Wenatchee Home Inspection Services

So in the cable goes and channel surfing is on! But hold your remote there cowboy, not so fast. Did you ever wonder if you can use a return air duct for a cable run?

The answer is…. Maybe. If you use the right materials and methods.

There are requirements required if cables are in the return duct. First they should be associated with the HVAC system and plenum rated. Now there are a few exceptions. You can cables perpendicular to the run as allowed in 300.22(C) exception

2014 NEC 300.22(C)
Exception: This section shall not apply to the joist or stud spaces of dwelling units where the wiring passes through such spaces perpendicular to the long dimension of such spaces.

 

From the 2014 NEC Handbook-

“This exception permits cable to pass through joist or stud spaces of a dwelling unit, where the joist space is used as a return for a forced-air central heating or air-conditioning system. As shown in Exhibit 300.20, the joist space is covered with appropriate material, and the cable passes through the space perpendicular to the vertical run. The exception does not permit equipment such as junction boxes or device enclosures within this space unless the wiring method employed and enclosure type used meet the requirements of both 300.22(C)(1) and (C)(2).”

For the rules-



From the 2014 NEC-
820.113 Installation of Coaxial Cables

Installation of coaxial cables shall comply with 820.113(A) through (K). Installation of raceways shall comply with 820.110.

(A) Listing.

Coaxial cables installed in buildings shall be listed.

Exception: Coaxial cables that comply with 820.48 shall not be required to be listed.

(B) Fabricated Ducts Used for Environmental Air.

The following cables shall be permitted in ducts as described in 300.22(B) if they are directly associated with the air distribution system:

• Up to 1.22 m (4 ft) of Type CATVP cable

• Types CATVP, CATVR, CATV, and CATVX cables installed in raceways that are installed in compliance with 300.22(B)
  
  

Informational Note: For information on fire protection of wiring installed in fabricated ducts see 4.3.4.1 and 4.3.11.3.3 of NFPA 90A-2012, Standard for the Installation of Air-Conditioning and Ventilating Systems.

(C) Other Spaces Used For Environmental Air (Plenums).

Informational Note: For information on fire protection of wiring installed in other spaces used for environmental air, see 4.3.11.2, 4.3.11.4, and 4.3.11.5 of NFPA 90A-2012, Standard for the Installation of Air-Conditioning and Ventilating Systems.


More information from the NFPA 90A

2015 NFPA 90A
4.3.4.1* Wiring shall not be installed in air duels, except as permitted in 4.3.4.21 through 4.3.4.4.

4.3.4.2 Wring shall be permitted to be installed in air ducts only if the wiring is directly associated with the air distribution system and does not exceed 1.22 m (4 ft).

4.3.4.3 Wiling permitted by 4.3.4.2 shall be as short as practicable.

4.3.4.4* Electrical wires and cables and optical fiber cables shall consist of wires or cables listed as having a maximum peak optical density of 0.50 or less, an average optical density of 0.15 or less, and a maximum flame spread distance of 1.5 m (5 ft) or less when tested in accordance with NFPA 262. Standard Method of est for Flame Travel and Smoke of wires and cables for Use in Air-Handling Spaces, or shall be installed in metal raceways without an overall nonmetallic covering or metal sheathed cable without an overall nonmetallic covering.

4.3.11.3.3 Electrical wires and cables and optical fiber cables shall comply with 4.3.4.

Remember you should always have a qualified professional to do your work.

Consider hiring a qualified home and structural pest inspector to review the home to ensure everything is safe and correct.

“If you think it's expensive to hire a professional to do the job, wait until you hire an amateur.”

Red Adair

If you find any errors or have additional information that would expand on any code, building standards or manufacturer requirements please let me know.

NCW Home Inspections, LLC  is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…  

Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service

Instructor- Fundamentals of Home Inspection-  Bellingham Technical College

WA Home Inspector Advisory Licensing Board

www.ncwhomeinspections.com                                                   509-670-9572

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