Posted by: @lordstilton

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Mitsubishi Ecodan which have a 10kw unit and come with a preplumbed cylinder.

 

Avoid the pre-plumbed cylinder - it includes a low loss header which you dont want

Posted by: @lordstilton

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Is there anything I should be aware of that would favour one brand over the other? We are trying to be as cost effective as possible.

Installation/system design is more important than heat pump brand.

That said some have better (as in more flexible) controls.  Samsung is one of the least flexible, Vaillant one of the more flexible.  Dont know where Panasonic sits.  You should avoid using any external controls (not even a thermostat) with the exception of those that integrate with the heat pump bus (currently Adia, Homely and Havenwise only so far as I know) . 

If you are content to run on pure weather compensation, which is, for many, both the most efficient and the most comfortable, then any heat pump controler will do.  If you want to do eg a night time setback (or set forward to take advantage of a night time ToU tarrif) then only some will do this without invoking the room thermostat and effectively becoming on/off.  Vaillant is very good at this, again I dont know about Panasonic.  If you want a controller that integrates with Octopus Agile you need one of Adia, Homely and Havenwise, any of which render the capability of the native controller is largely irrelevant.

@aventus-eco is the Panasonic heat pump guru. Sean, can you please provide some insight here.

@editor I like Panasonic and Vaillant , Panasonic are fantastic heat pumps and so is the manufacturer support , what model of Panasonic are they proposing ? I’m assuming a J-series ? 

heartless is imperative to get correct and the amount of air changes per hour in each room can. Hugely affect the final results.

Panasonic you can run in full weather comp , you can also use the controller as a room thermostat , we don’t use that feature much. The Panasonic comfort cloud app you can set timers on the heating an the heat curve on different times and heat curve settings inline with the cosy tariff , it messes with efficiency but it takes advantages of cheap rates . You want to over heat the house on cheap slots. 

as for price his profit is in there with prices so what you can buy it for is irrelevant. No one is just charging labour as you can’t run a business and just covering wages alone.

My concern is you don’t feel comfortable with the installer or the umbrella scheme. I would take a breath and go and find a local installer you do like and can show you all their previous work. Not something to be rushed.

@jamespa Thanks James

The point on the low loss header was something I hadn't been aware of. 

I have looked at the 3rd party integrations and I can't see these are supported through Panasonic. A bit disappointing if this is the case. I appreciate I might not use it but I do enjoy the gadgets and ability to integrate with our batteries/solar. 

@aventus-eco Hi Sean. Thanks for your response and detailed breakdown on the Panasonic. It's the M series being recommended. I do like the model and from what I can tell most people seem very happy with it. 

I've maybe not described our situation accurately over text form but we are using the umbrella scheme as we are doing all the work ourselves including the install. The umbrella scheme is there to make sure it's installed in line with the MSC requirements and therefore grant eligible. There's not any labour for them as they are just supplying the kit and they have said if we can source the parts ourselves cheaper they are happy for us to do so. I appreciate they have their mark up on it though if we obtained all the parts from them. We pay a fee separately for the use of the umbrella scheme. 

I suppose my concern more centred on the drawbacks of Panasonic and whether alternatives in our heat loss range was something we should be considering more. As I say the umbrella scheme is very enthusiastic about Panasonic with ease of install, quality of the kits and remote support. 

Posted by: @lordstilton

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I have looked at the 3rd party integrations and I can't see these are supported through Panasonic. A bit disappointing if this is the case. I appreciate I might not use it but I do enjoy the gadgets and ability to integrate with our batteries/solar. 

Strange, perhaps it doesnt use modbus which the third parties tend to focus on initially and, unlike Vaillant (which also doesnt use modbus) is perhaps not a 'top seller' in the UK.

If you like tinkering you could of course, try to do something with Home Assistant or another framework, or even just python etc, assuming of course you can get access to the bus, which I imagine you can somehow.  Then you can play to your heart's content.  I use HA to monitor my Vaillant, but not to control, the inbuilt controller does all I need and more beside.

Tado claim to do a 'heat pump optimiser' which works with Panasonic, but when I spoke with their rep at installer show last June in order to try to establish whether it actually controlled flow temp or not (which is the key question), I got a load of BS.  So headed over to the Panasonic stand and the rep there, who was less full of BS, told that it didn't.  I was more inclined to believe them given the BS I got from Tado, but I could still be wrong on this.

@jamespa thanks James

From what i can see we should be able to do everything from the smart cloud, i liked the idea of some smart integration which could work with the solar aswell as using cozy/agile tarriff. In the grand scheme of things though i doubt we'd gain much.

Just coming back to the low loss header/buffer tank. The design had originally recommended a buffer tank which i rejected as i am aware they largely impact performance and are very rarely needed. However, on the scheme design this was a tank on the return flow so appears to be more of a volumiser than a hydraulich seperation. Again though i cant see why we would need it. Weve got 2 main runs splitting to seperate parts of the house in 28mm that then runs along each side of the house in 22mm with 15mm tails to the rads. Weve then got 5 1600 * 600 rads with the remainder in 1400 & 1200, all k2. I can't see we'd need any additional vooume for this.

Posted by: @lordstilton

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@jamespa thanks James

Just coming back to the low loss header/buffer tank. The design had originally recommended a buffer tank which i rejected as i am aware they largely impact performance and are very rarely needed. However, on the scheme design this was a tank on the return flow so appears to be more of a volumiser than a hydraulich seperation. Again though i cant see why we would need it. Weve got 2 main runs splitting to seperate parts of the house in 28mm that then runs along each side of the house in 22mm with 15mm tails to the rads. Weve then got 5 1600 * 600 rads with the remainder in 1400 & 1200, all k2. I can't see we'd need any additional vooume for this.

A tank solely in the return (upstream of where the return from the DHW joins so that it is not engaged during a DHW run) will do no harm but as you say may not be necessary.  What capacity is the heat pump, have you worked out the system volume/total # radiators, how large is the volumiser tank tank and whats your estimated heat loss?  Basically a volumiser does two things:

1. Ensures that there is sufficient heat in the system for defrost (typically about 50l)

2. Increases the run time during cycling - but the latter is material only if the volumiser tank volume is material in relation to the system volume

Im guessing you have at least 50l system volume in which case a volumiser tank is probably not necessary for (1).  However if you are likely to be oversized a good size volumiser will help with (2).  A tiny volumiser would be pointless however provided you have sufficient system volume for (1)