External AAV Question

[DIYhiroshima]

Hi guys,

I have read on here a couple of threads about External AAV's, I found the "New" FloPlast External AAV Product and found that it complies to the regs etc and can be fitted as internal AAV i.e 200mm minimum above
the highest wet entry point etc but I have a question...

As I'm sure you have guessed I am not shall we say DIY savvy but my understanding is that an AAV only allows air IN... this would allow me to flush etc without siphoning of the traps. The fact that the AAV doesn't allow gas out would also mean that it would prevent smells... BUT and here's my question... If you do not let the gas OUT (vent) then where will they go?

I'll share my issue and see what you think...

I have a single soil stack with an open vent, this unfortunatley sits right below my bathroom window rather than extending the minimum 900mm above, It was like this when I bought the house and just another problem thanks to Jack... Now obvioulsy this results in some smells and I want rid.

Now I could go out and buy all the tools and pipes etc I need to extend it beyond my window but it would be much more labour and cost effective if the external AAV idea would work... If I fit the external AAV what will happen to all the gases that build up in the pipe, will they get sucked away when water flows?

Cheers for your thoughts...

 

[adlplumbing]

they open up when water moves thus changing the internal presure of the pipe which allows the air in so waste can be carried away when then process is complete then pressure changes back and seal shuts and keeps smells lockled away
that my understanding of it but some one may disagree
but also school thought that fairys make them and they work by magic

 

[TicklyT]

AAVs should not be used to replace the only open vent of a drain as they do not relieve positive pressures.

AAVs are intended for secondary stacks and stub stacks connected to a drain, but the stack at the 'head' of a drain should still be equipped with an open vent.

 

[BournemouthPlumber]

I know its always said that AAV's only fitted where system is vented elsewhere - but just reading through polypipe website and they say the following....

1. For up to and including four dwellings, one, two or three storeys in height, additional drain venting is not required. 2. For five to 10 dwellings, a conventional vent stack should be provided at the head of the drain run. 3. For eleven to 20 dwellings, a conventional vent stack should be provided at the mid-point and head of the drain run.
4. For multi-storey domestic dwellings (other than those referred to above) and non domestic buildings, conventional drain venting should be provided if more than one such building, each equipped with the valves, is connected to either a common drain, itself not vented by means of a ventilation stack, or to a discharge stack not fitted with a valve.

Any comments?

 

[BournemouthPlumber]

P.s. I am aware that it is a very sad thing to be doing on a Tuesday evening

 

[DIYhiroshima]

Well my house is a mid terrace, most of the houses on my line have vents... so does this mean that I could use the external AAV as the positive pressure would be discharged via one of the other vents along the line?

 

[adlplumbing]

just make sure manufactures say it stuable for out doors some are not due uv protection