[KwartzLab] plenum vs non-plenum

[Darcy Casselman]

Sweet!  Thanks, Ben.  Yeah, I'll be there.

Darcy.

On Fri, Sep 7, 2012 at 11:16 AM, Ben Brown <ben at kwartzlab.ca> wrote:
> Hey are you gonna be at the party tonight? I found a box with about
> 180ft of Cat5e plenum if you want it.
>
> Ben
>
> On 9/5/2012 11:03 AM, Darcy Casselman wrote:
>> Sweet! I like free... :D
>>
>> On Wed, Sep 5, 2012 at 10:58 AM, Ben Brown <ben at kwartzlab.ca> wrote:
>>> I'll have a look, I may still have some plenum kicking around here you
>>> can have for free. I have cat5e as well, if you ever need some.
>>>
>>> Ben
>>>
>>> On 9/5/2012 10:49 AM, Darcy Casselman wrote:
>>>> Hm, that's not a bad idea.  There are a couple places I need to cross
>>>> over heading ducts, which gave the idea of fire-rated cable more
>>>> practical appeal.
>>>>
>>>> PrimeSpec looks like it only sells spools of 1000', which is way more
>>>> than I need.  And $185 is somewhat more than I want to pay.
>>>>
>>>> Darcy.
>>>>
>>>> On Wed, Sep 5, 2012 at 9:23 AM, Kevin Martin <kpmartin at thinkage.ca> wrote:
>>>>> Indeed the question is what is a plenum. The word (as far as building trades
>>>>> are concerned) originates in ventilation terminology, and applies to spaces
>>>>> such as that above a drop ceiling when it forms part of the ventilation
>>>>> system. In commercial buildings the space above the drop ceiling is often
>>>>> used as the air return to the HVAC unit. It also applies in residential work
>>>>> to the wall and floor cavities that form part of the cold air return on a
>>>>> forced air heating system.
>>>>>
>>>>> Wiring in such spaces which could generate plentiful smoke would be a safety
>>>>> concern because it could quickly get dispersed throughout the building.
>>>>>
>>>>> The Ontario Building Code defines: "Plenum means a chamber forming part of
>>>>> an air duct system."
>>>>> 9.34.1.5.  Wiring and Cables: (2)  "Where a concealed space in a floor or
>>>>> ceiling assembly is used as a plenum, electrical wiring and cables within
>>>>> the plenum shall conform to Sentence 3.6.4.3.(1)." Section 3.6.4.3 then goes
>>>>> into a long-winded description of the fire ratings of the materials that
>>>>> form the plenum itself as well as stuff like wiring that happens t run
>>>>> through a plenum.
>>>>>
>>>>> If the space above the drop ceiling is closed and not part of the HVAC
>>>>> system, it would not count as plenum space, any more that the sealed
>>>>> cavities within a wall between each pair of adjacent studs would.
>>>>> That being said I have never seen any special provision for regular power
>>>>> wiring when it passes through a wall cavity that happens to form part of the
>>>>> cold air return in a residential heating system, although it would seem to
>>>>> me that the same hazard would exist. This may just be a case of endemic lax
>>>>> application of regulations. Or perhaps this only occurs in walls, which are
>>>>> not covered by 9.34.1.5 (2).
>>>>>
>>>>> In any case if you only need a few short runs in true plenum space, you
>>>>> could enclose them in conduit (some of the provisions of 3.6.4.3(1) allow
>>>>> for this). This is essentially the solution used for power cables in plenum
>>>>> spaces, where one sees conduit and/or armoured ("BX") cable. This might be
>>>>> cheaper and/or simpler than buying all plenum cable or buying two types of
>>>>> cable and having to splice them.
>>>>>
>>>>> -Kevin Martin
>>>>>   the Papertrail Handmade Paper & Book Arts
>>>>>   New Dundee ON
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Discuss mailing list
>>>>> Discuss at kwartzlab.ca
>>>>> http://kwartzlab.ca/mailman/listinfo/discuss_kwartzlab.ca
>>>>>
>>>> _______________________________________________
>>>> Discuss mailing list
>>>> Discuss at kwartzlab.ca
>>>> http://kwartzlab.ca/mailman/listinfo/discuss_kwartzlab.ca
>>>
>>> _______________________________________________
>>> Discuss mailing list
>>> Discuss at kwartzlab.ca
>>> http://kwartzlab.ca/mailman/listinfo/discuss_kwartzlab.ca
>> _______________________________________________
>> Discuss mailing list
>> Discuss at kwartzlab.ca
>> http://kwartzlab.ca/mailman/listinfo/discuss_kwartzlab.ca
>
>
> _______________________________________________
> Discuss mailing list
> Discuss at kwartzlab.ca
> http://kwartzlab.ca/mailman/listinfo/discuss_kwartzlab.ca