clearfox Eating worm monster arrived

[ProDave]

3 minutes ago, Hastings said:

£4650+VAT for the 8pe Clearfox.

The USP of no electricity is lost there.  My Conder was under £2K  The £2650 saved will pay for the electricity it uses for the rest of my life.

[Hastings]

I lived for years (until mains drains came to the street) very close to a Biodisc Klargester we shared with another house. It had no dedicated air vent, so it received enough oxygen via the outlet pipe to the stream and inlet pipe from the 2 houses it served, and it never smelled. Therefore I am puzzled as to why any treatment unit should need a vent at all.

 

My unit will be in a very windy exposed spot in the Hebrides where lack of enough oxygen entering the tank will not be an issue.

[Hastings]

10 hours ago, JSHarris said:

 

We have a Biopure unit, with an air blower..... There's no smell at all from it that I've been able to detect.  We have no vents on the foul drain that runs down to it, just the vent on the top of the lid.

 

But is there not a vent stack pipe at roof level at the house that allows air into or out of it?

[scottishjohn]

ouch--air pump i think 

[readiescards]

7 hours ago, Hastings said:

£4650+VAT for the 8pe Clearfox.

Plus I bet nearly another £500 installing it. It needs a big hole and lots of gravel. Or less gravel if you prefer to dig two smaller holes.

 

To be clear there is only a very slight aroma (a sweet smell) from the actual Clearfox vent pipe of you stick your nose within about an inch of it. And the output is a nearly clear liquid which is also pretty odourless.

 

The more unpleasant odour seems to come from the sludge collection tank. Yet I can't identify where. My nose seems to adapt to the smell after a few sniffs making identifying the source hard in a nearly always breezy site.

 

At the time of installation I was planning to live off-grid hence zero electric consumption was very important

[Jeremy Harris]

12 hours ago, Hastings said:

 

But is there not a vent stack pipe at roof level at the house that allows air into or out of it?

 

 

No, no vent stack at all, as it's a passive house, so adding one would have created a big thermal bridge.  Instead we have an internal air admittance valve on top of the internal soil pipe stack, that opens and draws a tiny amount of air in from the loft space if there is ever a partial vacuum in the pipes cause by a toilet flushing.

[Ed Davies]

5 hours ago, readiescards said:

At the time of installation I was planning to live off-grid hence zero electric consumption was very important

 

Winter-time off-grid electricity costs around £30/watt, maybe a bit more. IIRC, the Biopure uses 50 W even if you get the non-low-energy version and run it all the time so that's something like £1500 to £2000 extra. I'd rather spend that extra money on more PV than on a passive treatment plant as it'll give me spare power for the other ¾ of the year.

 

1 hour ago, JSHarris said:

No, no vent stack at all, as it's a passive house, so adding one would have created a big thermal bridge.  Instead we have an internal air admittance valve on top of the internal soil pipe stack, that opens and draws a tiny amount of air in from the loft space if there is ever a partial vacuum in the pipes cause by a toilet flushing. 

 

That's what I'm planning, too: Biopure, AAV in loft, only vent on the treatment plant. Useful to know it works OK. Thanks.

[joe90]

I have a stack but it’s not on the house but on the rear of the garage past the house ( garage has a toilet). I thought it a good idea just to get more air into the external pipework .

[Hastings]

23 hours ago, JSHarris said:

 

 

No, no vent stack at all, as it's a passive house, so adding one would have created a big thermal bridge.  Instead we have an internal air admittance valve on top of the internal soil pipe stack, that opens and draws a tiny amount of air in from the loft space if there is ever a partial vacuum in the pipes cause by a toilet flushing.

 

That sounds ideal for my airtight low energy renovation. But my architect says I need a vent stack pipe at roof level on the longest run (of foul drain pipe) plus AAV in every room connected. Could that be wrong? He doesn't know the regs 100% and the foul drainage has not been passed by BC yet as the warrant (Scotland) passed is for a waterless closet (now abandoned).

 

Is your loft AAV positioned outside the thermal envelope? Do you also have AAV in every room connected?

[Jeremy Harris]

2 hours ago, Hastings said:

 

That sounds ideal for my airtight low energy renovation. But my architect says I need a vent stack pipe at roof level on the longest run (of foul drain pipe) plus AAV in every room connected. Could that be wrong? He doesn't know the regs 100% and the foul drainage has not been passed by BC yet as the warrant (Scotland) passed is for a waterless closet (now abandoned).

 

Is your loft AAV positioned outside the thermal envelope? Do you also have AAV in every room connected?

 

 

Your architect is wrong, I'm afraid.

 

I double checked this with building control and have it in writing that in order to comply with the building regs all that is needed is a form of external vent to the foul drain (just one) plus a means of allowing air into any vertical soil drain stack via an air admittance valve, or valves, if there is more than one soil pipe stack in the house).

 

We have a single vertical soil pipe stack inside the house, and this extends up into the eaves space and is fitted with a 110mm air admittance valve at the top, inside the heated envelope of the house.  This is the drawing I sent to building control in order to get approval for this:

 

Elevation - Section showing foul drain stack - A4.pdf

 

Building control agreed with me that the treatment plant vent was an adequate means of ventilating the whole foul drain run to atmosphere.

[Hastings]

I have just one toilet, on ground floor in lean-to extension. No basins etc upstairs.

So if treatment plant has a vent on it then just one AAV in the WC/shower room ground floor is all I need? No need for any "roof level..." or in-loft vent?

[ProDave]

This vent stack thing does seem very open to interpretation by building control.

 

I argued that the drain run was vented at the far end by a vent stack on the static caravan so we did not need one on the house and a AAV was all we needed.  Our BC inspector argued that someone might remove that later and we had to have a vent stack on the house.

 

He would have accepted just a vent pipe going up the end of the house and joining into the drain beyond the house, and then AAV's in the house, but by that point I had concreted the car parking area so had missed the chance to bury a pipe for that, so I did end up fitting a vent stack out of the top of the roof.  I can't say I notice it being particularly cold to touch, but I will insulate around it before boxing it in.,

[scottishjohn]

1 hour ago, Hastings said:

I have just one toilet, on ground floor in lean-to extension. No basins etc upstairs.

So if treatment plant has a vent on it then just one AAV in the WC/shower room ground floor is all I need? No need for any "roof level..." or in-loft vent?

correct--just extend the pipe so its well above w/c pipe  connection  if you can 

[joe90]

On 04/01/2019 at 09:24, Ed Davies said:

so adding one would have created a big thermal bridge.

 

Not so, the stack could be joined into the underground pipe outside the thermal envelope then AAVs inside. This is what I did but our vent is on the detached garage.

[Ed Davies]

Actually, it was @JSHarris that said that; I just quoted him but I might have said something similar. In my case I want to avoid a vent stack by the house as I don't want one inside for thermal bridging reasons and to avoid roof penetrations and there's no vertical wall nearby to put an outside one on. Nearest vertical walls would nearly double the length underground pipework which seems silly.

[joe90]

2 hours ago, Ed Davies said:

Actually, it was @JSHarris that said that;

 

Oops, sorry. Yes an external stack connected through the wall underground can reduce the thermal bridge.