An AAV should be located within the maximum developed length permitted for the vent. It must be located a minimum of 4” above the horizontal branch drain, 6” above any insulation material and within 15 degrees of vertical.
Individual and branch-type air admittance valves shall vent only fixtures that are on the same floor level and connect to a horizontal branch drain. Individual and branch air admittance valves shall be located not less than 4 inches (102 mm) above the horizontal branch drain or fixture drain being vented.
AAV vector genomes are been limited to 4.7 kb in length in order to balance the need for larger genetic constructs and effective payload delivery. Larger constructs can be attempted to be packaged in AAV vectors, however they are unlikely to be transfected and packaged enough to deliver the intended result.
Available in different sizes, AAVs can be used to vent an individual fixture, a complete branch, or an entire stack of vents.
The main problem with using an Air Admittance Valve instead of a Soil Vent Pipe, as discussed earlier, is that by preventing the gases from escaping through the top of the soil stack you are causing them to be forced down into the main drains and sewer system instead.
While this is rare, it is possible. Remember that these valves should last anywhere from 20 to 30 years, so if they are only lasting for a couple of years, there may be some problems that need addressing.
The AAV should be located: Within the maximum developed length permitted for the vent. A minimum of 4 inches above the horizontal branch drain.
Air admittance valves are typically placed between the P-trap of a fixture and the drain line. They're usually mounted on one leg of a sanitary tee, with the other leg going to the drain. The unit must be placed per local codes and the manufacturer's instructions.
Can my toilet and sink share the same vent? Yes, the toilet and sink can share the same vent, as can the shower.
To fulfill the local exhaust airflow requirements of ASHRAE 62.2 (2010) and the International Residential Code (IRC 2021, Section M1507), bathroom fans should have a mechanical exhaust capacity of ≥ 50 cfm for intermittent operation or ≥ 20 cfm of ventilation when operated continuously.
Limitations include the occurrence of immune-mediated toxicities, the potential loss of correction in the long run, and the development of neutralizing antibodies against AAV vectors preventing re-administration.
How long does an AAV last? Adeno-associated viruses (AAVs) are stable for several months to years when stored properly at -80°C.
AAV location
It must be located a minimum of 4” above the horizontal branch drain, 6” above any insulation material and within 15 degrees of vertical. AAVs cannot be permanently covered and should be installed in an area that allows air to enter the valve.
Some state and local building departments prohibit Studer vents. check with the local AHJ (Authority Having Jurisdiction) for more information. Studer vents are certified to reliably. However, anything mechanical can and will fail.
Yes. Any AAV can malfunction or not operate properly because it is a mechanical device. Signs of that the Sure-Vent is not operating as intended, are foul odors.
AAVs shall be accessible, should replacement be required. Such valves shall be installed in a location that allows air to enter the valve. Locating the valve in a sink or vanity cabinet is accessible. For in wall installation, use a recess box/grill combination or access grill.
A horizontal wet vent could have as few as two fixtures or as many as ten fixtures but not more than two fixtures of any type can be connected to the system.
Exhaust fans in separate dwelling units can share a common exhaust if each exhaust fan is equipped with a back-draft damper to prevent cross contamination. Remember to remove any packing tape used to hold the dampers closed during shipping.
The AAV is a one-way air valve which opens to allow air to flow into the system and balance the pressure. Once balanced, the valve will then close and create an airtight seal stopping any odours entering the building. By only opening one-way, the open valve draws in clean air, but stops any foul air escaping.
Air admittance valves often feature rubber seals, to help create a complete seal, increasing the effectiveness of the valve and preventing any odours from escaping through small gaps.
AAV may be transmitted through direct contact with an infected individual or through indirect contact with the contaminated environment. Transmission routes include respiratory, gastrointestinal and possibly sexual transmission. A concern for vertical transmission from mother to fetus also exists.
Air admittance valves are not permitted in spaces where pressure conditions adversely affect the valve's operation. They are also not allowed in concealed wall and ceiling spaces used as plenums as part of an air distribution system that is under negative or positive pressure.
The external soil stack may be terminated below the roofline which reduces the amount of soil pipe and fittings required. The AAV may be installed at a minimum height of 200mm above the highest wet branch connection.
AAV Virus Handling & Storage
All viral vectors are shipped frozen on dry ice and should be stored at -80° C upon receipt and for long term storage. Vectors can be stored for short periods of time at -20 or +4°C.