Condensation Drains - Connecting to waste

[Barney12]

Hi All

 

Quick question:

 

I've got two condensation drains to connect up from my heat battery and MHRV.

Whats the best way to connect to the soil stack?

Annoyingly the heat battery is a 15mm pipe outlet (from a 1/2" BSP connection) and the MVHR is 21.5mm overflow type plastic pipe.

Even more annoyingly the heat battery has no form of trap.

 

I think I'm going to have to create some form of homebrew connection. Perhaps using one of these to create the sealed outlet?

https://www.monsterplumb.co.uk/hotun-hiflo-shield-white-black-RATech-HW100C-dry-trap-tundish?language=en&currency=GBP&gclid=EAIaIQobChMI49O69a7F1QIViIePCh0cRwYhEAQYBCABEgIN3fD_BwE

[Jeremy Harris]

Is the heat battery a Sunamp PV?  If so, then it's not a condensate drain, but a pressure relief valve overflow, and needs to connect to a visible outlet.  I connected ours to a tundish, then fed the outlet of the tundish down to a waste pipe, that runs across and connects to the MVHR condensate drains (there are two on ours).  The drain from the water softener also connects to this.  This waste then runs vertically down inside the ground floor airing cupboard in the utility room below, where there is a standard U bend trap on the near horizontal section that runs across behind the units to the soil stack.  The trap is kept topped up by the regular drain from the water softener, which stops it drying out in spring and autumn, when there may well be no condensate from the MVHR to keep the trap topped up.

 

You may need to fit a dry trap, like this HEPvO: http://hepvo.com/ 

[Barney12]

50 minutes ago, JSHarris said:

Is the heat battery a Sunamp PV?  If so, then it's not a condensate drain, but a pressure relief valve overflow, and needs to connect to a visible outlet.  I connected ours to a tundish, then fed the outlet of the tundish down to a waste pipe, that runs across and connects to the MVHR condensate drains (there are two on ours).  The drain from the water softener also connects to this.  This waste then runs vertically down inside the ground floor airing cupboard in the utility room below, where there is a standard U bend trap on the near horizontal section that runs across behind the units to the soil stack.  The trap is kept topped up by the regular drain from the water softener, which stops it drying out in spring and autumn, when there may well be no condensate from the MVHR to keep the trap topped up.

 

You may need to fit a dry trap, like this HEPvO: http://hepvo.com/ 

 

No, it's the GSHP water to air exchanger for the MHRV. Airflow call it a 'heat battery'.

I agree either a HEPvO or the dry tundish I linked to (it's a tundish combined with a dry trap).

But whatever I chose I'm going to have to terminate 15mm  copper or HEP2O and 21.5mm plastic overflow into something not designed for either  

Ive done some googling and there are a few forum posts that suggest you can connect 21.5mm plastic waste into a 22mm compression fitting if you use a 3/4" olive. Perhaps our expert @Nickfromwales knows. So I could get everything terminating in 15mm to that 1/2" inlet on the dry tundish with a bit of buggering around with reducers. 

Im guessing that the 'heat battery' and MHRV will rarely keep a trap filled before it dries out? 

 

Alternativelt then hen it wouldn't be hard to make the required connections with something like CT1 as I doubt the water flow is ever going to be more than a trickle or drip.

 

[Jeremy Harris]

I can confirm that a 15mm inlet, 22mm outlet, plastic tundish will fit 21.5mm plastic overflow pipe OK, as it's what I've done.