sgt_woulds

In a normal situation with BSS kettles, ovens, immersions, etc would run off the solar and battery with grid backup if there is too much demand and the battery would be depleted well below 95%. It also wouldn't immediately recharge to 95% after use. Thus it would be in a more depleted state towards the evening with normal use case and charging profile. Perhaps I'm not understanding your setup correctly, but it sounds like you are not letting the battery drop below 95% during sun hours or overnight when it charges on E7? How many hours in a day will it deplete below 50% or complete a full cycle from 20-80%?

Are those single-insulated tails? (Blue and Brown cables) If so, they need additional mechanical protection to comply with wiring regs. Diverters are prone to failure after a few years - they are normally fitted in airing cupboards without airflow - heat soaking of components is probably a factor in the failure rates. The most robust units we fitted were the Solic 200 (Designed by an ex-MOD engineer - bulletproof) without bells and whistles or 'smart stuff' going on. From your description, once the battery tops up, and the underfloor is up to temperature, the immersion kicks in at full whack. If PV is not producing enough to supply the full rated power of the immersion, (and other loads in the house) the battery kicks in to supply the rest? If this situation continues for a period of time then battery drops below 95%, immersion switches off and goes back to charging the battery. In this scenario, the battery is discharging and recharging a lot at the top end of its capacity. Have you discussed this with the manufacturer and are they happy to maintain the warranty in this scenario? The last 20% of charging on Lithium cells creates heat and internal resistance - depending on the chemistry this will put a lot of stress on the cells and shorten the life expectancy. When we were running a fleet of 4 Nissan E-NV 200, half the vehicles were charged to 100% regularly but then discharged, (driven!) until at least 20% before a full recharge cycle. After 2 years battery health was very good, with no loss of range (140 miles indicated on the GoM but 100 miles max in RW use with load - 80 miles average per day with at least 400 kg in the back). The other vans never dropped below 75% SOC and were constantly topped back up to 95-100%, (short infrequent road trips with same loading). After 2 years the range had reduced in RW use to 80 miles max. I realise the chemistry, scenario and stress is different for a vehicle compared to a static battery but I'd be surprised if you'll achieve maximum life expectancy with this regime - which could cost a lot more in the long run than replacing diverters. Please keep us updated - it would be useful to know how this works after a couple of years as it is an interesting setup.

Heat pumps with sound-proofing measures. If that costs more, so be it. I chose to insulate and seal my property properly instead to reduce the need for heating. I used natural insulations as they were better for me, my house, and the planet. These are much more expensive than oil or mineral-based insulations and I paid the premium without expecting anyone else to contribute, just because I want to 'Save the Planet'. If your solution costs more to implement without nuisance to the environment and others then you should pay the premium - because you want to save the planet too. The oil companies have got away with all the pollution and harm they cause because that is 'just what happens in the process of extracting and using fossil fuels'. We should just put up with this, 'cos that's just how it is and has always been? The world is crowded and noisy. We should just put up with this too? Modern technology should reduce harms without introducing new ones. I wonder what the OP is making of the social aspects of our discussion? 🙂

Yes, the world is noisy - the effects are cumulative - please don't add to it! In most of the mass-produced housing estates with pocket handkerchief gardens all cheek-by-jowl a HP in every garden where you can never get more than a few meters away would be intolerable at 42 Db for most people who just want to relax quietly in their own little bit of space. Tractors are intermittent noise. HP are daily scheduled nuisances. I cannot comment much about wind turbines as although we live about 6 miles from a couple we can never hear them.

There's a 42 decibel limit at the neighbour's property, legally enforceable. Which is above the point at which many medical and science papers state is harmful.

Why is that not good enough - why has BS8233 acceptable for everything else but not for heat pumps? Because this was written by people who didn't have to live with the noise and without consultation with the public at large.

Exactly. I visited one of our solar customers who was an early adopter of GSHP. (it didn't work as it was undersized, but that is a whole other bag of fish...) This was one of the quieter pumps I've heard but sitting outside her cottage enjoying a cup of tea in rural Oxfordshire it could be clearly heard. She built a hit and miss enclosure out of clay lump and wattle and daube panels and trained ivy up the up the side nearest the house. Made it effectively silent for my next visit half a year later. I was involved in a project installing solar PV noise reduction road barriers for a short section of motorway on the south coast. The difference this made to very loud traffic noise a couple of yards behind it was dramatic. Imagine what could be done with a much quieter noise source like a heat pump. To modify my earlier statement: The problem is respect for others and a bit of extra effort, not physics...

Not at all. This would curb the idiots with loud exhausts, etc. Stationary / crawling traffic is mostly about engine noise. People living on high-traffic streets should welcome mass adoption of EV's. As I've said myself, distant road noise is mostly about tyre friction and air movement and these are both being improved by manufacturers driven by the move to electric vehicles. Quieter cars drive NVH reduction, of which tyres are a major cause. New compounds and carcasses are being developed to reduce friction and resonant noise in tyres. Vehicle Cd figures will also improve to maximise range and this will also reduce wind noise.

I'm assuming you aren't including me as one of the denialists? The problem is not debated - the solution is! My objection is to noise pollution, not heat pumps. A properly noise-attenuated housing is fundamentally possible. The problem is cost, not physics...

Tough Buttercup - a couple for starters 🙂 For Humans: How Different Sound Levels Can Affect You - Noise Project - not section on dB ranges and effects - 40-50 dB range is where most problems start - the same range as most ASHP Noise Pollution Isn’t Just Annoying — It’s Bad for Your Health (brainfacts.org) Noise and mental health: evidence, mechanisms, and consequences | Journal of Exposure Science & Environmental Epidemiology (nature.com) The Effect of Noise Exposure on Cognitive Performance and Brain Activity Patterns - PMC (nih.gov) Crosstalk between Oxidative Stress and Inflammation Caused by Noise and Air Pollution—Implications for Neurodegenerative Diseases (mdpi.com) For Wildlife: Evidence of the impact of noise pollution on biodiversity: a systematic map | Environmental Evidence | Full Text (biomedcentral.com) Frontiers | How chronic anthropogenic noise can affect wildlife communities (frontiersin.org) Songbirds affected by human noise pollution | Interviews | Naked Scientists (thenakedscientists.com) Anthropogenic noise affects insect and arachnid behavior, thus changing interactions within and between species - ScienceDirect

" In the vast majority of cases the noise is no more than (and frequently a lot less than, any of these things we are all very much used to and accept. " Change that to: 'things we are forced to listen to and aren't given a choice about'... There is a very real difference between noise that is natural and that living creatures have evolved with, and continuous artificial noises. It creates low-level stress which raises blood pressure and increases inflammation leading to long-term medical conditions. Road noise is truly awful - I really looking forward to the mass adoption of EV's as this will reduce considerably - although a large proportion of the noise we hear at a distance is tyre roar and air displacement. If cars had only been invented last week people would be up in arms about the stink and hubbub - sound barriers would be imposed on every road. We should learn from our mistakes with future technologies, not add to the problem. The real solution, (until ASHP noise attenuation is improved) is building / upgrading to good standards and using MVHR with heating - keeping any associated noise inside the building envelope.

No fear of change. ASHP is a great technology that needs to be refined to remove the annoyance to others. I fully agree that it needs to be rolled out as quickly as possible - but not in it's current form. Electric cars are great, noise is reduced to tyre friction and a low hum. Then some people say they need to make more noise as people cannot hear them coming so the noise pollution is built back into them! I'm glad you want to save the planet - I do too. But I don't want to hear you do it...

Also, the comment about the boiler on the landing - agreed it's a bad choice. But at least it is their noise and they are keeping it to themselves. Fitting mechanical plant that creates noise that others can hear is just as antisocial as playing music on your phone in a public space.

The quiet ones aren't quiet. I don't want to sit on my garden bench and listen to a fridge running on the other side of my fence. It's only a quiet whooshing, but it is noticeable at all times when it is running. Or should I say, when it switches off you suddenly realise how noisy it was. This kind of low-level background noise is proven to increase stress in both animals and wildlife. The majority of heat pumps (GS & AS) that I've come across over the years are not as quiet as my neighbours. Also, as they age they get noisier and generally people won't repair things until they fail or are legally obliged to. The world is noisy enough. Make them quiet enough that I can't hear them when I'm sat on them and introduce a legal noise testing regime, then, and only then will they be acceptable.

Scaffold Canopy is expensive. Scaffolders will need to ballast / secure and provide certification and calculations, (and insurance) to cover the additional risk of building a giant wing on your house. Requires far more bodies, or fewer people but more days to complete. External sheeting is also essentially a consumable as it gets bashed to buggery in all the '100 year storms' we have these days. You are paying extra upfront for convenience and speed for the rest of the works. I doubt you'll find it much cheaper from a reputable scaffold company. There are still some monkey scaff companies around if you want it cheap - you pays your money and takes your own risks.