@alec-morrow

Please explain an 'extension kit'.

Posted by: @alec-morrow

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Posted by: @hughf

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you wouldn’t need a weather compensated mixing valve in an ashp install as the ashp already has weather compensation

This is not correct.. the floor works on a different slope from radiators and needs its own mixer.

 

The good news is this is a standard design and the heat pump control is modular, so all you need is an extension kit from the heat pump manufacturers..

 

and of course a valve.. the esbe is fine -if  correctly specified 

I should have clarified, an ASHP install with a single emitter type (rads or ufh) would not require a separate weather comp’d mixer.

With different emitter types then yes, a separate mixer is required. I'm a fan of the Ivar Unimix3 mixing/pump stations.

Posted by: @alec-morrow

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the floor works on a different slope from radiators and needs its own mixer.

Unable to detect any slope for this floor, but we do have a separate mixer  😉 

Hi @heacol - I don't mean to hijack this excellent thread but I'm a bit of a newbie with my understanding of my ASHP and UFH/ radiators set up - this made me think about my own set up:

'If you control the boiler like this, on speed 1 or less, it will work like a Mix Energy tank and by using the stratification, will supply good high temperature hot water whilst keeping the solar thermal temperature as low as possible, which will enable it to harvest free energy.'

I was looking at my own pumps and piping - picture below of the pumps supplying the UFH (left) and radiators (right) and the types of pump (pump carton). As per the thread here, I didn't get much of a handover from our installers and have spent the past couple of years trying to understand my system and now I'm trying to optimise for the winter. For the purposes of the discussion, in this mixed set up with UFH and rads (which appears reasonably common), should I set the UFH pump to lowest speed (1 of 3)? And should the pump to the radiators also be set to 1 as well, given that I'm trying to have as low a flow temp as possible? Daikin also recommend a delta T between LWT and RWT of 5C for UFH and 10C for radiators (if using high temps) so I've gone with 5C, assuming that's correct, with weather compensation on. Our wet UFH is under a concrete screed with terracotta tiles over for info, and is in 4 bedrooms, 2 baths and a large hallway all with a single non-Daikin smart thermostat. Or have I totally misinterpreted this thread and I'm sending us off at a tangent? 🤔 

That question isn't going off at a tangent @marzipan71  It's exactly what we'd hope for as this discussion develops.

I'll leave others to comment on the pumps and temperatures. However I would like to make observations on the standard of your pipe insulation.

Whether the insulation is 'adequate' depends if the pump enclosures are situated in an area which you wanted heated anyway, thus heat-leakage isn't a problem for you.

But the silver 'Climaflex'-style wrap is pitifully thin, with gaps where it is being squeezed open, and bare angles/elbow-joints.

There's a well-illustrated feedback tutorial on pipe insulation for heat-pumps over on the OVO Forum. Those are mostly comments about deficiencies in materials/techniques employed by installation contractors appointed by BEIS for a government-funded trial. The largest contractor was so bad their contract was terminated.

That tutorial doesn't cover much on the subject of foil-insulation. This is also effective, but takes up less space. It can be used where pipes are quite close to each other. As it's a foil, you wrap it around the pipes; there's no tubular sections to purchase.

Superfoil is made by Boulder Developments in the UK and they can provide technical advice/support and samples if you want to explore that option.

Thanks @transparent - yes, happy to be insulation-shamed - guilty as charged 😀 The installers actually left us with no insulation on the heat pump piping at all, and in our first winter as a consequence the tech/ utility room got super hot of course. I hastily did the best I could both uninformed and with what was available from our local DIY store. I am not proud of the job, but it certainly was better than nothing. I've seen beautifully designed tech rooms in Austria with lovely piping arrangements and thick rubbery insulation and hoped that's what we would get from our installers but what we ended up with was uninsulated tangle of piping - and ours is better than a friend's place that looks like a map of the Underground hung on the wall in his tech room. I do intend to replace all the silver stuff and will definitely take a lead from the resources you've pointed me at and the foil sounds an easier install than tubes 😀 👍

If you're going to redo the pipe insulation anyway @marzipan71 then look at two other alternatives before you decide which strategies to use.

This video from Climaflex is excellent

and also consider the black elastometric pipe insulation marked Class-O and manufactured by Armaflex. They also do a UV-resistant variety, usually sold as 'solar pipe insulation'

You can get all these delivered from BES.

Secondly, your heat-pump installer not insulating the pipework is a breach of Building Regulations Part L (conservation of heat and power).

Please mention this as widely as you can (friends, family and work colleagues). It is quite understandable that customers won't know their way around these regulations. But we'd be quite happy to see photos posted here on the forum so that we can comment and advise before the final payment is made!

Thanks @transparent they are some very useful alternatives to consider. I will re-do the insulation this winter as its been bothering me that its not up to scratch (or regs). For background, we are expats living in Italy so the un-lagged pipework is possibly entirely normal here (I've seen things that make my non-professional hair curl so heaven knows what an expert would make of things...). Anyhow, trying to find out anything here about heat pumps is next to impossible and this forum is proving a lifeline for us 😀

For the benefit of the tape, the way your system is setup @marzipan71 is that you have a mixed (for ufh) and an unmixed pump group, connected to a horizontal low-loss header. The ASHP feeds into the header, under the power of it's own pump, then the two circuits draw from this, using their own pumps, the DAB branded ones you show in your photo.

Posted by: @marzipan71

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we are expats living in Italy

Ah... well that's very useful to know @marzipan71

Over the years I've sometimes needed to source variants of component parts when UK suppliers say they're "not sold in the UK". A couple of years ago I was after 30 sprung hinges for 'push to open' doors. There were two main manufacturers - both Italian!

A surprising quantity of plumbing parts sold in the UK under different brand names are actually sourced from Italy. Check out Tiemme as an example.

So you might more easily find plumbing/heating components where you are, than we can here in UK.

Hi @hughf - thanks for that explanation - yes we were told the left hand (B) system was for the UFH and the right hand system was for the radiators, as we have two 'zones' essentially with UFH in the bedrooms and radiators in the living areas (we are on one floor). Should the system be able to deliver water temps at two temps then at the same time? We've always had a feeling that it wasn't able to do that and when the UFH was running the rads would turn off - but that might just be due to our ignorance. As I mentioned on another thread, after installation I was trying to use our set up as if we still had a gas boiler and hence eye-watering consumption that first year. The advice on this thread seems to be to run the UFH pump here at 1 (our pumps are 1-3) - since I'm trying out weather compensation for the first time this winter with the smart thermostats set permanently higher than the desired room temps (per my reading of advice on the forum elsewhere) I'm thinking I should put the unmixed (radiator zone) pump on 1 also. Would it matter that the UFH is all brand new with new piping, but the radiators are using the original 12 or 15mm pipes?

Posted by: @marzipan71

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Hi @hughf - thanks for that explanation - yes we were told the left hand (B) system was for the UFH and the right hand system was for the radiators, as we have two 'zones' essentially with UFH in the bedrooms and radiators in the living areas (we are on one floor). Should the system be able to deliver water temps at two temps then at the same time? We've always had a feeling that it wasn't able to do that and when the UFH was running the rads would turn off - but that might just be due to our ignorance. As I mentioned on another thread, after installation I was trying to use our set up as if we still had a gas boiler and hence eye-watering consumption that first year. The advice on this thread seems to be to run the UFH pump here at 1 (our pumps are 1-3) - since I'm trying out weather compensation for the first time this winter with the smart thermostats set permanently higher than the desired room temps (per my reading of advice on the forum elsewhere) I'm thinking I should put the unmixed (radiator zone) pump on 1 also. Would it matter that the UFH is all brand new with new piping, but the radiators are using the original 12 or 15mm pipes?

Absolutely you can run the mixed UFH circuit at a different (albeit always lower) temp than the unmixed circuit. The blending valve that you can see in your photo has an adjustment knob on it, this sets the flow temp for the UFH to a fixed value, irrespective of what the weather compensation is doing to the flow temperature into the header and therefore into the radiator circuit.

It's perfectly possible that the system is wired so that when the UFH pump is running, the rad pump is not running - we don't know how this is wired.

You've got a daikin iirc? I don't know if their controller supports full control of both mixed and unmixed pump groups.

EDIT: From reading the schematic taken from the user manual of the 500ltr thermal store, it's clear to me now how this is plumbed and wired. It's complicated, but it's a neat setup.