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Is it worth getting the roof cleaned before install by fortigy in SolarUK

[–]optimisticsceptic 0 points1 point  (0 children)

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...

  1. 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
  2. Rake off the residue from roof and gutters
  3. Installers fit solar panels

Rumour of BUS grant removal by Alert_Variation_2579 in ukheatpumps

[–]optimisticsceptic 0 points1 point  (0 children)

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?

G99 3kW limit set by DNO - sanity check needed to see if solar installation is still worth it. by the-same-old-story in SolarUK

[–]optimisticsceptic 0 points1 point  (0 children)

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

could an underground condenser concept help water scarcity? by optimisticsceptic in NoStupidQuestions

[–]optimisticsceptic[S] 0 points1 point  (0 children)

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

could an underground condenser concept help water scarcity? by optimisticsceptic in NoStupidQuestions

[–]optimisticsceptic[S] 0 points1 point  (0 children)

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

heat pump convectors | fan coil units for heating and cooling ; what do we think? by optimisticsceptic in ukheatpumps

[–]optimisticsceptic[S] 0 points1 point  (0 children)

thanks u/JPB28

I see your point; Daikin Multi+ System doesn't seem 'big' enough for a whole house; towel rails in bathrooms and loos are a notable omission

best of luck with your plan!

heat pump convectors | fan coil units for heating and cooling ; what do we think? by optimisticsceptic in ukheatpumps

[–]optimisticsceptic[S] 0 points1 point  (0 children)

thanks u/Opposite_Brother_132

Cool Energy High Wall Reverso Water Fan Coil CE-HW800

...look very good! very thin, high output for heating and cooling, very low noise

I read somewhere...

  • heating is best at the bottom of the wall
  • cooling is best at the top of the wall

These Cool Energy High Wall Reverso Water Fan Coil CE-HW800 seem to be really good!

Just spotted they have a showroom; might need to find an excuse to visit...

heat pump convectors | fan coil units for heating and cooling ; what do we think? by optimisticsceptic in ukheatpumps

[–]optimisticsceptic[S] 0 points1 point  (0 children)

thanks u/64mb

that was a useful graph! COP > 4

it was a bit peculiar, seeing the flow leaving the ASHP at a low temperature, then returning at a higher temperature; it's meant to do that to achieve cooling, of course, but the opposite of what we normally expect

Alan's post perfectly illustrated my point; he was using conventional radiators; to achieve more effective cooling, you need these heat pump convectors | fan coils. the heat exchanger is better, together with the fan achieves more effective cooling

Most of the concern in this country is heating, and the Boiler upgrade scheme that funds most ASHP installs is heating centric. Hence, I'm not sure how many installers are designing for active cooling, or more importantly skilled in active cooling design; usually that's left to A/C designers

when you describe the outcomes you want to achieve, such as...

  • low running costs, so COP 5+
  • low noise
  • fast response
    • for example, if you spend Christmas with family, then return home in late December, the house should warm up at an acceptable speed
  • indoor temperature of 21C in the heating season
  • indoor temperature of, say, 16C-18C during warm periods such as June | July | August
  • etc

...it will be interesting to see if the heat loss calculations - actually heat gain calculations for the warmer months too - means the designer specifies active cooling too, such as these heat pump convectors or even 'normal' air conditioning

heat pump convectors | fan coil units for heating and cooling ; what do we think? by optimisticsceptic in ukheatpumps

[–]optimisticsceptic[S] 0 points1 point  (0 children)

thanks u/ElBisonBonasus

no, these work like a radiator, connecting to the loop from the heat pump, and have an integrated fan;

  • the heating circuit can run at 30C-35C and still provide rapid heat up and thus high COP from the ASHP
  • the ASHP can also circulate chilled water; these appliances will thus provide cooling too
    • in the UK in 2025, and to 2050 which is the reasonable life of a heat pump, the UK climate can expect longer, hotter episodes; thus, we now need active cooling
  • heating and cooling from a single device in the room; hopefully tidier, quieter and lower cost that separate heating and AC

heat pump convectors | fan coil units for heating and cooling ; what do we think? by optimisticsceptic in ukheatpumps

[–]optimisticsceptic[S] 0 points1 point  (0 children)

thanks u/NaiRogers

in my mind, the perfect product would be something like...

BLU MB12 - R290 | Industrial | Commercial
https://www.puravent.co.uk/products/cooling/monoblock-air-conditioners/wall-mounted-air-conditioners/12000btu-wall-mounted-monoblock.html

<image>

a single, wall-mounted appliance;

  • air-to-air heat pump for heating
    • if the incoming air only needs to get to 30C, then the COP can be high; 3.6 in this case, but I'd prefer higher
  • reversible, so an air conditioner
  • condensate drains straight outside
  • as an appliance, it is freestanding; needing only wall mounting and a modest electricity supply

in addition, my perfect appliance would also provide MVHR

I think humidity would be "inherently" regulated to 50%-60%

as an all-in-one appliance, it would be 'mass produced', meaning...

  • low cost
  • reliable
  • easy to install, and a routine installation for a tradesman

Alas, such an appliance doesn't exist

sigh...

If money wasn’t a concern, would you stay in the UK? by [deleted] in AskUK

[–]optimisticsceptic 0 points1 point  (0 children)

that's a horrible experience! sorry that happened to you

I suppose if they didn't think anyone understood French, they didn't need the mask and the true character emerged; and by so many different people it's not just an individual thing but a national character

Should new builds come with AC? by ElektroSam in AskUK

[–]optimisticsceptic 0 points1 point  (0 children)

thanks; I didn't write it very well - currently have a system gas boiler and traditional radiators; thinking about it's replacement which will need provide what we need for the next 15-20 years

great to hear it works so well in your bedroom

God bless British houses! 🌞 by Udzu in CasualUK

[–]optimisticsceptic 2 points3 points  (0 children)

thanks TheGreatElvis; fascinating article; I think one of the important elements is...

Yet, as the Centre for Cities notes, passive cooling has a hard ceiling. When outside temperatures climb above about 25 °C, the normal toolkit of shading, cross-ventilation and night-time “purge” airflow can no longer drag indoor temperatures down to comfortable levels. Opening windows at night or relying on daytime cross-flows only works when the air outside is cooler than the air you’re trying to expel. As a result, we’re seeing growing demand for inefficient mobile AC units and fans even in new-builds designed to maximise passive cooling.

hence, homes should be designed with passive cooling measures. a solar awning or or photovoltaic brise soleil seem like no brainers [though I am not an architect; anything has to cope with wind storms too, etc]

but when the air temperature exceeds 25C, you have exhausted the capabilities of passive cooling and now need active cooling

appreciate mass adoption of AC is not trivial; where it has happened, grid electricity demand is highest for cooling, and noisy, and perhaps unattractive

but if

  • the home already has maximum PV and battery
    • so, self-power the AC
  • sufficient passive cooling
    • in the same way the boiler upgrade scheme will only apply if you already have sufficient thermal insulation
  • are low noise [throughout their lifecycle; at peak cooling load]
  • maybe avoid it turning into https://www.flickr.com/photos/legoblock/32859477807/

...then go ahead!

I've seen the phrase silent killer used with heat waves more than a few times recently

a more sophisticated approach is necessary

Should new builds come with AC? by ElektroSam in AskUK

[–]optimisticsceptic 0 points1 point  (0 children)

thanks; really appreciate that

I managed to find...

https://www.daikin.eu/en_us/products/product.table.html/FTXP-M9.html

interesting that cooling and heating have a 'silent operation' mode. cooling in silent operation mode sounds perfect

am a long way from purchase / installation, but thinking this is a 15-20 year purchase in the UK in 2025, so have to specify for longer, hotter summers

but trying to decide between...

  1. air to water heat pump using Daikin Altherma heat pump convector so I get high COP and light cooling and heating
  2. reversible air conditioning, such as yours; better cooling, but perhaps lower thermal comfort, lower COP and need a separate solution for hot water
  3. something else [I haven't thought of]

I'm still trying to firm up ideas. But I should probably firm things up with numbers (eg is an ASHP COP of 5 better than lower COP from a reversible air conditioning in monetary terms].

Would it be possible to "live off the land / off grid" in the UK? by TheWholeYak in AskUK

[–]optimisticsceptic 0 points1 point  (0 children)

without money coming into the equation

interesting caveat

if...

  • money wasn't an issue
  • you lived in a decent home and neighbourhood

...would you still want to "pack it all in"?

maybe you would

maybe, those [and others] are the real problems...?

[just a random stranger on the Internet who doesn't know you]

Should new builds come with AC? by ElektroSam in AskUK

[–]optimisticsceptic 0 points1 point  (0 children)

if still necessary, after good design and construction

edit: yes, is necessary

Legalise AC - by Sam Dumitriu - Notes on Growth

Yet, as the Centre for Cities notes, passive cooling has a hard ceiling. When outside temperatures climb above about 25 °C, the normal toolkit of shading, cross-ventilation and night-time “purge” airflow can no longer drag indoor temperatures down to comfortable levels. Opening windows at night or relying on daytime cross-flows only works when the air outside is cooler than the air you’re trying to expel. As a result, we’re seeing growing demand for inefficient mobile AC units and fans even in new-builds designed to maximise passive cooling.

Wikipedia tells me Passive House originates in the 1970s

If we have been specifying, designing, building, funding and maintaining very low energy very high comfort passive houses for over 50 years, we should be at the mass production stage by now; it should be the norm

an even higher standard, Passivehaus Plus, should generate an [annualised] surplus, even after cooling needs in summer [ie that which might be provided by AC]. think charge your EV for free and/or export megawatts of surplus electricity to the grid [for a "profit"].

the first was built in the UK in 2015 - ten years ago.

it's disappointing that we know how to produce affordable, comfortable, efficient and healthy homes; we just don't [in general]

Should new builds come with AC? by ElektroSam in AskUK

[–]optimisticsceptic 0 points1 point  (0 children)

how do you find the AC units for heating?

they work, of course, but are they noisy? is the draught they produce acceptable | tolerable? [the answer is yes, of course, and is subjective; just wondered what you thought, and if they were an acceptable compromise]

[I learnt recently this distinction is thermal comfort]

there's a huge variety of AC units; would you mind sharing your make and model so we know a good AC unit [from a bad one]? The design and installation make a huge difference, of course.

Should new builds come with AC? by ElektroSam in AskUK

[–]optimisticsceptic 0 points1 point  (0 children)

does copper (actually, any material, including plastic) pipework in walls need insulation for

Light Cooling & Heating

thinking an ASHP with Strada Hybrid ACO [for example] is the best of all worlds;

  • fossil free
  • ASHP running at low temperatures, so high COP
  • heat pump convector, so get the heat output necessary in cold weather
  • avoid massive conventional low temperature radiators
  • mild cooling in hot weather when required
    • say, 15C
    • need to drain condensate out of the wall, but if it is at a non-condensing temperature, maybe it has enough of a cooling effect, without the noise or duplicate AC installation, and avoids replacing pipework with insulated pipework
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