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swaff39
Electrical through a cold air return

Hi,

I am doing a reno on a 30 year old house. We are remodeling the kitchen and putting in Ikea cabinets. We moved the stove against a wall where there is a cold air return duct and I want to put the electrical box on that wall, but need to enter the duct to run the cable straight up to the new box.

Can this be done?

The stove is against that wall as per the drawings. I am running NM cable... should I run BX?

thanks,

Swaff -)

swaff39
Re: Electrical through a cold air return

Oh, and the cable will be pushed through the beams in the basement into the duct line. No electrical wire will actually touch the metal duct!

ed21
Re: Electrical through a cold air return

Pretty sure no building codes will allow wire in ducts.

function
Re: Electrical through a cold air return

Please ignore the reply from hannahmd(who is a spammer) and contact your local building inspector or a home inspector. My home inspector was none too pleased to find wiring and a gas lline in my air return, and I am actually removing it soon which leaves me with the issue of plugging the holes. and making them airtight.
I highly doubt a licensed electrician would run the line thgrough the return, so consider that if you want to do it.

dj1
Re: Electrical through a cold air return

Follow ed21 and function suggestions.

HoustonRemodeler
Re: Electrical through a cold air return

The only return "ducts" that allow for pipes and wires are in commercial settings where the entire space above the ceiling is one huge return air duct.

In my fair city there are NO pipes or wires allowed in residential ducting.

Fencepost
Re: Electrical through a cold air return

The only way I see this being permitted is if the cable is run through solid steel conduit where it passes through the duct. The penetrations where the conduit goes through would need to be sealed, and the conduit would likely need to be somewhat oversized; the ends of the conduit would need to remain open on at least one end to allow airflow through the conduit -- depending on circumstances, it may need to be sealed on one end for fire protection. (Oversized and open would prevent heat buildup in the wire. Even though it's a cold air return, a cable encased in conduit can heat up from the current flowing through it.) The conduit should be fitted with bushings at each end to protect the cable from abrasion.

Be sure to run that plan by your inspector BEFORE starting the work. Sometimes they will approve a solution that is normally in violation of code IF you've taken pains to mitigate the problems the code is intended to address. You'll need a detailed drawing, and if the inspector approves, the drawing needs to be stamped or signed by the inspector to ensure final approval.

Another option is to use conduit but rather than going through the duct, route the conduit below or around the duct. This will satisfy code requirements that prohibit running cable along the bottoms of the joists or outside of a finished wall. It might not be as pretty, but it will certainly pass inspection.

Re: Electrical through a cold air return

Only in residential applications is NM is allowed to be run through across a cavity being used as a cold air return but not along it's length.
It's also allowed in rooms where return is sucked into an air handler.

But in ducts specifically fabricated for enviromental air the 2011 NEC 300.2 (B) employing MI cable, MC without an overall non-metallic covering, EMT, FMC (with special connectors) , IMC, RMC are allowed.

All of this is to limit the use of materials that contribute smoke and combustible material during a fire.

ed21
Re: Electrical through a cold air return

Maurice,
What is meant by "ducts specifically fabricated for environmental air"?
I'm familiar with plenum rated wire & equipment, but am not familiar with the specifics.
Just trying to add to my knowledge base concerning codes.
Thanks, Ed

Re: Electrical through a cold air return
ed21 wrote:

Maurice,
What is meant by "ducts specifically fabricated for environmental air"?
I'm familiar with plenum rated wire & equipment, but am not familiar with the specifics.
Just trying to add to my knowledge base concerning codes.
Thanks, Ed

An example of a specifically designed cold air duct would be from the filter location to the inlet of an air handler where the return air would be either recirculated, heated or cooled.

BTW, no wiring is allowed in any duct used to "transport dust, loose stock or flammable vapors", including "a shaft containing only such ducts, used for vapor removal or for ventilation of commercial-type cooking equipment".

Because this section has been revised recently and some jurisdictions may have local amendments, I would consult with the inspectors before I did any duct work or plenum (now called Other Spaces Used For Enviromental Air) wiring.

ed21
Re: Electrical through a cold air return

Got it. Thanks

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