SBMS

Panasonic will also do a heat loss calculation as part of their design so they can size the correct unit

Hi lizzie ive just gone through this process with Panasonic and our installer. I wanted the setup you are aiming for - UFH as zone 1 and fancoils upstairs on zone two. Everything I have read on the system points me to it being well designed and totally capable for what I want. The weak link was indeed Panasonic uk design. Eventually I got the contact details of the design team themselves and liaised directly with them. I don’t think many people in the uk use the two zone setup so it took a while to get the design so we all understood it. The benefit is that they produce the full hydraulic and electrical design (not that straightforward) AND then warranty it. So if anything is incorrect Panasonic pick up the tab. Your installer just follows it. the rep was useless and just tried to sell me aircon. The best thing to do is strongly suggest that the design team follow Panasonics own reference diagram which you can find in their main manual. Can forward if you need. The Panasonic control unit is fairly smart and supports multi zone by way of controlling a mechanical blending valve and water temperature sensor. In cooling mode this is what protects your UFH from running too cold. Return water is blended to mix up to a limiting temperature (say 16 degrees). Fancoils can run at 7 or 8 degrees which is what the buffer will be chilled to. You can even do the reverse in winter and have your zones on different temps if you want the fancoils running a bit hotter ( probably not necessary). All my pipework was lagged. In theory it should be as good as aircon. PM me if you want the email For the guy I spoke to at Panasonic. It’s a very capable well designed system though and only one I came across that natively controlled multiple zones, had the fcus from same manufacturer etc. and the tcap range is very impressive in the way it can maintain a constant output irrespective of environment temperature.

This was my reasoning. And I have loxoned everything to death so can automate the immersion (a timer would probably have sufficed like JohnMo said - but does mean I can integrate PV production to top up when it’s generating most). To respond re eco credentials - it’s a balancing act right? Building a house isn’t an eco statement for me. But where I can I have tried to minimise heat loss with good quality triple glazing, 200mm cavity, airtightness (meaning I need MVHr) etc. Then the home automation and using ASHP for cooling is for comfort and because I like the hobby of tinkering with software and programming. I guess it’s more eco friendly to only have one unit to save resources on building, shipping etc, but wasn’t primary motivator. the ultimate eco statement is not to build a new house at all probably and buy existing stock - but then most of us wouldn’t be here would we?

True but that’s a fraction of runtime really - and can be scheduled in the early hours (when it’s cheap). Personally I think simplicity is having one system doing both, but maybe it’s my OCD not wanting a unit sitting there unused half the year.

I considered whether to install AC or not but have decided to fit fancoils to the first floor bedrooms and landing areas and have a two zone ASHP system. So can cool to proper AC levels in summer if needed. Wasn’t hugely more than a standard ASHP and was roughly the same as not doing UFH upstairs. And installed MVHR as well.

I looked at these but they were quite a bit more money than GSE I think

Yes although going to be tough to do this with only 250mm or so to the verge..

I think it’s a 500x250

I could do a smaller panel but try 5 in landscape… my roof is 9300mm wide and panels would be 8810 (5x1762). How much clearance is needed each side (slate roof)?

Thanks John I get that. I was wondering if anyone has sourced a tray that fits this panel size. From GSE website I think they do a 1990x1090 tray but cannot source it anywhere so wondered if anyone else had found it. As you say alternative is to step down and use a smaller tray just don’t get as much PV then…

I have a 9300mm x 3500mm garage roof (slate) and I’m wanting to install in roof system. The roofers are happy to install whatever I supply and I’m just trying to find out the best system to install. I’ve pretty much settled on GSE as this seems most popular. I’ll be putting panels on both sides of the roof. I want max kw for the roof And am looking at JA Solar panels either 500w panel (1134x1953) or 450w panel (1134x1762). Im on 3 phase. I think the most panels I can fit is the 500w panel in 2 rows of 4 on each elevation (4kW per side). In portrait most I can get on with 500w panel is 7. I’m struggling to understand how the landscape system works for GSE And what trays I would need for a 2 row landscape layout (and where to find these from as sourcing is quite tricky. I don’t know if GSE actually supports this panel size?

Asking because I’ve closed our 200mm cavities with 100mm PIR (will have eps beads blown behind) fully foamed and taped all gaps with illbruck fm330 and airtight taped across the window to cavity joint and done soudatight on cavity to inner block joint. Wasn’t sure if I also needed to insulate reveals as I don’t have much left on the aluminium frames.

@Nickfromwales does this negate the need for insulated PB?

Yeah, you’d still be subject to article 4 conditions. I don’t think there’s a specific part of statute relating to ‘when’ PD rights kick in. As it was explained to me PD rights apply to a ‘dwelling house’. I don’t believe there’s any single definition of a dwelling house but the planning consultant explained there’s a common law test that refers ‘To capability of occupation’. This is a ‘matter of fact based on the probabilities’. In actual fact this is what councils use to pre-assign valuation bandings to prevent delays in council tax registration, where builders defer completion certificates to prevent council tax. It works both ways in this sense. Fundamentally my take away is that there is no single point in time or concrete certified point at which a building acquires PD rights except for the above definitions of dwelling house.. If anyone can cite planning law that states a ‘completion certificate’ must be present for PD rights to come into effect I’d be interested…

It’s the definition of ‘complete’ - As my planning consultant explained In law permitted development rights are granted when the building is ‘Completed and capable of occupation as a dwelling house’ meaning that the building has reached a stage of physical construction where, as a matter of fact and degree, it is ready and capable of being beneficially used as a home for its intended purpose. Relevant case law here is well trodden and is actually the reason why councils often rate a building for council tax as capable of habitation prior to a completion certificate being issued. The single line my consultant explained was whether it was ‘capable of occupation’. Building regs or completion certificate is irrelevant, it’s the state of the building on the ground that matters.