HVAC Bonding

[rdcain]

A client has requested the the HVAC duct sections be bonded together and referenced the NEC. However I can't find an article in the NEC that addresses this. Does anyone know if there is an NEC article saying that the HVAC duct sections have to be bonded together? It makes sense because I can see how the moving air could create static electricity. Thanks.

 

[retirede]

Isn’t the ductwork electrically continuous back to the furnace which is grounded?

 

[infinity]

There is no NEC requirement to bond sections of metal duct together.

 

[rdcain]

Isn’t the ductwork electrically continuous back to the furnace which is grounded?

Supposedly it will be with the sections bolted together. But they've asked for bonding. Thanks

 

[rdcain]

There is no NEC requirement to bond sections of metal duct together.

Thanks for your response

 

[rdcain]

Thanks for your response

A quick clarification, how about across a flexible ventilation joint?

 

[augie47]

There is an Informational note in 250.104 that "suggests" bomding air ducts but it is NOT a Code requirement.

 

[rdcain]

There is an Informational note in 250.104 that "suggests" bomding air ducts but it is NOT a Code requirement.

Ok, thanks

 

[don_resqcapt19]

There is not a requirement to bond the metal ducts, but the Informational Note following 250.104(B) suggests that such bonding will improve safety.

Informational Note No. 1:
Bonding all piping and metal air ducts within the premises will provide additional safety.

 

[DrSparks]

Might be good to do also if you use motorized zone dampers.

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[rdcain]

There is not a requirement to bond the metal ducts, but the Informational Note following 250.104(B) suggests that such bonding will improve safety.

Thanks

 

[augie47]

We experienced a fatailty in our area where a damaged piece of romex came in contact with a heating duct in a crawl space and a maintenance worked contacted the duct.

 

[rdcain]

Might be good to do also if you use motorized zone dampers.

Sent from my SM-A326U using Tapatalk

Good point.

 

[Eddie702]

I did it 1 time when a DRYOTRON pool heater/dehumidifier and the ductwork fed the pool area