jar546
CBO
Can ENT, aka "Smurf" be used in an attic where you live? ENT (Electrical Nonmetallic Tubing) is typically blue or gray but can be other colors.
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ENT Smurf in Attics
- Thread starter jar546
- Start date
jar546
CBO
jar546
CBO
One of the limited factors is the ambient temperature of the attic. According to the NEC 362.12(3):
(3) Where subject to ambient temperatures in excess of 50°C
(122°F) unless listed otherwise
Then, upon looking at the specifications from Carlon, one or the largest producers of ENT I found this:
• ENT ambient temperature range -4 deg F (installation) to 122 deg F
So the question then becomes: How do you determine attic ambient temperature? Ambient temperature is not an average temperature, it is the highest actual temperature at a given moment. Attic temperatures in Minnesota, for example have been recorded at over 150F on a summer day. With that being said, factors such as type of attic ventilation and color of roof does have an affect on attic ambient temperature. Soffit and ridge vent systems have a lower attic temperature than soffit vents alone and a tile roof has a much lower attic ambient temperature than asphalt shingles.
In my opinion (yours may vary) I cannot see ENT (Smurf Tube) being code compliant if installed in an attic space unless the tubing is listed and labeled for higher temperatures. I would, however, not have any issues with ENT in a non-vented attic where the underside of the roof sheathing was insulated and the thermal envelope. At that point, the attic space itself is inside the thermal envelope.
Thoughts?
(3) Where subject to ambient temperatures in excess of 50°C
(122°F) unless listed otherwise
Then, upon looking at the specifications from Carlon, one or the largest producers of ENT I found this:
• ENT ambient temperature range -4 deg F (installation) to 122 deg F
So the question then becomes: How do you determine attic ambient temperature? Ambient temperature is not an average temperature, it is the highest actual temperature at a given moment. Attic temperatures in Minnesota, for example have been recorded at over 150F on a summer day. With that being said, factors such as type of attic ventilation and color of roof does have an affect on attic ambient temperature. Soffit and ridge vent systems have a lower attic temperature than soffit vents alone and a tile roof has a much lower attic ambient temperature than asphalt shingles.
In my opinion (yours may vary) I cannot see ENT (Smurf Tube) being code compliant if installed in an attic space unless the tubing is listed and labeled for higher temperatures. I would, however, not have any issues with ENT in a non-vented attic where the underside of the roof sheathing was insulated and the thermal envelope. At that point, the attic space itself is inside the thermal envelope.
Thoughts?
Gregg Harris
SAWHORSE
What if the house has more than three stories?
What if the attic is exposed to sunlight?
What if it is installed in an attic and exposed to foot traffic where damage could occur ?
What if the attic is exposed to sunlight?
What if it is installed in an attic and exposed to foot traffic where damage could occur ?
mtlogcabin
SAWHORSE
• Storage -4°F to 158°F• Handling -4°F to 104°F
FeaturesApproved Uses:Typical Applications:• Concrete slab – NEC Article 362• Walls - wood stud, masonry and metal stud – NEC Article 362.• Ceilings - permanent or dropped (free air only) – NEC Article 362.• Exposed – NEC Article 362• Public Assembly – NEC Section 518.4, in nonfire rated and certain five rated structures• Prewired – NEC Article 362• Classified by UL 1479 for Through Penetration Firestop Systems in UL Guide Category XHEZ and currentUL Fire Resistance Directory• Three hour rated floor/ceiling assemble• Raised Floors – NEC Section 645.5(D)(2)• Exposed or concealed in building above three floors when a fire sprinkler system is installed in accordance withNFPA 13 – NEC Section 362.10(2)• For use in residential attics up to 3 feet above the bottom of the ceiling joist.
steveray
SAWHORSE
Against the inside of the envelope you Shirley could use normal indoor range, halfway through gets dicey....
The 122F degree limit pretty much kills it.
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