Condensate issues

[Redoctober]

Here goes - It seems I under estimated the area needed for my ASHP condensate pipe to drain away into, as the condensate has been backing up recently. [Not draining away via the soakaway created as expected.]

 

Upon inspection, I thought I could just dig a larger area but unfortunately, the area I am working with is clay based. In fact I managed to dig down a good 900mm but all I have done, is to create a clay walled well! Yes, it will no doubt take time to fill up but it is not a "long term" solution.

 

So, one possible solution is to connect the ASHP condensate pipe to a pipe which in turn will "tap" into a nearby down-pipe / gutter system - see image.

 

My question is this - How best to drill / create a hole in the "gutter" / "drain" to accommodate the new drainage pipe without breaking it and causing me all sorts of additional problems'

 

As ever, your thoughts are welcome.

[joe90]

I thought I was going mad, I don’t recall having a condensate drain on my ASHP. Just looked again at my instructions and no mention!! Any condensation from the “radiator” just runs down the back into the soil and is very little. I only thought condensate drains were on gas boilers  and MVHR units???. Frankly any drill will be ok with underground drainage pipe, perhaps a hole cutter the least risk of shattering it (very unlikely).

Edited April 25, 2021 by joe90

[Redoctober]

@joe90 - Interesting. Our Mitsubishi Ecodan 5kw has a pipe coming form the base of the unit and we were instructed to create a soakaway for the pipe to drain into, as the unit will produce  a good few litres of condensate. I did that but unfortunately the soakaway I created is surrounded by clay. Hence the issue. 

Thanks for the advice re hole cutter etc.

 

[ProDave]

42 minutes ago, joe90 said:

I thought I was going mad, I don’t recall having a condensate drain on my ASHP. Just looked again at my instructions and no mention!! Any condensation from the “radiator” just runs down the back into the soil and is very little. I only thought condensate drains were on gas boilers  and MVHR units???. Frankly any drill will be ok with underground drainage pipe, perhaps a hole cutter the least risk of shattering it (very unlikely).

My LG ASHP does not have a condensate drain either.  Any condensate just drips out of the bottom onto the paving slabs and runs off into the surrounding ground.  This usually only happens when it defrosts.

[Bruno]

My Vaillant aroTHERM Plus also produces a lot of condensation. Mine is hanged on the wall and for now it's just dripping to the floor. But I also have to find a better way for that. 

[joe90]

1 hour ago, Redoctober said:

as the unit will produce  a good few litres of condensate.

I understand as we are on solid yellow clay, yes run it into the drain, no probs.

[wozza]

Is there not a chance that such a small pipe so close to the surface will freeze in the colder months?

[Redoctober]

3 hours ago, wozza said:

Is there not a chance that such a small pipe so close to the surface will freeze in the colder months?

 

 Yes, absolutely and I will take that into consideration when fitting a pipe etc. The thin pipe shown is actually a drainage rod used for demonstration purposes, but thanks anyway.?

[markharro]

We are having an 5kw ASHP installed in a couple of months so my question is what thickness of concrete pad to pour for it and how to deal with the drainage ie will putting the pad over Xmm of hardcore do?

[Dave Jones]

19 minutes ago, markharro said:

We are having an 5kw ASHP installed in a couple of months so my question is what thickness of concrete pad to pour for it and how to deal with the drainage ie will putting the pad over Xmm of hardcore do?

 

no, id drain it to nearest run. you will have a sheet of ice come the winter.

[Nickfromwales]

14 minutes ago, Dave Jones said:

 

no, id drain it to nearest run. you will have a sheet of ice come the winter.

Not if the ground is permeable. Waste of time/ money.

The Stiebel Eltron unit we've just installed has a condensate outlet underneath which is simply dripping down in a 150x150mm cut-out in the concrete plinth to ground. I've dug down about 700mm and back-filled with 10mm gravel as a soakaway. Works perfectly well.

@markharro, dig a hole where the condensate will fall, fill it with a hosepipe flowing at 0.2 l/p/m and if it doesn't back up, end of. 

 

If it's a few £ more to extend a local rainwater pipe and add a gulley, then of course do so. But it's massive overkill unless you're in solid, impermeable clay.

[markharro]

Thanks @Nickfromwales this is exactly what I was looking for. Is your 700mm of gravel under the 150x150mm cut out or under the whole pad?

 

I was a little thrown by this issue when the plumber who came last week to pressure test our UFH manifold told me that the ASHP unit could discharge up to 100 litres of water a day. Even to a layman like me this seemed improbable.

[Nickfromwales]

1 minute ago, markharro said:

Thanks @Nickfromwales this is exactly what I was looking for. Is your 700mm of gravel under the 150x150mm cut out or under the whole pad?

 

I was a little thrown by this issue when the plumber who came last week to pressure test our UFH manifold told me that the ASHP unit could discharge up to 100 litres of water a day. Even to a layman like me this seemed improbable.

Nope, just drilled the slab when cured, made an oversized hole so we could get hands in and dig down. Your plumber could be right if an ASHP is installed in very adverse conditions, which most, sadly, are.

[markharro]

What do you mean "adverse conditions" - I assume you mean poorly installed? What should I look out for to quality check the install?

[Nickfromwales]

24 minutes ago, markharro said:

What do you mean "adverse conditions" - I assume you mean poorly installed? What should I look out for to quality check the install?

Not necessarily, just where they're running flat out etc / defrosting like crazy etc. Poorly implemented / poorly selected etc vs just crap workmanship  

 

FYI, workmanship is less likely to cause issues vs poor design / incorrect specification. ASHP's are 1 pipe in and 1 pipe out. Not exactly rocket science, but the design does need someone with a few extra braincells.

Most plumbers come ASHP fitters just refer to predefined standards, particularly when advising folk about ow-energy > PH builds, and hey're j( mostly ) just covering their arses at that point and over-specifying AFAIC.