SBMS

Just watched it - absolutely crazy! Unfinished and on the market and the program is the biggest advert for it now as well. Hope they finish it and get to keep it.

We had a parapet wall so the cavity wall continued up past the edge of the roof.

Is 1800 include all fittings as well - flooring built in furniture etc as well? These things quickly add up

Have you any parapet walls? We went warm roof - was too difficult to detail ventilation.

I’m not doing it for the sake of it and I really don’t follow this logic - I don’t know where summers and temperatures will be in ten years - and I don’t know exactly how the house will respond to summer temperatures until I’ve actually built and lived in it. Why the aversion to a proposed system that can do exactly what you suggest (run at above dew point) but also have the capability to run lower for the sake of a mixer valve and temperature sensor? I can’t understand why future proofing in most contexts is seen as a good thing by self builders but I seem to be proposing heresy here in giving more flexibility 🤷‍♂️

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.

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??

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…

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?

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

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?

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.

Thanks Nick - is it the same for the wall mounted unit? I couldn’t find any information on that one..

Currently looking at the Panasonic aquarea heat pump and the wall mounted fan coil units upstairs. Has anyone any experience of piping these up and can advise on where/how the condensate outflow is connected? Can’t find any installation manuals online but have seen a drip tray for a parts list. Would rather it was plumbed in and hidden Than a drip tray. anyone installed these? Looking at the P-FMM15 for reference - https://www.aircon.panasonic.eu/GB_en/model/p-fmm15/

What have they calculated your design heat loss as? 7.5kW or 4.35?