s 5.
A copper roof was used on the rebuilt old senate chamber in 1819.
Information required for duct construction 1.
Miro industries is excited to announce the official arrival of the latest addition to the miro product lineup the model 3 0.
For all ducts between the supply fan and variable volume control boxes and 1 250 pa w g.
Solar attachment clamps for metal roofs unistrut tools hardware s 5.
Sheet metal and air conditioning contractors national association 4201 lafayette center drive chantilly virginia 20151 1219 tel 703 803 2980 fax 703 803 3732.
Seismic supports are not required for hvac ductwork when the i p 1 0 if either of the following conditions is met for the entire duct run.
Featuring a similar design to the time tested model 1 5 the model 3 0 is just as simple to install and is guaranteed to withstand harsh rooftop conditions for years to come.
2 500 pa w g.
Substrate failed early metal roofs were batten style or flat seamed until.
Where fittings of configurations not shown in the hvac dcs are shown on the contract drawings they shall be constructed as though they were therein.
Duct over 120 inches.
A comprehensive duct layout indicating sizes design airflows pressure class and routing of the duct system.
