to all,
I seem to remember seeing a recent review/article about attic plumbing vent caps that can now be used. Did I see it in FHB, or was I dreaming? If in FHB what issue was it? I started looking in recent issues, but thought I would try here.
thanks,
jim
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"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
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It's in the new issue of FHB- they're called Air Admittance Valves.
Bob
thanks Bob
The AAV's weren't for attics, they were for places like kitchen islands & such where traditional venting is difficult.
The article stated that in order for them to work proplerly, it still needed to connect to a vented DVW line.
Not everyplace in the country allows them to be used, so check your local codes.
A leader in the Democratic Party is a boss, in the Republican Party he is a leader. [Harry Truman]
Are they similiar to studor (sp) valve?-----------------------------------------------------------------------------
WWPD
I assmed he was talking about studor vents. If not, I have no idea what else he might be referring to.
Do medics in Rome refer to IVs as 4s?
Studor is a brand name.Air admitance valve is the generic name for that like of product.
Our inspector allow them for special cases - island sinks, log houses and such - otherwise they are a no no. Why? I guess some are unreliable?
Treat every person you meet like you will know them the rest of your life - you just might!
First check local codes is a start. Second no matter what you still need a vent to atmosphere that is equal in cross sectional area to the drain going out. These air admittance caps ie studor vents are a mechanical check vale and all mechanical things eventually fail. I am opposed to them but I have installed them when no other way was practical. Main problem is they let air in ( to keep traps from siphoning) but they don't let air out so pressure gain is possible and in extreme conditions you have what is called the boiling toilet effect, which is gases coming through the trap not a "big" deal but is a nuisance.
Jim in my estimation they are a quick fix or for very special location. Beward what up the drain line. I installed one under our sink on a quick reno but I have a laundry washer up the line...everytime it drains the sink boils. I'm doing the walls shortly in the kitchen and will be putting a correct through-the-roof vent when that happens.
Byron
I have a similar problem, my sink burps. I put a check valve just upstream of the laundry wye. I believe it is just surface tension/friction with the laundry foam discharge and does not really hurt anything. There is never any sewer gas problem and the trap at the sink never empties. I have thought about changing the sink trap to 2". There is a 2" vent from the laundry to the main stack which is about twenty feet downstream of the sink with the aav (Studor brand) .
I had a house in Georgia that had a similar long run from the laundry but it was cast iron instead of PVC. I was concerned that I had a problem when I saw soapsuds on the roof, checked the line and no restrictions.
Edited 9/26/2005 8:13 pm ET by rasconc