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As promised a little update on the Battery Storage. Firstly i'm very glad I bought when I did, as everything battery storage wise has skyrocketed in price since, even the prospect of adding a US2000C seems unlikely for now, though to be honest, going on my usage I don't think it would add a great deal of benefit. So I'm running the Solis 5th Generation AC Coupled Inverter, which does have a couple of niggles, which at present are reducing its savings potential. Those issues are: Whenever the battery isn't at 100% SOC, it pulls an amount of power from the grid, somewhere between 60W and 100W Even when the battery is actively charging, it still pulls the same 60-100W from the grid, regardless if there is enough PV power to charge the battery and cover loads at the same time. Once the battery is 100% SOC and im generating PV more than my load, I import 0W. Pulsating loads (such as induction hob) the unit can find hard to track, due to their pulsing nature, and the delay in reading the CT clamp and acting upon it. Now my base load is around 45W, so that means that since i've had the battery, i'm actually consuming more during the nighttime than i did previously, which is a negative. I got in touch with Solis UK Support about this issue, and they say they are aware of it, and are going to be adding 2 offset values which will be user configurable to combat this problem, and they've told me it will be available in around 2 weeks time, so we shall see. So although it will be a static value, i should be able to get much nearer to 0W import from grid whilst ever there is charge in the battery, but its not at 100%, and its not over its maximum demand (around 1.8kW). To better news, aside from the issues above which should get resolved, the system is essentially running off grid now, and has been since the middle to end of february, pretty much every day without fail, just with the odd bit of import for things like kettle and oven, to cover above the 1.8kW if the Solar isn't generating enough at the time, which is getting an ever smaller occurence. So the graph above is from March, with the Red bits on the top graph being the bits of import. The bit at the top showing 22kWh import, the majority of this was during the early february days after install when solar PV wasn't doing an awful lot. As you can see I'm still exporting ample amounts to the grid also, not that it would make any difference at this stage. Until I get the full years amount, its almost impossible to say how much this will have reduced by. Today I've done a load of washing and then dried it in the heat pump dryer, and following that I ran the oven on its Pyro clean cycle, and come tea time, i'll be fully charged again and ready for the evening (Thai Curry if you were wondering!). This one I'm keeping an eye on, obviously we know that these inverters will never be 100% efficient, but from those figures i've sent 177kWh to the battery, and only been able to get 124kWh back out again. Some of this will be down to the BMS consuming power to keep the battery healthy. So the inverter is 94.0% efficient at charging (100kWh sent to the battery will yield 94kWh of charge in the battery), and 94.5% efficient at discharging (1kWh being discharged from the battery will yield 945Wh). Please correct me if my maths is off! Entirely possible as I've got the plague at the moment! For how much its changed my import amounts, another tricky one which will have to wait for the end of this month, or maybe even next. I didn't get the smart meter installed til the end of March last year, but as a comparison: March 2021 (18th to 31st) - Imported 46.9kWh March 2022 (1st to 31st) - Imported 48.3kWh And this will drop further with the firmware upgrade. Will keep you posted in another couple of months time!

Bury pipe to required depth in trench insulate pipe from bottom of trench to inside house. climaflex insulation is pretty much available everywhere

yup, i was trying to think of that but a long day cladding a dormer side off a roof ladder and shifting scaffold, just went blank.

I've been doing this a long time and had not come across any such ruling (and never had a problem). But some of Yorkshire is high and exposed and perhaps it is simplest to apply a single ruling regardless of location. Southern Water though? My house water (SE) comes in at about -300 (including the meter installed by the water company) and has survived some very vicious winters (to -18C). I found this from J D Pipes. No mention of location or circumstances. Avoid freezing pipes According to 'The Department of the Environment', they recommend that pipes should be buried at least 600mm (two feet) underground. At this depth, the soil acts as a natural insulator and prevents them freezing. A deeper trench will likely be cheaper than insulation, if necessary where you are. For a long run in open ground there are ploughs that make a slit and drop the pipe in one easy operation. But I don't think they reach 600mm.

IIRC, Yorkshire Water ask for anything above 750mm to be insulated. We lagged the pipe as it entered the building and came up beyond that 750mm threshold (basically the length coming through the rest bend), but that's it.

our mains water pipe runs at about 450mm for a short distance and I was asked by Southern Water to insulate the 32mm pipe. I ended up using this https://www.bes.co.uk/shalloduct-water-service-pipe-insulation-835-x-25mm-18496/?gclid=Cj0KCQjw0umSBhDrARIsAH7FCofPjZE97Kx-4mMkVt_XlLonwlnjcnnNwOdcUPzvCi3Hia-Kj6K4GNcaAsfpEALw_wcB inside a blue ducting pipe https://www.bes.co.uk/shalloduct-rigiduct-insulation-pipe-blue-4-x-3m-18515/?gclid=Cj0KCQjw0umSBhDrARIsAH7FCofHqPbJ8g0a1CYXl9oau7cmHLaitE7Z2nweE57W5fsHLg6M2PsHocwaAlcKEALw_wcB which they were happy with.

Frost doesn't really go lower than about 400mm in UK except in exceptional locations. Even then, it would be very short term and the water has a reasonably high temperature unless coming out of a snowy hillside. No, it needs no insulation, and certainly not rockwool which would get wet and horrible.

Our external water pipe is about that depth and not insulated. We live in a relatively cold part of the UK. We don't have any problems with that section of pipe.

Or a nuclear winter

if it freezes at 500mm deep then probably russia dropped a few nukes and we're in an arctic winter.

https://en.wikipedia.org/wiki/Enthalpy_of_vaporization Says 2257 J/g. So yes, think I did get it wrong. So ten times less as you said.

Just having Horlicks for mine, after a hot shower, just hope I don't have horrible dreams, but will wake up at home, so no harm done.

Not happening. Too many friendly critters here. Slow worms, hedgehogs, toads etc.

Yes, why I suggest people stock up.

They say don't open old wounds...

Part of the error will be the heat capacity of your internal wall leaf and other fabric in the house. Assuming aircrete blocks and plaster, your outer walls will weight around 30 tonnes. This would require over 100kWh to raise the temperature by 15C. The concrete floor will weigh a further roughly 40 tonnes requiring around 170kWh to increase the temp by 15C. Including floor coverings, tiles etc you may need 3-400kWh. On top of this there is the drying out energy. I am less sure about the energy needed to evaporate water, but it looks like it is around 1kWh per litre, so this could be a few hundred kWh to dry out the house. (Note I quickly googled this, it is a lot less than the energy required to boil water) I would also be careful of talking about the percentage error in the calculation when you get to quite small numbers. Your house uses around 800kWh more heating than expected. Using gas this would have cost £25 a year until recently, even now it is only £64 of gas. Cost on an ASHP would be similar. Its a pretty small discrepancy which will probably be even smaller after it has dried out and got up to temperature. I'd guess that you are within a few hundred kWh in the second year after the house is dried out and up to temperature.

If you don't want problems with condensation, then I would say yes. But your nogs seem to be the full depth of the joists so when you panel over for the ceiling there's a whole lot of closed-off spaces. Think of what happens to the water vapor in the warm inside air when it gets up to the cold underside of the ply. A vapor barrier may help but they're hard to make perfect when you bore through for LEDs and cabling. Cold roofs generally require a howling draft throughout to be foolproof.

We use PIR sensors in the bathrooms to activate both MVHR boost and the DHW recirculation pump.

Correction sorry, just checked my spreadsheet , these prices do include services

A stool is exactly what it sounds like. Just something to lift the cylinder above the floor. In your case build a platform wide enough to straddle several joists, use 4x2 or 6x2 and some ply on top.

https://coolenergyshop.com/collections/buffer-tanks-cylinders/products/cool-energy-120l-stainless-buffer-tank-ce-b120

There's a difference between inspection for Building Regulations compliance and inspection for the quality of workmanship. Yes, it's a head-slapper, but that's the way in this dysfunctional sector. In building compliance terms, your roof is now signed off ( probably). The BCO was concerned only with compliance. To verify the quality of workmanship , it is normal to appoint a building surveyor. If you do that, please be sure to check that the surveyor is qualified, competent and has a good reputation locally. Get 3 quotes for inspection. It is common to do a visual inspection of a roof with a drone. This forum has many stories of BCOs not doing their jobs thoroughly. It's the norm. To balance that comment, I suspect BCOs are being asked to do more work with less resource. There will be some slapdashery of course.

A man after my own heart. Pulsing the hot return in this scenario would be an epic fail, and using a pipe stat to decide when to pulse would still not yield an acceptable result afaic. Just insulate this run(s) very well and switch on and off via a dusk to dawn sensor for ‘daytime’ use, and then fall back to occupancy switching for nighttime use ( where someone moving at night would trigger a recirc event ). Make sure the hot return pipe is the same size as the delivery pipe, or evacuation times for the delivery ( aka flow ) leg will be hindered by the return pipe size.

Thoughts, not gospel: I think the trickiest thing is the practicality of fitting cables and insulation, as one will get in the way of the other. Cables tight to joists may be the answer. Then fixing the lights through, they will have to push aside the insulation, and it will be a hot little area that might cause the lights to fail. In theory, fit all the insulation you can, with something that will stay in place before you fit the ceiling. No need for any gaps that I can think of. For all that LED lights are low power, it still seems best and simplest to not have a polystyrene layer in contact with them. There will be a cold bridge through every joist though. Or fit a membrane under the joists, then a secondary grid of timbers to create a void that the cables and lights can sit in. There you are, more questions than answers.

I used some and they were OK on 110mm pipes but not essential..

Not sure how pretty you want it. But I used glass wool in the rafters, then sheets of 25mm PIR screwed underneath. Ran electric cable in conduit to strip lights below the PIR all visible.

Thinking about it more, pipe stat is a good shout. If I put a stat on the loop at the furthest distance away, and also use a digital timer to turn off the pump completely at night, and finally use pipe insulation then I think that will do it with the least amount of cycling and be the simplest solution...

There ya go

As I understand things any alterations on the inverter side of the generation meter are alterations to the FIT accreditted system and risk loosing FIT payments. Any alterations to the consumer unit side of the generation meter and thats part of the house electrics which is nowt to do with the FIT accreditted system.

I prefer the Australian & New Zealand versions. Much more interesting projects going on down under IMO.

FIT was disconnected in 2017 and replaced with SEG which does require a smart meter to be paid for export. (It's literally what the S in SEG stands for). But this is irrelevant to the OP as they're not getting an MCS install so won't get paid anyway

I believe that's correct but not done it myself. I suspect the same rules that apply to a new build apply to a conversion or reinstatement. Eg Demolition is reduced rated. Trees and plants only reduced if part of a landscaping plan required as part of an approved planning permission. I would ask someone to quote to "Demolish concrete hard standing, level and prepare ground for turf and lay turf" get them to charge you 5% and reclaim it. You will probably have to pay VAT on any replanting/new trees.

None - you need to put a PRV into the supply to drop it to 4 bar then another at any UVC to get to 3 bar. Running 6 bar anywhere around the house is pointless

@Mr Blobby time to get a company used to dealing with low energy houses. I purposely changed my manifold to the Ivar as it had the lowest temperature mixing valve.

I think location and local weather patterns affect houses more than we realise and very difficult to measure (unless you built a weather station on site fir a year prior to building!). My build is not fully passive and the heating is on fir about 2 or 3 months a year, and then not for long, we have a large south facing conservatory and unless very cold and cloudy it heats the house a lot. I was warned about overheating but with large windows and doors it’s easy to mitigate by opening them.

My life is way too hectic ! - I'm looking for any accountants who could do the reclaim for us. We contacted a local accountant and he wanted about 1K +VAT for it. I seem to remember meeting a team who specialised in this at a build trade show a few years ago that charged about £350+VAT from memory but I've lost their details. Any recommendations very welcome Thanks

I know more about hydraulics than electronics. A bit. Therefore before this discussion gets even more technical here is my input. I would select a suitable wheel that can run at a steady speed to feed your fairy lights, then create the waterflow to suit. Hence a spillway that feeds water from the burn into a full pipe, and then along the line of the burn or bank to the 'power station', gaining clear height. Then an outfall from the pipe onto the wheel which is above a small catchment and thence flow back to the burn. The leaves are kept out by angling the spillway so that leaves flow by but water trickles over, and then a small settlement area where sinkers and floaters are kept away from the pipe, with another weir and/ or gauze divider. Then a gauze over the pipe as a precaution in case of remaining bits. Presumably you would be far enough down the burn that the turbine is above spate level. All the above speaking as the student who caused the weir experiment to overflow onto the PhD student designing a wave energy machine below our mezzanine.

+1 to the above, not a BI,s job to judge workmanship, only compliance. If you want the workmanship checked you will have to find an independent roofer/builder/inspector .