Alan Ambrose

That’s interesting. Having installed my wood burner and had the install passed by BC - each manufacturer publishes detailed data for each model on how close it can be in any particular dimension. I also measured he temperatures after I installed it to double check.

Another option might be to run temporary swa cable from your existing consumer unit via a new breaker/mcb/rcbo/rcb. This can go to a small temporary cu inside the building or a little ‘distribution point’ with a bunch of metalclad sockets. All in a temporary enclosure. Think typical supply for a shed / outbuilding. Probably a job for a friendly sparks.

Would another option be a projector?

>>> I PTFE the thread, with around 21 turns Sorry I don't understand - 21 turns of PTFE on the thread? Max I've ever done was about 5 or 6.

I put the drivers down to a mixture of: + housing economics (i.e a deliberate land shortage) which causes the big developers to make ticky tacky boxes, built to low standard, with the smallest possible rooms and on the smallest possible plots. Yes, they can sell all they make. + largely uncontrollable LPAs who are there to protect the status quo and support the big developers in their aim above - the big developments are the easiest way for the LPAs to meet their targets. + lowest common denominator regs partly for 'affordable housing' which usually means 'low quality' housing. + fairly dumb consumers who until very recently haven't given a fig for energy efficiency and/or how their house is constructed. I probably wouldn't bother to build if I could buy the kind of thing I want.

>>> I wouldn’t consider a failure within 7 years to be fair. Well I wasn't best pleased and my neighbour's water-based UFH lasted 30-odd years - but he has it below a fancy wooden floor, which is so much bother and expense he hasn't actually had it fixed yet. Just a factor of burying stuff in the walls and floors I guess. I don't think there's much wrong with the physics - in general the wattage and temperatures are both quite low. But a little more thought in installation and a quality check on materials would have been helpful.

Hmmm - as two data points - I have a couple of Heatmiser installs using the Heatmiser Zigbee hub and they're fine - one is 80 m^2 (with 5 x neoStat 12v + 4 x neoStat-e + 1 x Wireless Air + UH8-N + NeoHub), one is 180 m^2 with (13 x neoStat-e + 2 x Wireless Air + NeoHub). These are both single floor with typical stud walls, so not as tricky as 2 x concrete floors though. These are the kind with wired power (the signal is Zigbee) so they mostly don't have batteries. All fine except I sometimes lose connection for a few hours to the battery-powered Heatmiser temperature sensors which are outside in weatherproof boxes. FWIW the two systems I have seem pretty reliable. I wonder whether Heatmiser trims the signal output for battery-powered sensors to conserve battery life? Knowing how dodgy RF is, and how busy the spectrum is, and since you don't have that many sensors - is there's a way to run cabled sensors? You wouldn't have to change the batteries then either 😎.

Hmm, maybe measure the temperature in that position when the stove has been going full pelt for a few hours? I'm seeing 50 C numbers from random Googling for 'max temperature for a flat screen TV' - but there will probably be actual data in the datasheet for that particular TV. I know above our stove is 'properly hot'. Maybe some kind of baffle to deflect the hot air might come into the thinking? Actually checking my missive for BC when I installed ours - I was getting 30 C at the wall closest to the top of the stove. So, at that kind of temperature - maybe you might manage to keep the wife happy 😎.

I think with either electric or water-based UFH - in the future, I will interleave at least two cables / pipes in any floor so that if there's a cable fail / leak you can always easily just fallback to one loop.

>>> Failure of electric UFH seems inevitable at some point To be fair, these 3 floors have been running for 7 years without a problem (well, up to this point) and I think the fast warmup of electric is more useful than water-based. Also, if your water-based UFH has a leak (my neighbour's did) then you have an equally tricky problem to solve. I personally wouldn't rule it out again. But If I did this again, I would be more careful (as above) and I would also pay more attention to the thickness of the insulation underneath, .

>>> I've just had a 10k NTC fail so make sure your sensors whatever they are can be replaced or install spares. Yeah, that's not the only mode of failure. I have one floor where the heating element has gone kaput a few weeks ago. I will investigate further but it almost certainly means taking up a resin floor, the UFH and the insulation underneath and relaying the lot from scratch. About the only difference between this and the two other electric UFH floors in this place is that a couple of years ago this floor overheated (not too badly but the floor was noticeably hot) when something in the utility cupboard pressed against the thermostat buttons. The floor had two spare thermistors laid under it for backup, but the existing thermistor was fine - it was the heating loop that is open-circuit. So, I would bear in mind possible failure of the heating wire. If and when I replace this lot, I have made a mental note to do the following: + try and ensure the controller is hardware fail safe. + prefer proportional over bang-bang control to reduce electrical stress. + check the provenance of the heating wire more thoroughly - it could be (duh) that not all heating wire is equal. + maybe lay two separate heating wires as well as multiple thermistors so there are ample backup circuits. I would be very cautious about having the control loop via automation software rather than a close loop in a dedicated thermostat / hardware controller. If I did choose to go down the automation route I would want some kind of local temperature trip as a backup.

A further update: + the API seems to work fairly reliably. + it's not so well designed or documented: for instance - although the app (and presumably the hub) knows the detailed 'heat-on' schedule by device over time for the couple of months on a 15 minute grid ... the api seems to only give you the number of total hours per day (as a rounded integer) per device for the last week. + however there a bunch of large json blobs you can retrieve, including 'GET_LIVE_DATA' which returns a 23K byte blob, 'GET_TEMPLOG' which returns a 5KB blob per device etc. + you can also send commands too. So this is, for instance, how the home automation systems integrate with the hub.

>>> It does rely on data collection, which everyone should be doing anyway. True - but if you are electric and/or gas heated and have smart meter(s) this could be, say, bright app daily data power usage download vs. local weather station average daily temperature or heating degree days from https://www.degreedays.net/.

>>> if the assessment point is invisible from the unit (and 250mm either side of the unit) then it gives a 10dB attenuation. A sheet of paper or a bin bag maybe 😎.

>>> got 3phase smart meter installed after 6 months of trying Well good luck. Goodness, we're drowning in treacle here. I had another go today with Eon call centre: Me: Is it possible to check on this 3-phase meter install again as it’s now two months since I first asked? If it’s not possible maybe you can let me know. Eon: Yes, it possible to install 3- phase meter. If there is anything else you will need, do not hesitate to contact me. Me: Just to be clear, over the last two months you guys have been unable to book an appointment to have one fitted. Could you please make one last attempt to book an appointment. Eon: I just need to ask a few questions, just so the engineers are fully prepared... Me: I already answered similar questions on 15th November, but see the same answers below... - I'm not sure whether it's more Kafka or Brecht or Beckett. Presumably the call centres get paid by the word. As they say - just because you're not paranoid doesn't mean they're not out to get you.

OK basic access kinda works:

Also: https://github.com/MindrustUK/Heatmiser-for-home-assistant https://www.openhab.org/addons/bindings/neohub/ The latter is useful as it describes how you configure the hub with recent firmware (I think they update the firmware OTA automatically) for socket comms: (a) update the mobile app and set 'Legacy API' on in settings. (b) identify the hub ip using a scantool / your router's dhcp map and then check with nmap or similar that port 4242 is open. Then code something like the stackoverflow link above will work - otherwise you get 'socket closed'.

>>> I'm considering getting a NeoHub so I can use the API it exposes me too and it just surfaced on my stack again (could be only for 10 minutes). Let me note some finds on this subject then: https://stackoverflow.com/questions/57873516/trying-to-communicate-with-heatmiser-neohub-using-provided-api-json-over-tcp-an https://github.com/RJ/heatmiser-neohub.py https://faq.heatmiser.com/hc/en-us/articles/360001844820-How-do-I-request-the-API-Documents- https://pub.dev/documentation/neohub/latest/ https://gitlab.com/afshar-oss/neohub-dart/-/blob/master/doc/Neohub_Api_For_Systems_Developers.pdf I'll post here if I find any time to write some code...

@jayc89 >>> I'm considering getting a NeoHub so I can use the API it exposes Can I ask - did you do that in the end?

I just noticed that there's a good way to measure actual overall U factor / energy/degree day described here: https://forum.buildhub.org.uk/blogs/entry/965-update-on-energy-use-based-on-4-years-of-actuals/?tab=comments#comment-6148 See TerryE's post where he uses a regression of daily energy used vs. external temperature: Returning to the data, the strongest trend is shown by the external temp vs daily total power use scatter plot, which fits to P = 60 - 2.45T, that is each drop of 1 °C in average daily outside temperature requires an extra 2.45 kWh heating. I also checked this against my pre-build design calcs which predicted 1.92 kWh, i.e. the as-built house performs about 25-30% worse than as-designed.

Well I think this is a very good discussion as a bunch of us are likely to face similar hurdles. While I generally like to be squeaky clean, I think in this case the LPA/MCS/BSI systems are a bit stacked against you, so a bit of street smarts are required. How about these tactics: (1) Install + Inform the neighbours of your plans and tell them you'll taking great pains to observe the noise rules. + Install as planned. Have a backup plan for extra attenuation / screening if needed/desired. + Make some measurements yourself before/after installation along the MCS/BSI lines. I like the time graphs for their sciency look and feel, and that suggests a logging noise meter/app. + Tell the LPA the work is done as specified. If they ask you for the calcs/data, submit them. + Check with the neighbours after installation to make sure they're happy. (They're the only ones really who have the ability to spark up the LPA). That should be it. However, if, despite your careful handling of the neighbours they raise a complaint to the LPA: (2) Argue and remediate if necessary. + Submit and/or point the LPA to your calcs/data. + The neighbours/LPA will either have to put a consultant to work through your calcs/data or employ one of their own to make their own measurements. Bearing in mind the most LPA's are stretched right now and their general remit is to encourage energy efficiency (e.g. heat pumps) either of these IMO is very unlikely. + If the neighbours / LPA get the bit between their teeth. Then: (a) ask them to identify the errors in your calcs / methodology. (b) propose your back plan for attentuation. (c) if and only if that is accepted, implement your backup plan. That should be it, but if there are still objections: (3) Circle the waggons. + make updated measurements yourself and submit your updated data/calcs. + If either of the neighbours / LPA still have the bit between their teeth, then I suggest they'll need to prove non-compliance (and you've already demonstrated that you've done everything in your power to comply). + if they can prove non-compliance and you can't think of any other attenuation mechanisms, go to appeal. + plead (a) you have taken every possible step to comply, and (b) heat pumps are government recommended technology. + if you lose, take it to the papers and embarrass the LPA. It's BS that you even have to think this through, of course. I would be willing to bet that you'll easily stop at (1) above. In my view, LPAs are in an Alice in Wonderland state atm. How does that sound?

>>> Pretty much everything else eventually heats the house fabric. Yeah, agree. Thanks for the very useful analysis and stats. 11.4 MWh p.a. does sound high. What's the floor area? Since you're obviously a fellow technologist - maybe time for a circuit monitoring set-up?

>>> The rating level of noise emitted from the air source heat pump (ASHP) system hereby approved shall not exceed 10dB below the existing background noise level as measured or calculated at 1 metre from the façade of the nearest noise sensitive property. The measurement and assessment shall be made according to BS 4142:2014+A1:2019 'Methods for rating and assessing industrial and commercial sound' at the nearest and / or most affected noise sensitive premises, with the ASHP system operating at maximum capacity and be inclusive of any penalty for tonal, impulsive or other distinctive acoustic characteristics. I'm not so sure it wouldn't pass the regs they have cited. It should be easy for an acoustics person to figure out from: + the actual noise of the unit (which should be in the manufacturer's spec).. + the actual level of background noise. + the distance to the neighbour's place. + any intermediate barriers. Or you can just try putting a fake noise source with the right noise level in the right place (maybe a phone with a recording with or without a USB speaker) and hotfooting it over to the neighbour's place with (in the first instance) a phone app or a cheap dB meter. Then measure the noise level with and without the noise source on. Voila, a first cut estimate. That'll tell you whether you're easily within / way over / or on the borderline. While you're at it you can even ask the neighbours to do a mark one earhole test. If they're not happy, you can chat about noise screening measures. Some more facts would be useful e.g. the answers to the points above.

Nice, useful when your offspring have skills . Maybe you could ask him what the standard means in terms of limit in dB over background?

A bit nonsense that the BSI standard is so expensive, but funnily enough it's available on the Warrington district's site for free: https://www.warrington.gov.uk/sites/default/files/2020-08/cf54_bs_4142_2014_a1_2019.pdf All that mumbo jumbo (somebody has really gone to town) means essentially measure the background noise level and then with the heat pump running. Obviously the heat pump can't add too much, otherwise it's 'officially annoying'. Essentially you're just measuring how much the sound level increases when you turn your heat pump on. Not sure you really need some consultants for that - it would be good if you can just use a cheap sound meter or even a phone app. Maybe if you can provide a graph like in the BSI doc then you'll be good.