Panasonic aquarea - dual zone cooling @ diff temps possible?

[SBMS]

We are in the process of installing all the pipework for a Panasonic M series ASHP - 7x fancoils upstairs and UFH downstairs.  

 

My goal - and reason for picking the Panasonic - was the ability to run dual cooling zones via the ASHP.  My plan if it gets hot was to run the fancoils at 10 degrees and the UFH at 15-16 degrees.  The installer - who has been great - has had some conflicting information from Panasonic.  Initially we were told that this was fine, and the Panasonic supports dual cooling zones, but we've been waiting for a hydraulic schematic from Panasonic.  Today we had a technical engineer from Panasonic tell us that he's not sure this is possible natively with the system, and its back to us.  We are seeking advice further from Panasonic tech installation.

 

In the meantime - has anyone managed to design and install this system to produce an FCU cooling loop at 10 degrees and UFH at a higher temp and if so how? Our installer is looking into it as well and may come back with a design, but are rightly nervous of designing their 'own' and not following a Panasonic approved schematic..

 

I know that many will say that its not necessary, run it at one temp etc. I get that, and if thats the fallback so be it.  But we've lagged all the pipework for the FCUs, installed condensates throughout and basically prepped it for low temp cooling to maximise the cooling output of the FCUs.  I really want to make that work, without having to push 16 degree water around both circuits and would be grateful if anyone has got this to work, or knows of a way.

Edited Tuesday at 19:20 by SBMS

[-rick-]

No specific knowledge here but I am curious:

1. What is your current plan?

2. They claim to support dual zone heating with different temps? I'd assume so. How are they doing that?

3. Are you referring to purely simultaneous cooling? Can it do one zone at a time at different temps?

 

I have a couple of ideas for things you could do but depends on the proposed setup.

[Nick Laslett]

Not sure how the ‘M’ is different to the ‘J’?

 

Here are the pages from the installation set-up for the ‘J’ ashp about 2 zones, different temps. 
 

https://www.panasonicproclub.com/uploads/GB/catalogues/2023/UK_INSTALLATION_MANUAL_H 2023v3.pdf

Edited Tuesday at 20:36 by Nick Laslett

[SBMS]

I wasn’t sure if the Panasonic dual zone control is built for heating - not for cooling but that seems To indicate it might. Alternatively I wondered if I had to provide dual zone cooling by hydraulic means. 
 

i am not an engineer but was thinking…

 

Heat pump produces 10deg water into buffer 

FCU takes 10 deg water direct from buffer and returns back to buffer. 
UFH branch comes off buffer with a 3 way thermostatic mixing valve with a hard min of say 16 degrees. Valve blends the 10deg water from buffer with the return from UFH circuit with output to the UFH.

UFH circuit would be separately pumped and return to buffer. 
 

i could also go for a more advanced controller at the mixing valve that could read the UFH temp and mix accordingly based on the temp -

or even integrate with a dewpoint sensor. 
 

Would something like the above work?

Edited Tuesday at 20:51 by SBMS

[-rick-]

Definitely sounds like it should be possible. They are relying on mixing valves and running the heatpump at the highest (heating) or lowest (cooling) temperature so it's not necessarily the most efficient but I wouldn't expect you to need the very low cooling temps outside of heatwaves.

 

 

[SBMS]

2 minutes ago, -rick- said:

Definitely sounds like it should be possible. They are relying on mixing valves and running the heatpump at the highest (heating) or lowest (cooling) temperature so it's not necessarily the most efficient but I wouldn't expect you to need the very low cooling temps outside of heatwaves.

 

 

This looks almost exactly like what I designed but it’s built into the heat pump!! Is that a fair summary??

[JohnMo]

Read a lot of ASHP manuals (yes sad), they all seem to work in a similar fashion. The ASHP receives a zero volt signal to run the second operating temperature, otherwise it runs at normal temperature So if your UFH is only calling for heat only it runs at one temperature, if your upstairs also calling for heat the second set point comes in, a mixer valve then mixes up/down in cooling/heating

 

Work equally well for heat and cooling.

 

You need (generally) an electronic mixer valve,  volt free thermostat in addition to what in your fan coils, maybe a buffer or ideally a volumiser to cover just the fan coils calling for heat.

 

Adds loads of additional complexity.

[-rick-]

3 minutes ago, SBMS said:

Heat pump produces 10deg water into buffer 

FCU takes 10 deg water direct from buffer and returns back to buffer. 
UFH branch comes off buffer with a 3 way thermostatic mixing valve with a hard min of say 16 degrees. Valve blends the 10deg water from buffer with the return from UFH circuit with output to the UFH.

UFH circuit would be separately pumped and return to buffer. 

 

I think the issue is with the mixing valve. A normal analog thermostatic valve can't have different set points for hot and cold. I'd guess that many digital ones also require more setup work/software support to do this. Maybe their inbuilt control of digital valves is the problem? If so, wouldn't seem hard to make sure you bought valves that could handle two set points and wire them seperately from the rest of the system. Not sure off hand why they would need to be wired into the heatpump except for monitoring reasons, they should be set and forget.

[SBMS]

5 minutes ago, -rick- said:

 

I think the issue is with the mixing valve. A normal analog thermostatic valve can't have different set points for hot and cold. I'd guess that many digital ones also require more setup work/software support to do this. Maybe their inbuilt control of digital valves is the problem? If so, wouldn't seem hard to make sure you bought valves that could handle two set points and wire them seperately from the rest of the system. Not sure off hand why they would need to be wired into the heatpump except for monitoring reasons, they should be set and forget.

Is the same issue present in the Panasonic ‘2 zone layout both mixed’ schematic? Or does it control The mixing valve using the zone water sensor? 

Edited Tuesday at 21:01 by SBMS

[Nick Laslett]

I don’t believe you need the dual temperatures. Supply water just above the dew point and I expect you will get the house cool enough with UFH and Fancoils running at those temps. 
 

Plenty of anecdotal comments here about Fancoils delivering at temps above dew point.

 

The trick is to never let the house overheat in the first place. The ASHP weather compensation will supply the cooling before the house ever gets really hot. 
 

You can use Home Assistant connected to a dew point sensor to control the Panasonic ASHP flow temp. @Dave Jones
 

Quote

As its actually nice today, tried out running the heatpump in reverse to cool the house.  To keep above dewpoint (home assistant takes care of this) set at 16C, had the slab down to 16 within 4 hours and the house is noticeably cooler when walking inside. Have 5 panasonic fancoil units in the bedrooms which will test once the painters are done.

 

[SBMS]

13 minutes ago, Nick Laslett said:

I don’t believe you need the dual temperatures. Supply water just above the dew point and I expect you will get the house cool enough with UFH and Fancoils running at those temps. 
 

Plenty of anecdotal comments here about Fancoils delivering at temps above dew point.

 

The trick is to never let the house overheat in the first place. The ASHP weather compensation will supply the cooling before the house ever gets really hot. 
 

You can use Home Assistant connected to a dew point sensor to control the Panasonic ASHP flow temp. @Dave Jones
 

 

Thanks for this but seeing as I have already installed and lagged pipes and CAN run at 10 degrees (which also dehumidifies) I’d like the option of it. Would also like FCUs sized appropriately and not oversized to cope with a reduction in output when running at 16deg. If it turns out I don’t need to I can simply set both zones to 16 degrees,

enjoy a better COP and achieve the same. Im just keen to understand if the heat pump natively supports this…

Edited Tuesday at 21:22 by SBMS

[JohnMo]

6 minutes ago, Nick Laslett said:

Fancoils delivering at temps above dew point

But they have to be sized correctly to do that.

 

7 minutes ago, Nick Laslett said:

trick is to never let the house overheat in the first place

True

7 minutes ago, Nick Laslett said:

You can use Home Assistant connected to a dew point sensor to control the Panasonic ASHP flow temp

You can, but after loosing internet (signal from source - not house internet issue) for quite a few hours the other day, I wouldn't let anything internet based anywhere near the heating system.

 

In most of the UK if you never allow house to overheat, you run at about 13 degs without any condensation issues.

[SBMS]

1 minute ago, JohnMo said:

But they have to be sized correctly to do that.

 

True

You can, but after loosing internet (signal from source - not house internet issue) for quite a few hours the other day, I wouldn't let anything internet based anywhere near the heating system.

 

In most of the UK if you never allow house to overheat, you run at about 13 degs without any condensation issues.

Thanks and understand everyone’s points. Let’s just assume I understand everyone’s points that I may not need to run it that cold and could run above dewpoint temp. Id still like to size my FCUs appropriately and can see no downside to have a system that can do 10

deg supply - even if its only on a couple days a year. 
 

From the literature it looks like the heat pump does provide this and it’s design is quite similar to my niaive design that didn’t rely on the Panasonic controller??

[Gus Potter]

4 hours ago, SBMS said:

We are in the process of installing all the pipework for a Panasonic M series ASHP - 7x fancoils upstairs and UFH downstairs.  

 

My goal - and reason for picking the Panasonic - was the ability to run dual cooling zones via the ASHP.  My plan if it gets hot was to run the fancoils at 10 degrees and the UFH at 15-16 degrees.  The installer - who has been great - has had some conflicting information from Panasonic.  Initially we were told that this was fine, and the Panasonic supports dual cooling zones, but we've been waiting for a hydraulic schematic from Panasonic.  Today we had a technical engineer from Panasonic tell us that he's not sure this is possible natively with the system, and its back to us.  We are seeking advice further from Panasonic tech installation.

 

In the meantime - has anyone managed to design and install this system to produce an FCU cooling loop at 10 degrees and UFH at a higher temp and if so how? Our installer is looking into it as well and may come back with a design, but are rightly nervous of designing their 'own' and not following a Panasonic approved schematic..

 

I know that many will say that its not necessary, run it at one temp etc. I get that, and if thats the fallback so be it.  But we've lagged all the pipework for the FCUs, installed condensates throughout and basically prepped it for low temp cooling to maximise the cooling output of the FCUs.  I really want to make that work, without having to push 16 degree water around both circuits and would be grateful if anyone has got this to work, or knows of a way.

So you posted this 3 hours ago, hopefully I caught you in time. I might not have. but hey ho.

 

Points: 

 

1/ If you are designing your heating cooling system based on what is available above the floor, ASHP then I think you are making a big mistake. STOP NOW and make sure you build in redundancy into your fixed UFH pipes that are not maintainable.

 

If you dought me go back and ask you designer if they will warranty what is going on under the floor and for how long. Ask, what if I come to sell the house, is that going to impact on the asset value. 

 

2/ If your UFH pipes don't have the flexibilty to accomodate in the future a different ASHP then you are totally locked in. You will regret it. 

 

@SBMS

In the meantime - has anyone managed to design and install this system to produce an FCU cooling loop at 10 degrees.

 

To do this you need more loops. This also does my head in. You have a sofa, say big patio doors, the sofa insulates the floor but just inside the glass doors the floor gets hot! UFH design is a craft, but most is commonscence. What is not good sense is to take software output and think the computer knows best which far too many on BH are doing ! The software is a guide and that is it!

 

Let common sense prevail. 

 

But at the big glass doors in the winter you have a thermal bridge so the floor gets cold here, drafts come down off the glass, I close up the loops here! Loop cad does not pick this up for example and many designers just bury their heads in the sand. 

 

In the summer the floor next to the glazing gets hot, so here you need to cool it most so the closer centres helps.

 

What I'm trying to say is that you do your pipes under the floor with pragmatism and benefiting from the "no shite" advice I give you. That then opens up what is going on above the floor and gives you options for a system that will work for 50 years and not pelt the asset value of your house. 

Edited Tuesday at 23:48 by Gus Potter

[SBMS]

9 hours ago, Gus Potter said:

So you posted this 3 hours ago, hopefully I caught you in time. I might not have. but hey ho.

 

Points: 

 

1/ If you are designing your heating cooling system based on what is available above the floor, ASHP then I think you are making a big mistake. STOP NOW and make sure you build in redundancy into your fixed UFH pipes that are not maintainable.

 

If you dought me go back and ask you designer if they will warranty what is going on under the floor and for how long. Ask, what if I come to sell the house, is that going to impact on the asset value. 

 

2/ If your UFH pipes don't have the flexibilty to accomodate in the future a different ASHP then you are totally locked in. You will regret it. 

 

@SBMS

In the meantime - has anyone managed to design and install this system to produce an FCU cooling loop at 10 degrees.

 

To do this you need more loops. This also does my head in. You have a sofa, say big patio doors, the sofa insulates the floor but just inside the glass doors the floor gets hot! UFH design is a craft, but most is commonscence. What is not good sense is to take software output and think the computer knows best which far too many on BH are doing ! The software is a guide and that is it!

 

Let common sense prevail. 

 

But at the big glass doors in the winter you have a thermal bridge so the floor gets cold here, drafts come down off the glass, I close up the loops here! Loop cad does not pick this up for example and many designers just bury their heads in the sand. 

 

In the summer the floor next to the glazing gets hot, so here you need to cool it most so the closer centres helps.

 

What I'm trying to say is that you do your pipes under the floor with pragmatism and benefiting from the "no shite" advice I give you. That then opens up what is going on above the floor and gives you options for a system that will work for 50 years and not pelt the asset value of your house. 

Sorry Gus I'll be honest I'm not sure what you mean about designing a system based on what is available above the floor??

 

For clarity: am doing UFH downstairs, and wall mounted fan coils in bedrooms upstairs? Not sure why I would need 'more loops' for FCU cooling? They are on one circuit, drawing water from the buffer?

 

Might have misunderstood though.