Rectangular Vs Round AC ducts
Rectangular Vs Round AC ducts
(OP)
Hi- I would like to know in the HVAC mechanical system, when should we use rectangular ducts (I think it is called the Trunk line) and when we should use round ducts.
And what is the rule of thumb for transitioning from rectangular to round duct.
And when do you use flexible round duct.
And is the return line back to the units has the same rules.
And what is the rule of thumb for transitioning from rectangular to round duct.
And when do you use flexible round duct.
And is the return line back to the units has the same rules.





RE: Rectangular Vs Round AC ducts
Return ducts are often rectangular as the flow path is less critical, sealing is less critical and the runs are usually shorter.
Flex duct should be used only to connect a branch duct to a diffuser, and even then try to keep the length of the flex to under 4'.
RE: Rectangular Vs Round AC ducts
RE: Rectangular Vs Round AC ducts
Lower hydraulic radius=less pressure drop.
RE: Rectangular Vs Round AC ducts
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: Rectangular Vs Round AC ducts
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: Rectangular Vs Round AC ducts