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dnb

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dnb last won the day on December 31 2020

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  • About Me
    Building a SIPS panel house on the Isle of Wight, in the muddiest swamp I could find.
    Just call me Shrek!
  • Location
    Isle of Wight

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  1. Given the amount of time at work this week I have spent in SHE related refresher courses instead of being out in the sun doing "dangerous" things on my building site, I'm going with "No". And I share the OP's pain with non-linear ADCs. Dropping the sample rate (if Nyquist will let you) can help sometimes. But mostly not
  2. The point I was trying to get across is that I have a policy already and am 2/3rds through my build yet they appear to be trying to change the rules.
  3. Has anyone else with an LABC Warranty had a communication essentially asking for a premium increase? As far as I can see they have changed their internal workings and are now trying to claw more premium out of existing customers who are not yet complete.
  4. You haven't met the wife. Or been subject to her threat of dire consequence if the hot water should ever stop her having a bath. ? They are quoting 65 deg C for charging with heat pump and 75 deg C for boilers, so guessing "not really" for that.
  5. There is nothing like making a plan and sticking to it, is there? And it's a bit of fun for a quiet Saturday after long week of software testing, 1st fix wiring and plasterboarding. I originally planned to fit a large water based thermal store but since the 4th gen Sumamps appeared and the control system "gremlins" appear to be resolved maybe it is time to reconsider the plan. Nothing in the house has got to the stage of preventing such a plan change. I know the new Sunamps have only been around for a few months, but does anyone have one (any size) that's currently in use? The choices of new Sunamp are a little odd. Why so many different options for very similar prices? e.g. what does the "ePV" do that the "e" doesn't given that you need an external PV diverter? I suspect the answer is that there is no difference in hardware other than volume of PCM but the controller has some different parameters. I've developed a Matlab model of hot water use based on a Monte Carlo simulation of 100 years of random usage of hot water given some parameters e.g. occupancy and sizes of bath etc. This indicates we will on average need 18kWh of hot water energy per day, with a fairly tight standard deviation. I suspect the mean is an over estimate but it does align fairly well with the gas usage for the past few summers (i.e. when the bill is DHW only). I have used the model to find the ideal number of solar PV panels based on payback time for the roof (although I didn't forecast energy prices rising quite as quickly) so I have a 6.5kW system that should yeild 7000kWh per year. At face value the usage model indicates that the house should have 2x 9kWh Sunamps. This gives the right amount of hotness per day on average based on one "charge" per day and sufficient immersion heater wattage to use most of the solar power but two sunamps is an expensive option, and there are actually two "charge" opportunities most days - over night and during the day. So perhaps we could just have one of the 12kWh versions? I put a bit more effort into the model and made it generate annual costs for a 12kWh store and an 18kWh store (assuming low standing losses - way better than the thermal store case) and get the following charts: For the 12wKh case, average running costs are £770 per year for importing electricity from the chart on the left using the random usage model and the random solar irradiance model. The chart on the right is the amount of solar PV not used for DHW so is in theory available for other house uses should they happen to line up in time. (No surprise that the numbers are similar when the PV provides 7000kWh over a year and the DHW requirement seems to be around 6500kWh.). This run of the model assumes we implement a scheme to put heat into the Sunamp via the solar PV driving an immersion heater external to it - e.g. something like subverting a Willis heater driving an UFH heating loop I like this idea since it is very simple, especially if the Sunamp internal heaters are difficult to drive - they only appear to work with the Eddi controller that doesn't appear to work properly with my PV array since it's too big. Does anyone know details of this? The next chart shows one year from the simulation illustrating key performance measures. Waste is where the system uses grid electricity when it was sunny the next day and the store wouldn't have been emptied by the days usage. Excess PV is obvious. Input shows grid electicity use. The store values show the contents of the store at 6AM and 8PM for each day. The fact that they sit at a constant level indicates that the store might be a bit small. This is the 18kWh case. Yearly running costs are down by £300/year. So the second Sunamp will break even after around 6 years at current usage unless the excess PV was actually being used extremely efficiently. A year from the 18kWh store case. The parameters are the same as before, but now note that there is an excess of storage so the PV use can be more easily managed - waste is considerably reduced. Increasing the amount of storage beyond 18kWh results in dimishing returns as is no doubt fairly obvious. A 24kWh test shows imported electricity cost drops to £320 per year, but given the cost of a Sunamp doesn't seem particularly linear it might be a good option. That's tonight's analysis job. All in all a Sunamp solution compares well with the 500 litre thermal store - standing losses are much easier to manage and I can make considerable savings in not implementing an extremely well insulated cupboard for it. But this doesn't quite get me to the point where a Sunamp is only a small capital cost increase. More research is needed to create a viable solution - has anyone got two running in parallel? Did it present difficulties?
  6. Yes. We have one too. While it makes excellent hot chocolate I find it a bit hit and miss for the frothy milk. And ours is getting old now so it takes its time... Agreed coffee is the priority. I do like a morning cappuccino.
  7. I have a work award payment of £500 I need to spend fairly swiftly. Taking it as cash isn't an option. I could do something practical with it - like buy the Cordek for the garage foundations or another pallet of plasterboard - but I think I would like to have something I wouldn't normally think about buying. My Aeropress is good at work and my 25 year old stove top pot still works... but I would like a decent milk steamer and I never usually have time to make coffee at home on a work/school run morning so I would like something that can do most of the work for me, maybe apart from steaming the milk - I don't mind doing this because it won't be a feature used every day. (Instant is not an option. Ever. Just NO.) Any suggestions or recomendations as to which machines are worth having? I don't think the boss at home will allow much budget creep, so please avoid £1000+ machines... I would like to live long enough to see the house finished! Thanks
  8. Hi @BrettW Happy to bore you half to death with talk of self builds! Need to do a couple of updates on the blog for the internal fit and the latest window issues... I'm an import - can't call myself an "Islander" according to the local rules. ? Keep looking. It took us a couple of years to get a plot. Try to get as much done in advance as you can so that you can move quickly on any plots. Scour the property websites as often as possible and be prepared to move disturbingly quickly if it feels right. We offered on ours the day it appeared on right move.
  9. The surveys can easily get out of hand. Good luck with it @nod I did similar to @joe90 with rewriting sections of my survey as the tree protection plan. I ran it past the tree surgeon that did the survey (paid him a token amount in addition to a tree removal job I didn't have the skills and equipment to do myself) because the trees in question were of significant value to me - all oak and some significant in size. It is certainly possible to do it yourself to a good enough standard. As previously mentioned, proped Heras fencing covers most ills. But make sure in the document you mention the tree root protection zone signage for the fencing (and give an example as an appendix). In short, we had all the required information in the survey and other planning documents, but it was not presented as a document in its own right - I think that is one of the issues with certainly my planning department - they distribute the information thinly so the tree chap doesn't have to read about highways etc. But the problem is that then the tree document then may have to contain the bits of the highways document in order to make sense. I got caught out by this when I kept getting asked questions that I had already answered by referencing other submitted documents.
  10. I will notice! And as far as it goes, that is enough. What, practically, is the performance difference between 1 and 2 sheets of board with resilient bar? 1dB or 3dB or more? And from what point? 1dB more attenuation from 30dB is worth having. But 1dB extra from say 55 or 60dB hardly seems worth it in a house. (BTW I do understand dBs.)
  11. Ceiling height is a minor concern - some rooms will start to look letterboxy, and the other is loading on the joists. My preference is bar and single board if it will work. Neither are significant i admit I saw the silent floor in the book but can't do it since the floor is already bonded to the joists as part of the sips kit build. I can however use an acoustic underlay of some description over the floor, appreciating that it will not be as good.
  12. Thanks all. I think @SteamyTea and @dpmiller have it cornered. True isolation of supply isn't required since I think I can use a switched fcu for that - it won't be in an inappropriate zone itself. It just doesn't need wifi. No need to congest the spectrum more than necessary. We have enough wifi devices already.
  13. I am trying to understand what to do for my ceilings. I have consulted the white book and have two options that seem practical. Double board with 12.5mm or single 12.5 board on to resilient bar. Both will be going on to steico joists and have 100mm (unless i can get away with 50mm) acoustic insulation. I would like to know how either scheme works in real life because so often lab tests aren't totally representative.
  14. Are there any similar devices to the Shelly Plus 1 that don't have wifi? I have a very simple problem to solve that won't be enhanced by wifi. I need a small relay device that can sit in a metal 1 gang back box behind a fused connection unit to control a 240v 300W load based on a 24v DC signal (could make 12v work too). Obviously the Shelly device will do this quite well for a reasonable price, but surely there's something simpler out there that doesn't need me to get my soldering iron out... Found loads of DIN rail relay units but these don't suit the location.
  15. No. Not a better answer. Putting someone like me in charge of anything usually results in some kind of disaster... We do, however, need a process to combat such organizations when it becomes clear to all outside that it now mostly exists to forward the organisation itself and not the thing it was originally created to achieve. This is usually frowned upon because it usually costs jobs. Regarding the original point of dealing with this legislation by removing the wildlife before putting in planning - it's already happening with the scheme we have. I know I looked at my land very carefully before submitting planning. I didn't do anything other than removing lelandii trees that were far too big and a diseased oak stump though. I am fairly sure that I definitely have not aided bidiversity. I couldn't even stop my woodpeckers from destroying the bat boxes I put up to satisfy a planning condition.
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