Thread: AAV

Does this AAV have to be 4 inches higher than the bottom of sink, drain or trap? The picture I have in Code Check isn't clear. Thanks

It should be above the flood rim of the sink.

I read that in another post (above flood rim) but as you know it is impossible. That being the fact why do we see them installed this way?

Because no one bothered to read the instructions.

Excuse me, but I don't necessarily agree with the prior poster. Distance above trap and from trap more relevant usually, not flood rim. Perhaps thinking of air gap?

I can't see enough to identify with certantity the exact model of the device, if you have done so, please do share it with the rest of us Mr. Wand, thank you.

However, it appears far beyond the tolerance for a vertical install.

Most importantly, we cannot see a trap, the branch arm, nothing. We also don't know the elevation relationship to the building sewer and stack vent, floor drains, etc.. Flood rim of fixture does not necessarily apply.

What does your area use for plumbing, is this residential, or manufactured home? IRC, IPC based plumbing chapters, or UPC based?

Due to difficulties viewing photo as presented, cropped or limited view (and zero photo-shop type skills on this end regarding altering resolution, contrast, etc.) won't go further.

HG.

The code up here specifically states above flood rim.

Also see my posts regarding AAV at http://www.inspectionnews.net/home_i...you-think.html

7.5.9.2. Air Admittance Valves
(1) Air admittance valves shall only be used to vent,
(a) fixtures in buildings undergoing renovation, and
(b) installations where connection to a vent may not be practical.
(2) The air admittance valves shall be located,
(a) above the flood level rim of the fixture it serves,
(b) within the maximum developed length permitted for the vent,
(c) not less than 150 mm above insulation materials, and
(d) installed in a location not subject to back pressure.
(3) Air admittance valves shall,
(a) only vent fixtures located on the same storey, and
(b) be connected to the horizontal fixture drain.
7.5.9.3. Installation Conditions
(1) Air admittance valves shall not be installed in supply or return air plenums, or in locations where they may be exposed to freezing temperatures.
(2) Air admittance valves shall be installed in accordance with the manufacturer’s installation instructions.
(3) Air admittance valves shall be rated for the size of vent pipe to which they are connected.
(4) Installed air admittance valves shall be,
(a) accessible, and
(b) located in a space that allows air to enter the valve.
(5) Every drainage system shall have one vent that terminates to open air in conformance with Sentence 7.5.6.2.(1).

Originally Posted by Raymond Wand

HG.

The code up here specifically states above flood rim.

Well now that's interesting, as I thought I read you indicated the INSTRUCTIONS had not been read, implying it had something to do with the manufacturer's instructions/standards, approvals, not that it had something to do with your own Provincial or local codes. (Although I suspect you may not be entirely correct in your most recent assertion, I don't wish to engage in additional OFF TOPIC discussion on YOUR LOCAL Codes/rules in Ontario, Canada).

As T.R. indicates his location is in Utah, I would submit your local rules in Ontario may not apply.

Hey TR, whats that you're quoting, citing?

Appears to be something you've snipped from a Raymond Wand post supposedly quoting (Snipping) ONTARIO CANADA building code, which I doubt as to its completeness or accuracy, as there are skipped qualifying references and exceptions.

However, his earlier assertions as to the functioning of an AAV device are inaccurate, the graphics he posted are NOT supportive of his assertions, NOR are they indicative of an AAV (island loop venting), and....

The rules, whatever they may be, in the Province of Ontario, Canada, further restricted by the locality, are of no consequence to installations in Utah, I guarantee you that.

Originally Posted by Raymond Wand

HG.

The code up here specifically states above flood rim.

Also see my posts regarding AAV at http://www.inspectionnews.net/home_i...you-think.html

Raymond I have looked at that topic and your contributions there.

Your first post claiming that an AAV can not work properly unless above flood level rim is patently FALSE. The diagram you posted was of an island loop vent - which has NOTHING to do with an AAV.

An AAV can and WILL function when mounted above the horizontal drain. Code and mfgs require a distance ABOVE that drain so as to prevent contamination of the device and back-flow/fouling of the device and to assure functioning so as to avoid a slug or temporary vacuum (i.e. the dreaded drainage "burp").

HG

That diagram is in regards to the discussion about island sink venting, and not to do with AAV.

My apologies for posting contradictory info, I trust you can find it in your heart to forgive me for erroneous information and infringing on your knowledge base.

After some more searching it looks like the AAV should be 4 inches above the top of the trap. Sound right?

That looks like a mechanical vent and not an AAV. MV's are not approved for use in residental homes, only in manufactured homes. It needs to be an AAV....

I belive that the AAV should be 4" above the weir.

Originally Posted by Scott Patterson

That looks like a mechanical vent and not an AAV. MV's are not approved for use in residental homes, only in manufactured homes. It needs to be an AAV....

I belive that the AAV should be 4" above the weir.

Scott is correct on both accounts.

Also, it needs to be within 15 degrees of vertical and that looks to be an 1/8 bend coming up from the bottom, and then a 1/16 bend back, meaning that it is 1/16 bend off vertical. A 1/4 bend is 90 degrees, a 1/8 bend is 45 degrees, a 1/16 bend is 22-1/2 degrees, which means it exceeds 15 degrees off vertical.

I admit I suspected it might actually a mechanical vent myself, but was hopeful another photo or someone with photoshop type skills might enhance photo so might be better seen/identified, and plumbing path known; (hence the question if might be a manufactured home) before I stuck my proverbial foot in mouth. By the way MVs are legal to be on RVs as well. I thought I detected a clamp and some sort of set screw also, and was also suspicious of an abs fill cap port being used as a clean out. I just can't make out with the contrast all that black on black. Guess I'm going to have to learn the photo editing software and figure out how to hold multiple keys down at the same time with one not-so-dexterious hand.

Always instal these AAV "as per maufacturer's speicfications and reccomendations"...and you should be ok.

As long as the AAV can "breathe" I don't see the "above flood level rim" rule applying.