pipes in hvac return

[John Arnold]

What do ya'll make of this? Pipes passing through return air.

[Joe Laurieri]

I know electrical wires thru an HVAC return is ok.

never ran thru that situation before.

I am thinking that depending on the use of the pipe and type of material I would not recommend it.

i.e. hot or cold copper pipe runnin in duct. potential condensation in with the air return to furnace and then being sent thru the house.

As well as temperature of the portion of the pipe running thru the duct different temp than rest of pipe. What does that do to the service life of the pipe?

As well as needing to seal up all those holes !!!

Real mess - just go around it i say.

[Jerry Peck]

What do ya'll make of this? Pipes passing through return air.


I know electrical wires thru an HVAC return is ok.

Typically not okay. There are limitations on electrical conductors running through return air ducts and plenums.


i.e. hot or cold copper pipe runnin in duct. potential condensation in with the air return to furnace and then being sent thru the house.

As well as needing to seal up all those holes !!!

Real mess - just go around it i say.

I agree, just go around, the only way to know if the potential problems exist is to take the duct apart, in which case the pipes may as well be re-routed around the duct.

Now, a gas like or a DWV line through a return duct - that is a definite no-no.

[Jack Murdock]

Is it a duct or a plenum? It looks like copper water or heat lines and a black steel gas line. There is nothing preventing gas lines through a plenum unless its a local AHJ distinction...

[John Arnold]

Is it a duct or a plenum? It looks like copper water or heat lines and a black steel gas line. There is nothing preventing gas lines through a plenum unless its a local AHJ distinction...

It's a return duct. The black gas line isn't penetrating into the duct.

[Jack Murdock]

John,
Its OK to run gas water or electrical in a plenum just not through ductwork

jack