View Full Version : Vent pipe material
Jon mackay
01-30-2010, 09:45 AM
This vent was replaced as a repair to a defect I found.
I am second guessing myself on the pipe material, it does not appear to be all galvanized. Is it B-vent? It looked like the steel pipe that will rust out..
Also, is that duct taping allowed?
Scott Patterson
01-30-2010, 10:31 AM
It does not look like "B" vent. But, it does look like it is galvanized pipe.
The sections should have been screwed together.
The tape is wrong if that is all that is holding the pipe together.
I don't see any support strapping for the vent pipe.
Jon mackay
01-30-2010, 10:40 AM
OK, I was curious because I couldn't see the flakes on all of the pipes, just a section or two..
H.G. Watson, Sr.
01-30-2010, 01:39 PM
That water heater has a defective vent connection. That single wall elbow offset attached to the draft hood is wrong. There should be a vertical rise at least a foot above the draft hood before any offset.
A single wall vent connector is acceptable to transition to bvent but it must be done properly. Each appliance needs its own vent connector - which then ties into the bvent (if that's what you have).
It requires support as SP indicated.
Single wall requires clearance from combustibles. Not only is tape wrong but so is allowing remaining combustible price tags/upc tags.
I have no idea what "flakes" you refer to - perhaps you refer to the surface appearance of galvanized (zinc applied) steel?
The single wall should be an approved material for the med-heat appliance - it must be sufficient gauge and material - dryer vent is not sufficient.
What is the green appliance to the left sharing the same venting? What is its fuel?
Jerry Peck
01-30-2010, 04:14 PM
The connector also needs at least 1 foot rise before the elbow.
The connector and vent BOTH need to be supported properly.
These are in addition to all the information stated in the posts above.
Nat Palmer
02-01-2010, 12:29 PM
Does anyone have the reference for the one foot rise before an offset on the vent? I haven't been able to find anything outside of some manufacturers installation instructions.
Jon Errickson
02-01-2010, 12:34 PM
Just curious -- is the 1 foot measured from the water heater up, the base of the draft hood or the top of the draft hood? Thanks.
Wayne Carlisle
02-01-2010, 01:02 PM
Does anyone have the reference for the one foot rise before an offset on the vent? I haven't been able to find anything outside of some manufacturers installation instructions.
In the 2006 IFGC all connectors have a minimum of 1 foot
TABLE 504.3(1)
TYPE B DOUBLE-WALL VENT
VENT CONNECTOR CAPACITY
http://pic20.picturetrail.com/VOL148/1822929/21448713/382115433.jpg
Jerry Peck
02-01-2010, 06:50 PM
Just curious -- is the 1 foot measured from the water heater up, the base of the draft hood or the top of the draft hood? Thanks.
From where it sets on the draft hood to the bend, some measure from the draft hood bottom, not sure if there is a big difference in effectiveness between the two, but the connector rise minimum is 12" and the draft hood is not the "connector".
Jon Errickson
02-01-2010, 08:17 PM
Thanks Jerry.
Bob Harper
02-10-2010, 07:43 AM
All the vent sizing charts start at 12" rise but there is no single line in the code flat out stating you have to have that min so its up to interpretation by the AHJ. However, you would need to cross-reference each appliance mfrs. instructions.
The vent connector appears to not be screwed together at each joint--no foil tape.
The vent connector are not supported
The WH connector is undersized--see the charts in the code.
I don't see a cleanout in the chimney.
Can't tell for sure but might not have 6" clearance to that combustible sidewall.
Is this an enclosed mechanical room? If so, do you have requisite makeup air?
Would need to checl that connector to see if it is aluminun vs. galv. steel. If stainless steel, that's fine. You can exceed the code but never reduce it.
That's about all I can see from here.
A.D. Miller
02-10-2010, 08:09 AM
From: http://www.duravent.com/docs/instruct/L204A_July09.pdf
8. Connector Rise.
Plan a minimum of one foot vertical connector rise coming out of each appliance.
Jon Errickson
02-10-2010, 08:35 AM
Great document. Thanks AD!
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