TerryE

I had IOLs ten years ago as well, but I still can't focus at 15cm unaided. Even at 0.1" pitch, these made doing fine solder work just so much easier. And to NickfW's point there is 4 different strengths plus compounds.

But have you got some of these. Absolutely essential for old farts when soldering!

Nick, when you want move from breadboarding to something more permanent, then you will either need the prototyping hat or mount the Wemos as a daughter board on a through-hole board, and UPS hat. Just shout if you want more details.

Don't know about Windows. I suppose that someone might find a way of screwing you, but the entire stack is FLOSS. I just plug my Wemos into my RPis and Ubuntu laptops and they work.

@MikeSharp01, Mike, If you are comfortable in C and the Arduino IDE, then the ESP is one of the targets. I've used Python, but not the embedded uPython on the ESP8266. The Lua RTS that I work on is more as Javascript is to Java then Lua is to Fortran. It's another late binding language like Python, Javascript and Perl, though the RTL is event driven -- more like node.js. The nice thine about the Wemos is like the Arduino, you just plug the module into a USB port and away you go. I've a a couple doing all of the I/O on my heating system.

Nick, why not with one of the developers of the Lua firmware for the chipset -- me? For a start don't use the bare ESP-02 or even the the ESP-12E modules as you will need UART, and 5V to 3.3V drop-down. Use the Wemos D1 mini. This can be powered and programmed over USB serial port. Wemos do a range of shields as well. The price is about £6 from the UK or £2 from China -- if you can bare the 3 week delay. Give me a ring if you want to chat about options. //Terry Counting the flashes on the meter is easy, even with Lua -- though if you can't get power to the box (yea, yea, I know, but ours is outside) then an always-on Wemos burns through battery. You need a low power I2C counter timer; you can then put your ESP8266 into deep sleep and wake up every 30 mins or so to send the reading to your RPi or whatever; this will run for months on a LiPO. (And Wemos do a cheap charging shield for the D1 mini as well.)

@tilpol, if you are doing a newbuild and can get your wall U values under 0.15, windows & doors under 1.0 and avoid the "acres of glass" that so many architects love, with a decent insulated slab, good airtightness and MVHR then you should get your space heating needs down under 2 kW even for typical Jan / Feb. The problem with a wood fire is that you will have a great deal of difficulty keeping the power output under 6 kW if you want it to run efficiently, and the burning efficiency of stacked wood isn't good; anything less than 2 years drying, terrible. A bit of a dilemma, really. In principle the RMH approach solves this by burning at a high output for shortish period, once every few days and dumping the heat into a thermal store (typically cob) which you can then draw down as needed into the house fabric through UFH or whatever. A quick search gave this interesting thread. As this thread points out there are a lot of issues such as no commercially available appliances with HETAS certification. A difficult one.

That podcast is well worth listening to, BTW.

Nick, Costing the Earth did a really good podcast on Eigg's energy solution, and one of the major goals was to provide at residents with a guaranteed supply so long as they stuck to the <5 kW cap, and one of the aims was to get rid of all the noise polluting Diesel generators. All houses have a 20A trip on the supply. Basically its such a PITA losing your supply that most islanders just learn to shape their demand to avoid getting tripped. I can't see anyone needing 120 kWh a day, so the issue isn't the overall capacity but how you proactively manage your demand to avoid the 5kW trip.

No you can't. The phase change cells are only heated by electricity and have internal plate heat exchangers to exchange heat with the potable water flowing through the device. so if the PCM is between 60-65 °C then the input water at 10°C, is heated to a similar temperature but this is then mixed down using an internal TMV to the preset temperature between 40-55°C, say. We have two SunAmp in parallel heated solely by E7 low tariff supply. We preheat our direct mains for HW though a PHE exchanging heat from the slab, which raises the temp at the riser from ~8°C to 20°C. This is then heated to ~56°C by the SunAmps and then blended down with more cold at 20°C to 46°C in our Manifold TRV. Hence the SunAmps raise our DHW by roughly 26°C. Jeremy has a single SunAmp which he feeds via a PHE from a buffer tank which is preheated to ~35°C using his ASHP. The SunAmp again raises this to ~56°C and this is then blended down to his set point probably around the same 46°C but in his case this is with borehole water at ~10°C. Do the maths to work out the overall heat delta per litre delivered, but this is a lot better than mine but maybe 2× rather than 2.5 × because of his mix down using 10°C water. But that's why he can get away with one SunAmp whilst I need 2. But the take-home message is that using a preheat buffer tank heated by the ASHP can effectively double the SunAmp capacity but you still need to heat them with electricity.

I've got twin SunAmps and I am delighted with them, but they definitely have a sweet spot -- that is where you need a high thermal capacity density with low heat losses. If you are looking at onsite wind, some form of solid fuel heater such a an RMH, or infill kW from your 5kW allowance (120 kWh is a lot of energy to use) then I would have though some some of high capacity buffer (either water or solid) at ~30°C also acting as a DHW preheat might prove more effective or at least cost-effective.

Yup this system might be 30 years old and never routinely maintained or it might be a modern design. Different probable failure modes.

Another typical problem is that any the thermostatic values are sticking. Also have you got a sludge filter in your system. If so when did you last clean it out? if the back boiler is new enough to have one. Do you know the make, model and approximate age of the fire and backboiler? Do you know what your topology is? If you have multiple loops in parallel, then you might have balance or backflow issues, especially if you have non return valves missing in some of the loops. Another potential issues is airlocks in any swan-necks on feeds etc., or in the boiler itself. If you have multiple loops then an airlock in the boiler path might just result in the pump circulating the water down one loop and backwards down another without circulating through the boiler at all. A diagram might help.

As a PS, I see that your total wall profile is ~300mm. If you want an energy efficient TF then you are really looking at a total of 400mm minimum and probably 50 -100 more than that.

The 5kW limit is quite workable for a new build if you are willing either to do manual scheduling or some from of home automation scheduling of high load devices. Most kettles peak at around 3kW, so a kettle + a cold fill washing machine at the same time will be enough to "punish" you by tripping the 5kW breaker. So some things are obvious: hot+cold fill for your washing machine, dishwasher, etc. LPG for cooking. But the main challenge is how to get the bulk kWh for your space and DHW heating. Bulk LPG is a no-no, I guess. And there is almost no coppice supply for renewal timber stove heating. Clearly as others have said, a near zero energy build will make a big difference on the demand side, but you will still need to have 10s kW input per day for space and water heating. And you will need an economic source for this, especially given the 3 km rough track access. There are ~50 other households on the island and these must include some good working examples. We have an MBC warm slab (search the forum; there are lots of debates about the advantages of this technique), but this includes ~10tonne of concrete inside the thermal envelope of the house which acts as a thermal store. Have you explored some like a rocket mass heater (RMH) option? RMH systems often use cob rather than concrete as the thermal mass, and cob would be a more practical material in your case so long you are not relying on structural characteristics. I have seen example (but I can't remember where, sorry) where someone effectively put a keel in their floor slab (surrounded by EPS) and heated this with an RMH to around 30°C. By having one UFH "zone" running through the keel, this heat could be redistributed on demand to the rest of the slab, allowing the short burn RMH to provide a day-round steady space heating supply as well as working as a DHW pre-heat. Sorry, as this is a really a Boffin's Corner topic and not something to consider lightly, but what I am saying is that there are energy-efficient options that you could consider. @JSHarris, @SteamyTea et al, perhaps if you want to discuss this point, then we should move this discussion to the BC sub-forum as @tilpol has enough to consider at the moment.

Our private BCO defined three inspection points: When the MBC warm-slab formwork was complete before the concrete pour When the stone skin was up to 1st floor level to inspect the TF, foulwater plumbing, stonework and cavities. Completion. We've swapped emails and pics on a few design points and provided the list of docs that he wanted. Just as built SAP docs and completion inspection to go.

Now you're onto discharge of conditions! But still, congrats

The major flaw with the lot20 approach is confusing a sub-component with a system. My house uses a 3kW heating coil to heat the house. It takes 3kW electricity and turns it into heat. Yet my house as a whole is well within the top 1% of UK housing stock, in terms of its overall efficiency.

How about this:

But it does have to be done properly otherwise the pour will be a disaster. This isn't just a case of putting out some EPS Leggo bricks. Our SE had a Geo survey to validated the depth of hardcore base, drainage, etc. needed and this varies depending on the subsoil type. As I have said on other posts, the guys were extremely particular about compacting this in 50mm layers to a survey level, and then adding a 50mm sharp sand layer. They rejected the first batch of sharp sand because it had too many fines in it. When I asked the gang-leader why they we so particular, his comment was that the greatest risk in this type of pour was differential subsidence across the slab. We've had one member here hit badly with this issue when his slab slumped by 25mm in one area because of poor compaction. Likewise the rebar design has to be properly engineered for the design loads and then properly installed and tied in. And the pour need to be properly compacted. We've had another member whose installer didn't compact the slab so it failed inspection and had to be broken up, removed and reinstalled. So yes, I agree with your basic thesis that this type of slab, when properly installed takes less work than a conventional beam and block foundation + insulation, USH and top screed, and both cheaper overall and better performing, but you need a skilled team. But these skill need acquired, and you need to proper quality checks when doing the job, otherwise things can go badly wrong. I just think that a typical jobbing builder won't have these skills or quality check in place.

We had 24V CAME arms on our last gates, though the power to the control box was 240V. There is a max pressure that the gate can apply for safety reasons, and the arms themselves are highly geared, so the max power is only 100W or so, so the wiring from the controller to the arms was single sheathed 5A multicore, IIRC, but this was only between the controller and the gate arms. This was run in a 20mm flexible PVC conduit.

++ to all that the other MBC customers' comments. We are another one. Our slab was different because it was also supporting a stone skin. Hilliard, the SE that MBC uses specialises in these and knows his stuff. The SE calcs that he provided kept our BCO and warranty provider happy. Another thing to note is that MBC use installation crews that spend their lives putting in this type of slab. In our case, I found that they really knew their stuff and were amazingly particular and professional in the details of construction. I was extremely impresses with them and their work -- a league away from the usual building gangs. MBC is just one case, but the main point to take home is that designing and implementing these slabs have a lot of subtleties that the specialist companies and crews have refined over the years. Your house is going to be standing on these foundations, so you can't afford to get the design or the implementation wrong. It's just not worth the risk. My advice: use a specialist company with lot of installation experience, a decent track record with consistently good references from their customers..

About 15 years ago not long after we put in WifI, I decided that I needed to add a second WiFi at the other end of the house because we were getting zero coverage there. Trying to cable up from where our ADSL router was a total PITA so I drilled a hole out through the wall and took the Cat 5 (as it was then) out around the house and back in another hole to a face plate. We had pea shingle over fabric matting and I just pulled back the matting, lied the cable and replaced the matting and pea shingle. 15 years later and my new neighbour is still using it!!. My point is if there isn't a real requirement to do otherwise then why not keep it simple? Duct rated Cat cable needs this rating as a protection because of the risk of having X cables in a duct. In this case surely a 25mm pvc flexible conduit running just under your final paving at the minimum separation would be fine, IMO.

We split the plot of our previous property and built our new build on the bottom half, so as it happens we were living next door. But my point was that we didn't raise a loan on the new build, we remortgaged our existing property, and this gave us enough cash to do the build, though it was a bit tight at the end. There was nothing underhand here. We were upfront with our BSoc (Monmouthshire) and even got a no capital-repayment loan at an extremely competitive rate (under 1½% for first two years) because our stated repayment strategy was to pay off the loan from the proceeds of the sale of the farmhouse. I don't know what your circumstances are but if the asset value of your current property will cover a combined value of any existing loan and the cost of the new build then you might be able to raise the capital solely on your existing house. If you can do this, then the rate will be better than you will typically find for a new-build loan, as the lender does not bear any risk associated with the build.

We dumped a load a couple of weeks ago in our pre move-in clear out. It's really not worth while attempting a DIY because you will still need to convince your BInsp that your home brew attempt achieves the required fire protection. We bought our online from this site: Insulation Express.co.uk: Rockwool Fire Barrier. I am surprised that you are using your local BM. We found that you can typically get stuff cheaper and faster on the internet.