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Please note: Product availability and information are based on our research at time of writing and are subject to change. Always check Amazon for the latest details before purchasing. Our assessments are research-based. We compared manufacturer specification sheets, installation sheets, brochures, packaging photographs and official product pages, and we have not installed or run these valves ourselves. Air admittance valves are not accepted everywhere, so confirm with your local plumbing authority before you buy.

Introduction

Every drain needs air. When water runs out of a sink or a shower, it pulls on the air in the pipe behind it, and a vent lets replacement air in so the fixture drains smoothly and its trap keeps its water seal. An air admittance valve (AAV) is a one-way valve that opens to let air in when draining creates that suction and closes under its own weight the rest of the time, which keeps sewer gas out. Studor, one of the makers, says an AAV can be used as an alternative to extending certain vents through the roof or the wall to open air, which is why homeowners meet them in island sinks, remote bathrooms and remodels where running a vent pipe is hard.

This review covers five valves for sink and bathroom fixtures on a single floor, venting a horizontal drain branch of 1-1/2 to 2 inches. It does not cover venting for sewage ejector or sump pits, any pump application, multi-story stack design, chemical-waste systems or air plenums. For the traps themselves, our guides to the best P-trap kits and to cleaning a P-trap are the better place to start.

⚠️ Check Your Local Code First

Air admittance valves are not allowed in every jurisdiction. The model codes address them (Section 918 of the 2021 International Plumbing Code and Section P3114 of the 2021 International Residential Code), but each jurisdiction adopts a particular edition, may amend or restrict it, and its inspector decides what is accepted. Studor says plainly that code compliance varies by state and municipality, and Oatey says acceptance varies by jurisdiction and that some local codes prohibit AAVs.

Ask your building department or inspector whether an AAV is accepted for your fixture, before you buy one. None of the products below should be called code-compliant for your home until your local authority says so.

✏️ Our Take

If your local code accepts an AAV and you are venting a typical sink or bathroom group, the Studor Redi-Vent 20349 is the simplest documented starting point: Studor’s sheet names the item and states 20 DFU on a horizontal branch. We label it Best Overall as our research-based editorial judgment, not as the result of installing or running the valves. The Studor Mini-Vent 20341 shows the same size and the same small-pipe limits on its sheet, with a condensation-diverting feature as its documented difference. The Oatey Sure-Vent 39016 is the second-maker option. The Sioux Chief 696-11P is the one to consider when the valve must sit behind a wall in an access box, and the Studor AAV Tee 20391 is the tubular-adapter option, with its fit stated on the packaging only.

IN THIS GUIDE

Quick Comparison

Product and adapter Best for Branch rating Tier
Studor Redi-Vent 20349 BEST OVERALL
ABS, 1-1/2 or 2 in		 Sink and bathroom branches 20 DFU (Studor) $
Studor Mini-Vent 20341
PVC, 1-1/2 or 2 in		 Condensation feature 160 DFU, larger pipe (IPS)* $$
Oatey Sure-Vent 39016
PVC, 1-1/2 x 2 in		 Second maker 160 DFU, larger pipe (Oatey)* $
Sioux Chief 696-11P kit
PVC hub, 1-1/2 in		 In-wall access box 20 DFU (Sioux Chief) $$
Studor AAV Tee 20391
Tubular tee, per packaging		 Single fixture, tubular tee 20 DFU (packaging) $$

Branch ratings are each maker’s own figures (named in brackets), in DFU (drainage fixture units); do not compare them across makers or read them as the limit for your pipe. *The higher figures are valve ratings reached on larger pipe. The pipe-size tables that Studor, Oatey and Sioux Chief print each list 3 DFU at 1-1/2 in and 6 DFU at 2 in on a horizontal branch, so the higher figures add no small-branch capacity in this review’s scope (the makers’ tables cite different editions of the International Plumbing Code). Price tiers follow the site’s product-box rule, in which $ is under $20, $$ is $20 to $60 and $$$ is over $60; they match the product boxes below and can change.

Mini-Vent and Redi-Vent: What the Sheets Show

Studor sells both valves for the same pipe sizes, and homeowners often ask which one is the smaller. Studor’s own specification sheets print the same dimensions for both. Here is what each sheet and Studor’s pages state, side by side.

  Redi-Vent 20349 Mini-Vent 20341
Size on the sheet 2 in wide, 2-5/8 in high, 1-1/2 in NPT thread 2 in wide, 2-5/8 in high, 1-1/2 in NPT thread
Adapter fits 1-1/2 or 2 in pipe 1-1/2 or 2 in pipe
Branch limit, 1-1/2 in pipe 3 DFU 3 DFU
Branch limit, 2 in pipe 6 DFU 6 DFU
Branch limit, 3 in / 4 in pipe (background) 20 / 20 DFU 20 / 160 DFU
Valve rating as stated (background) Up to 20 DFU on a horizontal branch (sheet) Up to 160 DFU on a branch (IPS product page)
Adapter in this review ABS (PVC twin is item 20346) PVC (ABS twin is item 20340)
Feature named on the sheet Screening inside and out Screening inside and out; diverts condensation away from the sealing membrane

Studor’s product pages describe both valves, and the AAV Tee, as compact and suited to tight applications, but the printed dimensions match, so we do not treat either as the smaller valve. For a sink or bathroom branch of 1-1/2 or 2 in, Studor’s tables give the two valves the same limits. The differences are the Mini-Vent’s higher figures on 3 and 4 in pipe, which are background here, and the condensation-diverting feature on its sheet.

Full Reviews

1. Studor Redi-Vent 20349 Air Admittance Valve with ABS Adapter (1-1/2 or 2 in Pipe) — Best Overall

Best Overall

The Redi-Vent is Studor’s valve for single fixtures and small groups. The specification sheet that lists item 20349 describes an ABS valve with a silicone membrane, screening on the inside and outside to protect the seal, and an ABS or PVC adapter. The 20349 is the ABS-adapter version, and the same sheet lists a PVC-adapter twin as item 20346. Studor says the valve will vent up to 20 DFU on a horizontal branch, and its installation sheet (48105, REV 12/2015) says the valve is rated for single fixtures, kitchen sinks and bathroom groups, including back-to-back applications, up to 20 DFU.

Studor’s tables give the horizontal-branch limit by pipe size: 3 DFU at 1-1/2 in and 6 DFU at 2 in, the same figures it prints for the Mini-Vent, then 20 DFU at 3 in and at 4 in. The sheet lists 2 in wide by 2-5/8 in high with a 1-1/2 in NPT thread, and the adapter as fitting 1-1/2 or 2 in pipe. Studor names ASSE 1050 and 1051 (2009 editions) and NSF 14 on the sheet.

★ Top Pick

Studor

Studor Redi-Vent 20349 Air Admittance Valve (ABS Adapter, 1-1/2 or 2 in Pipe)

Best for: Sink and bathroom branches

In Stock

An air admittance valve from Studor with an ABS adapter that fits 1-1/2 or 2 in pipe.

Check Price

on Amazon · $

Pros and Cons ▾ tap to expand

Last updated: 2026-10-06

2. Studor Mini-Vent 20341 Air Admittance Valve with PVC Adapter (1-1/2 or 2 in Pipe) — Condensation-Diverting Feature

Condensation-Diverting Feature

On paper, the Mini-Vent is the Redi-Vent’s twin at the pipe sizes most sinks and bathroom groups use. Studor’s sheet for item 20341 shows the same 2 in by 2-5/8 in outline and 1-1/2 in NPT thread, the same adapter that fits 1-1/2 or 2 in pipe, and the same horizontal-branch limits at 1-1/2 in (3 DFU) and 2 in (6 DFU). Its documented difference in this review’s scope is a feature the sheet describes as diverting condensation away from the sealing membrane; the materials list also names polystyrene alongside the ABS valve and the ABS or PVC adapter. The 20341 is the PVC-adapter version, and the ABS-adapter twin is item 20340. Studor’s installation sheet is 404-1033 (REV 12/2015).

The larger-pipe figures are background only. The sheet’s table lists 20 and 160 DFU for 3 and 4 in branches (the Redi-Vent’s lists 20 and 20), and IPS’s page for the 20341 describes the valve as venting up to 160 DFU on a branch. Those figures apply to larger pipe. They provide no additional small-branch capacity at the 1-1/2 and 2 in sizes this review covers, where Studor’s table gives both valves the same limits.

Studor

Studor Mini-Vent 20341 Air Admittance Valve (PVC Adapter, 1-1/2 or 2 in Pipe)

Best for: Condensation-diverting feature

In Stock

Studor's Mini-Vent with a PVC adapter that fits 1-1/2 or 2 in pipe.

Check Price

on Amazon · $$

Pros and Cons ▾ tap to expand

Last updated: 2026-10-06

3. Oatey Sure-Vent 39016 Air Admittance Valve (1-1/2 x 2 in PVC Sch. 40 Adapter) — Second-Maker Option

Second-Maker Option

Oatey’s Sure-Vent 39016 is the second-maker alternative. Oatey’s technical specification (LCS1501c, 07/25) names item 39016 as a 160 DFU branch valve with a 1-1/2 by 2 in PVC Schedule 40 adapter, a silicone membrane and 2 in PVC NPT threads, and lists ASSE 1050 and 1051, ICC-ES ESR-1664, NSF 14 and an IAPMO classified mark. The sheet’s drawing gives 2.82 in across and 4.69 in overall with the 2 in hub adapter attached; Studor’s sheets do not say whether their 2-5/8 in height includes an adapter, so we do not compare the heights directly. Oatey’s brochure reprints the pipe-size table, citing the 2015 International Plumbing Code: 3 DFU at 1-1/2 in and 6 DFU at 2 in on a branch, so the 160 DFU figure is background here as well.

Oatey’s own literature carries the cautions. The sheet cites the 2003 editions of the IPC and IRC, so check what your jurisdiction has adopted now. The Amazon listing for this model includes a 20 DFU rating and a 3 in pipe size that do not match Oatey’s sheet for item 39016, so rely on the model number and Oatey’s sheet. Oatey says its valves are for indoor use and must stay accessible, and it lists ABS-adapter versions under other item numbers. Its installation text is in LCS1501c and brochure LCS420G; Oatey publishes no separate sheet online.

Oatey

Oatey Sure-Vent 39016 Air Admittance Valve (1-1/2 x 2 in PVC Sch. 40 Adapter)

Best for: A second maker

In Stock

A Sure-Vent from Oatey with a PVC Schedule 40 adapter for 1-1/2 and 2 in pipe.

Check Price

on Amazon · $

Pros and Cons ▾ tap to expand

Last updated: 2026-10-06

4. Sioux Chief 696-11P TurboVent Air Admittance Valve with OxBox Access Box Kit (1-1/2 in PVC Hub Adapter) — Best for Concealed Installation

Best for Concealed Installation

Sioux Chief’s 696-11P is the kit to look at when the valve has to sit behind a wall. Sioux Chief’s product page lists it as a TurboVent air admittance valve with a 1-1/2 in PVC Schedule 40 hub adapter and an OxBox kit, and the TurboVent brochure notes that the OxBox kits include the box, frame and louvered cover. The maker’s product photograph shows a box with a valve and hub adapter mounted inside, a plain frame and a louvered cover. Sioux Chief rates this 1-1/2 in model at 20 DFU on a branch, lists ASSE 1050 and 1051, and says the valve’s internal actuator spins with each opening to keep the sealing surface clean and that it seals against 13 psig of back pressure (the maker’s claim).

Sioux Chief links one instruction sheet on the 696-11P page, the 250 Series TurboVent instruction sheet (IS-250, 12/25). The sheet names no item numbers, and Sioux Chief does not publish part numbers for the parts inside the kit, so we do not say which stand-alone valve the kit contains. The sheet’s limits include access (it gives an access box, under a sink, an attic and a drop ceiling as examples) and installing the valve at least 4 in above the trap weir, whereas Studor and Oatey measure the 4 in from the horizontal branch drain or fixture drain, so read the wording for your valve and ask your inspector. Sioux Chief publishes no installation document for the box or the kit, and this review does not cover box installation.

Sioux Chief

Sioux Chief 696-11P TurboVent Air Admittance Valve with OxBox Access Box Kit (1-1/2 in PVC Hub Adapter)

Best for: Concealed, accessible installation

Limited Stock

Sioux Chief's TurboVent kit for a concealed installation: a 1-1/2 in PVC hub adapter and an OxBox kit that, per Sioux Chief, includes the box, frame and louvered cover.

Check Price

on Amazon · $$

Pros and Cons ▾ tap to expand

Last updated: 2026-10-06

5. Studor AAV Tee 20391 Redi-Vent Air Admittance Valve with Tubular Tee Adapter — Tubular Tee Option

Tubular Tee Option

The AAV Tee is a Redi-Vent valve packaged with a tubular tee adapter. The retail packaging, shown in photographs on the maker-sold Amazon listing, prints “MFG PART #20391”, “Rated up to 20 DFU” and “Fits 1 1/2″ and 1 1/4″ Drains”, and its back panel carries instructions headed “Redi-Vent Air Admittance Valve with Tubular Adapter Instructions” for model 20391. Studor’s specification sheet lists a polypropylene tubular adapter and an ABS valve with a silicone membrane and states up to 20 DFU on a horizontal branch, and IPS describes the product for a single fixture or a group of bathroom fixtures, designed to fit 1-1/2 in pipes. The fit wording in this review comes from the packaging.

Treat the connection details as unresolved. A review on the Amazon listing reports that the tee’s pipe end matched neither a 1-1/2 in nor a 1-1/4 in coupler, while other reviews report that it fit. We cannot verify either account, and no Studor document we found explains how the adapter connects, so we do not say what it will connect to. Studor’s public installation-instructions page covers other models; the instructions for this one are on the packaging.

⚠️ Check the fit before you order

The 1-1/2 in and 1-1/4 in statement is Studor’s, from the packaging, and one reviewer reports a mismatch. Compare the packaging statement with your own pipe, and ask Studor if you are unsure, before you rely on it.

Studor

Studor AAV Tee 20391 Redi-Vent Air Admittance Valve with Tubular Tee Adapter

Best for: Single fixtures or bathroom groups, tubular adapter

Limited Stock

A Redi-Vent valve packaged with a tubular tee adapter.

Check Price

on Amazon · $$

Pros and Cons ▾ tap to expand

Last updated: 2026-10-06

How to Choose an Air Admittance Valve

What an AAV Does, and What It Does Not

An AAV lets air into the drain system when draining creates suction. It does not relieve pressure that builds up in the drain: Studor says its valves must not be used to relieve back pressure, Oatey says its valves are not designed to relieve positive pressure, and Sioux Chief says an AAV shall not be used as a relief vent. The model codes still call for at least one stack vent or vent stack extending outdoors for each plumbing system (Section 918.7 of the 2021 IPC and Section P3114.7 of the 2021 IRC). An AAV is a way to avoid running a branch vent, not a replacement for the building’s main vent.

Read Ratings by Pipe Size

A valve’s headline rating and the limit for your pipe are different numbers. The makers print pipe-size tables that cite the International Plumbing Code: on a horizontal branch they list 3 DFU at 1-1/2 in and 6 DFU at 2 in, and the larger figures (20, 160) belong to 3 and 4 in pipe. Because the makers cite different editions of the code, do not compare ratings across makers. Have a licensed plumber confirm the fixture load, branch sizing and valve selection under your locally adopted code.

Match the Adapter to Your Pipe Material and Size

Each valve here comes with a specific adapter. The Studor Redi-Vent 20349 has an ABS adapter and the Mini-Vent 20341 a PVC adapter, each for 1-1/2 or 2 in pipe, and both makers sell the other material under other item numbers (20346 and 20340). The Oatey 39016 has a PVC Schedule 40 adapter for 1-1/2 and 2 in pipe, the Sioux Chief 696-11P a 1-1/2 in PVC hub adapter, and the AAV Tee 20391 a tubular tee adapter whose fit is stated on its packaging. Check the item number, the adapter material and your pipe before you order. Our guides to cast iron versus PVC drain pipe and PVC versus CPVC pipe explain how the pipe materials differ.

Location Limits the Makers State

This review does not give installation steps, but the location limits matter when you choose a valve. The makers state that the valve must stay accessible for inspection and replacement, have enough air around it, stand upright (within 15 degrees of vertical), stay indoors within the temperature range they print, and sit at least 4 in above the branch drain or fixture drain it vents (Sioux Chief words this as 4 in above the trap weir). Studor, Oatey and Sioux Chief also give 6 in above insulation for an attic. If the valve has to sit inside a wall, the access requirement is the reason the kit in this review exists; Studor’s manual says a valve inside a sink or vanity cabinet is acceptable. Ask your inspector what yours will accept.

What This Review Leaves Out

We left out venting for sewage ejector pits, sumps, tanks and any pump application. The model codes say an AAV is not to vent a sump or tank unless the vent system is designed by an engineer (Section 918.8 of the 2021 IPC and Section P3114.8 of the 2021 IRC), and the makers set their own conditions (Studor: engineer design and prior local-code approval; Oatey: local-code and pump-maker approval). If you are choosing an ejector pump, start with our review of sewage and effluent ejector pumps and talk to your pump’s maker and your inspector. We also left out valves for multi-story stacks, chemical-waste systems and supply or return air plenums, and the 2021 IPC lists plenums and non-neutralized special waste as prohibited uses.

Check the Exact Model, the Listing, the Seller and the Warranty

Listings can mix up models, adapter materials and ratings, so rely on the manufacturer’s model number and documents rather than a listing’s bullet points. The same item can be offered by several sellers, and an affiliate link cannot choose the seller, so check who is selling it and the return terms before you order. Studor states a limited lifetime warranty for replacement of defective valves on its sheets and pages. We state no warranty term for Oatey, whose documents describe it in different ways, or for Sioux Chief, whose terms we did not confirm, so read each maker’s current warranty.

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Frequently Asked Questions

Q: Does an AAV replace the vent through the roof?

No. The makers and the model codes still call for at least one vent extending outdoors for the building’s drainage system. An AAV can stand in for a branch vent where your code accepts it; it does not relieve pressure in the drain.

Q: Is the Mini-Vent smaller than the Redi-Vent?

Not on Studor’s sheets. Both list 2 in wide by 2-5/8 in high with a 1-1/2 in NPT thread, and the same limits at 1-1/2 and 2 in on a branch (3 and 6 DFU). The Mini-Vent’s documented difference is a feature that diverts condensation away from the sealing membrane; its higher figures apply on 3 and 4 in pipe.

Q: What do the DFU numbers mean?

DFU stands for drainage fixture unit, the load value the plumbing codes assign to a fixture. A valve’s rating and the limit for your pipe size are separate numbers; have a licensed plumber confirm the fixture load, branch sizing and valve selection under your locally adopted code.

Q: Can I use these valves on a sewage ejector pit or sump?

This review does not cover that. The model codes say an AAV is not to vent a sump or tank unless the vent system is designed by an engineer, and the makers set their own conditions (Studor: engineer design and prior local-code approval; Oatey: local-code and pump-maker approval). Talk to your inspector and your pump maker.

Conclusion

Start with your local code: if your jurisdiction does not accept an air admittance valve for your fixture, none of these picks is the right choice. If it does, the Studor Redi-Vent 20349 is the simplest documented starting point for a sink or bathroom group on 1-1/2 or 2 in pipe, and the Mini-Vent 20341 is the same size on Studor’s sheets with a condensation-diverting feature. The Oatey Sure-Vent 39016 gives you a second maker, the Sioux Chief 696-11P is the access-box kit for a concealed valve, and the Studor AAV Tee 20391 is the tubular-adapter option, with its fit stated on the packaging and one reported mismatch to weigh. Check the model, the adapter and your pipe, and have a licensed plumber confirm the sizing before you buy.

Manufacturer and Code Sources

The specifications in this review come from these manufacturer documents, pages and code texts:

✍️ About This Review

PTR Editorial Team — Product Reviews. We compare manufacturer specifications, installation requirements, compatibility and available product documentation to help homeowners choose suitable tools and parts. For this Review, the product specifications are sourced from manufacturer data sheets, installation sheets, brochures and official product pages, as noted above. How we review →

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