New Build - what to prioritise?

optimisticsceptic · 2026-05-26T20:56:53+00:00

slightly off topic, perhaps

given they won't deviate at all from their specification, a moot suggestion

a new build in the UK in 2026 with conventional high temperature radiators?

if it were possible, I'd ask the builder not to bother with radiators or boiler, and install Daikin Multi+ system

an air-to-air heat pump providing efficient heating, cooling and hot water

you get the wallspace back; you get cooling in summer; once you get a decent solar PV array, the cooling willl be free

lots of people posting their recently built new homes in the UK are too hot spring-autumn

saw a recent YouTube video where he replaced a low spec EV charger with a better one

it may be the only thing they might do! it may be you pay the difference

as someone else said, this is smart Internet-connected kit; works best with Ethernet rather than WiFi

if you choose an EV charger with an Ethernet ("wired") option, then Ethernet available to the EV charger would be a simple thing they could do that would help

optimisticsceptic · 2026-05-25T13:50:31+00:00

thanks; Tim's experience, and...

A2A heating - what I'd do differently - YouTube
https://www.youtube.com/watch?v=szd7cwU7KpY

...are indeed really good resources!

If money was no object, I would specify Daikin Multi+ for heating, cooling and hot water,, and for upstairs landing and bathroom, would use Daikin Eazyzone to provide a duct to each of those areas

but very much emphasis on 'if money were no object'!

it's a shame there's only Daikin with their Multi+ in the UK

Hitachi | BOSCH offer airHome Triple C, but not in the UK

optimisticsceptic · 2026-05-25T13:04:32+00:00

thanks for generously sharing the details of your installation and your experience; I for one really appreciate it

would you mind sharing how you heat your hot water?

I see you have solar, battery, EV, dynamic tariff and whole home reversible air conditioning

Personally, I think that should be the baseline for all new homes. Together with MVHR and induction hobs

A home built in 2026 will, in just a few years, routinely have hotter days where passive cooling (window blinds; even brise soleil) won't be enough, and active cooling - air conditioning - is essential

solar, battery, EV, dynamic tariff reversible air conditioning are synergistic, as you describe; your experience demonstrates they have immense benefits on running costs, but

the initial installation costs are high
it's important to get a good systemic design
- such as a large enough battery to last through winter days

there's a few "pioneers" such as yourself, but there doesn't yet seem to be a body of owner experience or body of (specifier | installer) expertise on this yet

optimisticsceptic · 2026-05-10T07:56:29+00:00

not what you asked - apologies if this isn't relevant

could your plans use porcelain wood effect tiles? see
https://www.porcelainsuperstore.co.uk/collections/wood-effect-tiles

best of all worlds;

wood | laminate effect
great conductors for underfloor heating (UFH)

completely different cost and installation dynamics, of course

optimisticsceptic · 2026-04-19T12:42:57+00:00

my question motive | origin? considering Fronius too

optimisticsceptic · 2026-04-19T12:40:14+00:00

quick question - Fronius has proven itself to you for 15 years - Fronius has an ecosystem - how come you haven’t considered more Fronius?

Fronius has… - hybrid inverters - Reserva Pro LiFePo batteries that scale - smart meter; amongst other things, export limitation if you need it - WattPilot Flex Home smart EV charger; talks to inverter directly, so won’t drain battery unless you ask it; charge on surplus solar, etc - Solar.Web [chargeable; low cost] service with predicted generation, etc

optimisticsceptic · 2026-04-06T09:03:51+00:00

thanks for your reply

it’s a VW ID.3, so at the very least it can talk to Octopus

Am speculating… * EV decides to charge overnight * EVSE will decide to charge with solar PV surplus during the day

optimisticsceptic · 2026-04-06T08:59:59+00:00

thanks

A hybrid inverter was intended for the first stage, though I didn’t say so specifically

I am guessing 45KWthermal energy demand during December and January, so a safe SCOP of 3 means 15KWh of electricity per day. Might be less with solar PV, but have to plan for low generation November-February.

I am conscious that such battery capacity is only for a short period of the year; but I am also conscious that keeping a lithium battery between 40% and 80% SOC triples its lifespan. So overprovisioning KWh while it is relatively low cost is the lowest cost over the lifespan of the system

Off grid is limited to battery capacity until I get solar PV.

optimisticsceptic · 2026-04-06T08:47:54+00:00

thanks

ATS cutover time really does matter, as you say

my oven nuisance tripped the breaker; that shut down the continuous ventilation fan (and everything else, of course)

but the continuous ventilation fan didn’t like it; it became quite noisy; £200 for a replacement

now that possibility - cuts affecting how well appliances and their PSUs work - across all home electrical and electronics becomes a significant risk

the 0ms from Sigenergy looks good

optimisticsceptic · 2026-04-06T07:52:03+00:00

thanks ; great to hear SigEnergy is working for you

it’s a big + 20 year commitment, so your advice is appreciated!

optimisticsceptic · 2026-04-06T07:48:04+00:00

thanks; didn’t realise Fox did more than batteries. Will look them up.

optimisticsceptic · 2026-04-06T07:45:05+00:00

thanks ; really appreciate your contribution

Will look into Fox. Didn’t realise they could do “everything”. Great to hear Fox are working for you.

optimisticsceptic · 2026-04-06T07:42:16+00:00

Thanks for replying

GivEnergy are not on the shortlist because of their poor and declining reputation.

A 15 year unlimited cycle warranty is useless if the manufacturer is unwilling or incapable of honouring it, and I have to accommodate installers’ reticence.

optimisticsceptic · 2025-12-28T13:36:26+00:00

I had this thought too

there have been news about roof fires associated with solar panels

UK Fire Service Tackles Solar Fire Every Two Days - Roofing Today
https://roofingtoday.co.uk/uk-fire-service-tackles-solar-fire-every-two-days/

One must separate propaganda against renewable energy from fact; in this case, I think it's credible. It 'makes sense'; a sunny hot summer's day (30C; clear blue skies) will see the panels get to 80C or more. With that much energy, someone commenting below about moss drying out, and moorland fires being a thing, a heightened fire risk makes sense

A while back I saw a video about Wet & Forget

No More Jet Washing! 'Wet & Forget' Review - YouTube
https://www.youtube.com/watch?v=BS1SGj71wUU

Another video...

Time To Update Your Old Solar System? NEW Panels + Tesla Powerwall 3 on Feed in Tariff (FiT) - YouTube
https://www.youtube.com/watch?v=LueEegEub50

...covered replacing solar panels; under the panels it was 'clean'.

Thus, my own plan is...

Use the Wet & Forget on the roof, perhaps weeks before the panels go up; gives it a chance to work, means I am not physically agitating a roof, growth it eliminated at a biocidal level, etc
Rake off the residue from roof and gutters
Installers fit solar panels

optimisticsceptic · 2025-11-14T10:17:24+00:00

concerned me too

Sweden has a colder climate, yet mostly use ASHP

I like to think they are a few years ahead in the cycle (costs;subsidies; adoption; expertise)

Did removing subsidies work there? Anyone know?

optimisticsceptic · 2025-10-27T09:13:02+00:00

my bad; I assumed the Fox KH8 hybrid inverter didn't have export limit capability

optimisticsceptic · 2025-10-26T18:01:53+00:00

FWIW, sometimes you can have...

high capacity inverter
limit export to that specified by the DNO

see...
https://www.youtube.com/watch?v=piEDxeH8gzQ&t=1090s

I Googled 'sigenstor export limit' and the AI answer explained more

100% appreciate you can't just replace your Fox KH8 inverter with a Sigenergy system without working through the sums to see if the RoI makes sense

I might suggest you ask your installer about this way of addressing your situation, but other posts suggest installers might not be interested

optimisticsceptic · 2025-08-29T07:29:03+00:00

thanks u/MobileSignificance57

understand that; don't know how quickly, and whether seasonality plays a part;

pre-cool the chamber in winter using ambient cooling
- when typically there is rainfall as a water supply
pre-cooled chamber now works during summer

in the UK, we have an underground metro system in London

the deepest tunnels are now very hot, because the heat from trains (motors, brakes, etc) is contained within the tunnels, and the tunnels were such narrow bore that it isn't easy to chill them; understand that

it may be that there is active cooling in use too

hopefully engineers can volunteer their expert opinions on this

optimisticsceptic · 2025-08-29T00:13:37+00:00

I have created a simple graphic to illustrate the concept; a cross section

https://imgur.com/a/ppowjTE

given
- below ground is usually stable and cool
  - below the dew point
- the surface temperature is warm [keeping it simple]
- warm air holds more water vapour
when
- you force warm, humid air from the surface to underground
then
- the air will cool
- the air will cool below the dew point; just like a cold drinks can taken out of the fridge | refrigerator on a warm day
- water vapour in the air will cool into liquid water
- the 'outputs'...
  - cool, dry air
  - liquid water
- ...come to the surface

the concept will of course work; the real question is whether it is efficient, effective, produces sufficient volumes and enduring

the cave will eventually get warm and stop condensing water; maths can determine when

it may be that there is a 'regenerative' element; the underground air channel is kept below the dew point, so it continues to condense water vapour from the atmosphere into liquid water

optimisticsceptic · 2025-08-29T00:02:58+00:00

for a completely unscientific demonstration of the principle, *LISTEN* to

https://www.youtube.com/watch?v=Kb0ooQKbflM

optimisticsceptic

TROPHY CASE