Venting into soil pipe

[akist]

Have a toilet in the middle of the house with no way to vent outside. Saw on dragons den (YouTube) a fan pushing airflow at the top of the soil pipe behind the toilet. So I was thinking a vertical circuit with AAV then the fan then into the top of the soil pipe behind the toilet.

Has anyone done this and will it also help take away humid air from the shower?

 

[Wayners]

Winter just run a dehumidifier for 4 hours at the end of the day.
Dry washing with a dehumidifier in a room.
Lower the amount of moisture you create in the air if you have damp.

Re shower.
Don't know if you can use the soil pipe to vent air with fan. Difficult problem

 

[Madrab]

Can't say it's a standard approach no. is it acceptable as far as building regs are concerned, seems so as it extracts more than the required volume to meet the standard. Can't see any issue with it using the soil pipe as a vent either. It does need an external power source for the transformer. Also there doesn't seem to anywhere you can buy it, apart form an Australian PanFan system and that needs a separate pipe running externally

A 'vertical circuit', not sure what you mean by that? You would need to have a vent pipe connected to the toilet soil pipe that vents up and out to atmosphere, that's the only way that a fan at the back of a toilet like that could vent and work properly. if you put an AAV on that vent then it wouldn't errr, vent.

 

[akist]

I did not describe it properly.

My idea is to build a "box" inside which there is an AAV (durgo valve) (one way valve pulling air from the room but not allowing air to go into the room), then a "strong" fan, and then a pipe of some diameter which is connected to the soil pipe at the back of the toilet pan (at the top of course).

AAV, fan and pipe are sitting higher than then soil pipe so there is no possibility of foul water reaching the fan.

Expelled air will travel through the soil pipes until it escapes, typically through the nearest vertical soil vert pipe or through the sewers.

The problems that I see here, without having run a test, is how much air pressure may be inside the soil pipes that the fan must overcome. And another potential problem, if the fan would be too strong, would that interact with the various water traps (shower, sinks etc).

I do not think there will be a problem though, because if there were a lot of pressure inside the soil pipes system, you'd know about it every time you'd use your sink/shower etc and the solution is to vent sink/shower etc wastes. We had this problem here at my current house, where they plumbed utility and kitchen sink straight into the sewers, and that resulted in bad smells entering the kitchen, and I fixed it in two minutes by venting the sink waste just before it descended into the sewers.

Will building control accept it though?

 

[Madrab]

Expelled air will travel through the soil pipes until it escapes, typically through the nearest vertical soil vert pipe or through the sewers.

That's where it falls 'foul', excuse the pun. BC wouldn't have it I don't think but never say never, can always ask.

The problem I would see they may have is venting a room into the sewer with a forced air system and then hope it vents somewhere else. You would probably have to have your soil pipe with a dry section that vents vertically up to the atmosphere, therefore keeping your solution within your property. Using the sewer could potentially cause a positive pressure in the main drains pushing sewer gases into places it shouldn't be.

 

[akist]

Ahh, I already have 3 soil vent pipes around the house.

I will not ask my BC man. I will leave it as is, and if he spots it during final inspection, then we cross that bridge.

 

[Murdochcat]

Ahh, I already have 3 soil vent pipes around the house.

I will not ask my BC man. I will leave it as is, and if he spots it during final inspection, then we cross that bridge.

So you are planning on deliberately not complying with building regs ?

 

[akist]

Is venting through the soil pipes not complying with regulations? In this thread, up to now, it is being debated. Unless you know for sure?

 

[Murdochcat]

Is venting through the soil pipes not complying with regulations? In this thread, up to now, it is being debated. Unless you know for sure?

Best person to ask is your BCO …..

 

[Madrab]

Ahh, I already have 3 soil vent pipes around the house.

The one that the fan will be blowing into would need to have a vent to atmosphere, any venting down the soil pipe into the drains and then up another soil vent pipe wouldn't be right, a drain system is not designed to do that, especially if it is shared. Could cause unforeseen and unexpected issues.

You don't need to ask your own BC officer, just make a call to building control as someone else, if that's a concern.

 

[dilalio]

And fan needs to have some sort of one way valve else odours could be pushed back through it into the room when there is positive pressure in the sewer.

 

[JohnD]

what is above this room?

 

[akist]

Thinking aloud:

Above this bathroom there is a staircase and bedrooms upstairs (in the loft space). I could run a vertical, rectangular vent pipe to the roof through the floor and a bedroom upstairs. I would box it in, and it would be adjacent to a partition wall. Aside of the trouble of cutting a hole in the roof, and the potential roof leaks it will then cause. I will also have a boxed vent on a wall inside the room - an ugly feature. Can't go inside the partition wall (noggins and radiator pipes) so it will need to be adjacent. And there will be condensation running down the vent pipe too.

 

[JohnD]

Which way do the joists above run?

 

[Murdochcat]

And the longer the vent run, the more powerful fan you WILL require.