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Discussion Forum

Junction box in cold air return?

CJH | Posted in Construction Techniques on April 25, 2005 06:44am

I’m trying to get a pantry and all of it’s electric out of my kitchen prior to a remodel.

The only issues remaining is one bunch of wires.

The wires come up through the cold air return. I went down in the basement to see if I could pull the wires through and get them in a junction box outside of the cold air return. I cannot as one of the wires is too short.

I’m trying to get an answer on code to see if I can mount the junction box in the cold air return where the romex originates from anyways. Unfortunately I live just outside of the nearest city and and am sort of in no-mans-land when it comes to getting answers.

Direct access to the junction box is not a problem as the cold air return grate is right where I’d need the junction box to go. Removal of the grate and access to the junction box would be easy.

Any ideas? Would this be a big no-no?

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  1. CPopejoy | Apr 25, 2005 07:05pm | #1

    Chris,

    That's a BIG NO-NO.

    The exisiting wiring is a clear Code violation, and always has been.

    Cables are allowed to pass through a duct, perpendicular to the long axis of the duct. And as far as I'm concerned, that's a poor design or a kludge.

    I'd suggest putting a j-box in the basement, and splicing in a long-enough run of new cable to reach where needed.

    Cliff

    1. CJH | Apr 25, 2005 07:24pm | #2

      Thanks for that information.My worst case scenario is leaving the existing wires where they are at in an island. It will restrict the possible kitchen layouts, which we don't like, but we can live with it."I'd suggest putting a j-box in the basement, and splicing in a long-enough run of new cable to reach where needed."The problem with this is that my shortest wire will not reach far enough anywhere in the plenum for me to run it out. If I pull down drywall and pull it out of the plenum then the rest of my wires don't reach to that point as they appear to enter the cold air return from a different direction.Does that make sense?

      1. DanH | Apr 25, 2005 07:43pm | #3

        You should remove ALL of the wires from the cold air duct. Add multiple junction boxes, then rewire as appropriate.Under the circumstances I might be tempted (if no other route can be found) to consider running a piece of STEEL conduit through the duct to contain the main connecting line between the various boxes (probably not 100% code, but it addresses the main safety issues), but you have difficulty doing this sort of thing without producing rattles.The main reasons for this code restriction:
        1) If a wire in the duct overheats and burns it will distribute noxious smoke throughout the house.
        2) In a fire the wire can serve as a source of combustable material in the duct, enabling the fire to spread more rapidly. Ductwork is often a major source of fire spread.
        3) Most heating ducts are thinwall steel (sharp edges) and prone to vibration. Where the wires enter/exit the duct, and where they lay against seams in the duct they're quite likely to wear through and short out to the duct. This can either cause a fire or, since ductwork is often isolated from ground by flexible vibration isolation sections, can make a section of the ductwork (including registers) "hot".
        4) As a practical matter, wire run any distance in ductwork is apt to make an annoying rattle.

      2. User avater
        BillHartmann | Apr 25, 2005 07:46pm | #4

        "The problem with this is that my shortest wire "Wire from where?If this is a kitchen over a basement then you should have fair access to do about anything in rewiring.But where does the power get to that area? Is that the problem.Forget the existing line and look at the "whole" and see what can be done.

        1. CJH | Apr 25, 2005 08:17pm | #5

          All I know is that the wires come up into the kitchen from the cold air return plenum.Where they go or come from beyond that is a mystery. At least to me so far.They appear to enter the plenum from different directions.

          1. DanH | Apr 25, 2005 09:14pm | #6

            If you want to do it right you're going to have to bite the bullet and knock out some plaster. Plaster's cheap.

          2. CJH | Apr 25, 2005 09:50pm | #8

            Sorry for the naive questions. This project started out as trying to get switches moved so we could turn a pantry into an island. With a bit of digging we figured out that we might be able to get rid of the pantry altogether, which we did not expect (a pleasant surprise). So I really did not plan on doing anything in the basement until late last night.I have since done a bit of measuring.The heat and cold air return ducts run parallel to each other below the floor joists. The romex that runs up into the kitchen is actually run through the floor joists that run perpendicular to the cold air return ducts. They are not in the duct themselves, but rather in the joist space that dumps into the cold air system.The peices of romex are between 24" and 28" away from the actual duct.So I guess the next question is when is a cold air return no longer a cold air return? Can I mount the junction box onto a floor joist that is 28" away from the cold air return duct? What if I move it farther away from the cold air return along the same joist? Is this entire joist space considered part of the cold air return system?

          3. User avater
            BillHartmann | Apr 25, 2005 10:13pm | #9

            All it has to be in NOT inside the "duct area". That would be any place that air moves through it when the fan is running.So if the duct is the area between two joist covered by sheet metal on the bottom then you could have wiring and juction box on the other side of that same joist.

          4. DanH | Apr 25, 2005 10:29pm | #10

            If you want to use the space beyond the last register, you should use sheet metal to effectively end the duct at that point.Once again, probably not 100% code, but if ONLY the junction box were in the cold air plenum, and if the wires entered through the back in such a way that they weren't exposed to plenum air and and also weren't exposed to sharp edges (ie, you have cable clamps threaded through holes in the duct), AND if the box used is reasonably "gas tight" (eg, weather-proof or explosion-proof box), then it would be safe to place the junction box in the plenum area, so that you could access the box via the cold air return register.But that would be something of a last resort.

          5. CPopejoy | Apr 25, 2005 11:35pm | #11

            Chris,Whatever you do, make sure it meets or exceeds the requirements of the NEC and any local amendments.If that means opening up a few holes in walls to replace cable runs so that j-boxes are accessible, do it.I assume that you and your family are or will be living in the house, and eventually someone else will be. The Code requirements are there for safety, i.e., for protection of human life against shock, electrocution, and fire resulting from inadequate installation of electrical wiring. Don't do something that'll save a little effort now, in return for a possible problem (or a tragedy) later.Do it right and you'll sleep better at night.Cliff

          6. CJH | Apr 25, 2005 11:57pm | #12

            Thanks. I was able to get an inspector on the phone and he was nice enough to swing over.He said to go ahead and pull the romex down into the joist-hollw and wire them in a J-box as far away from the return as possible. Then I should seal off that hollow from the romex the return. If it shut that flow off I can increase in somewhere else.I may actually be able to get all of the romex out of the return.

          7. DaneB | Apr 26, 2005 03:17am | #13

            Way to go Chris!!!

            Welcome to BT by the way.

            I hope that you learn and laugh as much as I have.

            Get some pictures of your kitchen while your working on it and after your done so we can see.  Think that almost everybody here loves seeing what others are doing and how they go about doing it.

            DaneI will always be a beginner as I am always learning.

          8. CJH | Apr 26, 2005 04:35am | #14

            Pictures are being taken. The project is really going well. We've moved switches to better positions and we have the pantry cut down to how we think we'd like an island. Even with drywall, 2x4's, and wires hanging everywhere it already gives us much more of that open floor plan we were looking for. I assume it would have been inappropriate to offer some cash to the inspector? His advice was very helpful, I'd gladly have paid for it. I imagine that's a no-no with a state inspector.Thanks for the welcome. This place came highly recommended.

          9. CPopejoy | Apr 26, 2005 06:04am | #15

            Buy him a cup of coffee.

            Write a letter to his supervisor, with emphasis on his professional and courteous approach, and technical expertise.  Steer clear of how he gave you advice on how to do wiring.  Most govt agencies don't want their people doing that.

            Waiting to see some pix.

            Cliff 

          10. 4Lorn1 | Apr 26, 2005 06:35am | #16

            Re: "Write a letter to his supervisor, with emphasis on his professional and courteous approach, and technical expertise."I thought he liked the guy. Inspectors and building departments don't often get nice letters. I'm pretty sure most of the letters they get are full of invective, threats, colorful descriptions of improbable lineage and inventive suggestions for the storage and filing of paperwork. Some of which is likely physically impossible. Sending a letter full of compliments could trigger heart attacks all round. Getting a genuine compliment could be quite a shock. If the DA is having a bad day he might be prosecuted for attempted murder.

          11. CPopejoy | Apr 26, 2005 06:43am | #17

            4lorn-

            Damn!  Didn't thnk of that! 

            Would that make me an accessory to murder?

            Cliff

          12. 4Lorn1 | Apr 26, 2005 07:23am | #19

            You may have started a whole new method for the disgruntled to attack government institutions: Drive-by complimenting.Next will be a national registry for loud hailers, bullhorns and megaphones.Once saw a photograph with GWB holding a megaphone. Does this mean he's a terrorist?When megaphones are outlawed only outlaws will have megaphones.Re: "Would that make me an accessory to murder?"Run and hide. The cattle mutilators, the MIB, and black helicopters are on the way.

          13. User avater
            JeffBuck | Apr 26, 2005 07:18am | #18

            "I'd gladly have paid for it. "

             

            U already have ... and will continue too ... forever!

            taxes.

             

            Jeff    

          14. DanH | Apr 26, 2005 04:31pm | #20

            Don't offer him money, or anything of "substantial value" (though coffee and donuts will almost certainly be appreciated). Most importantly, tell him to his face how much you appreciate his help. Or at the very least, write him a letter to that effect.However, I should point out here that your experience really isn't all that unusual. While most of the stories you hear about inspectors are horror stories of one sort or another, my experience has been that the folks in most building permit/inspection offices are really anxious to help the builder/sub/homeowner/whomever do the best job possible. But it's only the ignorant, nasty, or corrupt BIs that get the press.

          15. User avater
            JeffBuck | Apr 27, 2005 12:31am | #21

            U got an inspection scheduled for tomorrow, huh?

            the trick's gonna be .. how to make sure your inspector reads this tonight!

             

            Jeff    

          16. Stuart | Apr 27, 2005 02:43am | #22

            Not to take this off topic, but DanH - where are you located in SE Minnesota?  I noticed in one of your earlier posts you're in Olmsted county.  I'm originally from Chatfield, now living in Minneapolis.

          17. DanH | Apr 27, 2005 03:51am | #23

            Byron

          18. Stuart | Apr 27, 2005 03:55am | #24

            In that case, you're not the Dan H I thought you were, but still it's a small world.

          19. DanH | Apr 27, 2005 05:37am | #25

            Well, sorry to disappoint you.

          20. Frankie | Apr 25, 2005 09:41pm | #7

            My guess of what you have is a plenum composed of some sort of sheathing, nailed to the underside of two joists in the basement. If this is accurate, you could carefully unnail/ remove the sheathing, thus exposing the wires and either a) remove them back to the main panal and replace with new romex, or b) remove them from the two joists, reroute then through a gang box of the appropriate size, and run new extension from there.Afterwards, renail the sheathing or maybe even spring for new. As it is a return plenum. it doesn't require much skill or attention to detail.Frankie

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