Ed Davies

Also, how many fridges are chucked out because the heat-pump part failed? A few, but not many and most likely because they get noisy rather than outright fail. Mostly people get rid of them because the insulation or seals fail and they get grotty, or they're a bit old and not fitted into a wider kitchen refresh/upgrade.

Just tried with the DC18RC - inserted battery, plugged in, turned on at wall. Started charging immediately. Battery I charged last week so came to full charge pretty quickly. Green light on. Fan still running. Will turn off as it's annoyingly loud, rather than wait for it to go off by itself. That's why I'd forgotten the sequence, I always leave it in another room because of the noise. Wish they did a slower charger which didn't need the fan and probably would look after the batteries better.

If it's the DC18RC charger then the green light on steadily means it's charged. Green light flashing means the charger's on but there's no battery in it. I don't think the fan goes off until a bit after the charge completes but it's been a while since I watched one closely. Normal charge from flat is about 20 minutes I think. Initial charge of a new battery should be shorter than that as they'll be shipped at least partly charged.

Yes, was new to me, too, and didn't respond well to web searches. It's sort of like a French drain where the output of the treatment plant gets mixed with surface water and has a chance to clean naturally before it reaches the watercourse. Specification I submitted to building control attached. First question SEPA asked was “has a percolation test been done?”. For me the test had been on behalf of the vendor and found it didn't - there's solid clay just below the surface (on top of rock only about 500mm down). If the ground percolated they'd have wanted some sort of leach field/soakaway rather than going to a watercourse. Perihelion Rumbling Drain.pdf

I'll have a treatment plant (BioPure 1). Vendor's planning permission in principle specified a rumbling drain. Though the BioPure and the like are supposed to give an output suitable for discharge to a watercourse SEPA like a rumbling drain as a backup. The 50 metre length they ask for seems a bit much, just about OK on my site but must be awkward for many. Asked BC during warrant discussion exactly what they were looking for. “Ask SEPA”. Went to talk to SEPA, very helpful on the paperwork side of things (how to apply for consent to discharge, etc) but as to the practicalities of the rumbling drain: “Ask your BCO”. Made up a drawing/specification of what I thought was reasonable (100mm holy pipe wrapped in 2" clean and geotextile). BC accepted it happily enough.

Doing some other lasering this evening so also did a check of the horizontal calibration I've been meaning to do for a while: https://edavies.me.uk/2018/09/laser-check/ The level is, indeed, level. Or one end of my house has subsided by just the right amount to compensate for it being out ?

Neat. Only really needs to the top shelf, not the bottom one, to swing out like that.

Scottish regs are vastly less detailed. There's a bit more in the technical handbook but the main bit is just: A drainage system outside a dwelling, should be constructed and installed in accordance with the recommendations in BS EN 12056-1: 2000, BS EN 752: 2008 and BS EN 1610: 1998. I suspect you'd need to look at the change history of those to find the source of the change which is then reflected in Part H.

I have a Stanley cross-line laser: discussion here: https://edavies.me.uk/2016/03/laser-level/ It's OK but before buying now I'd try one of the much cheaper ones from Lidl first. Useless in daylight, though as mentioned there using a reflective surface can help a lot. Best to do some marking out jobs at night: https://edavies.me.uk/2018/06/gable-start/ .

So, if the function of the towel rail in a well insulated house is mostly to introduce a trickle of heat into the bathroom, the upstairs and, via the MVHR, the whole house then do we want black ones?

Aren't breakers usually just in the line, not neutral, so an N-E fault in another circuit wouldn't be isolated?

The legal bit: http://www.legislation.gov.uk/uksi/2002/2665/regulation/22/made So, yes, if you've got a normal G83 (or G59) compliant system and you're not going to feed in more than 16 amps per phase then you just have to inform them when the system's commissioned. AIUI the DNOs are happy if the inverter (or the panels) limit the power to no more than 3.68 kW even though this is slightly more than 16 amps if the voltage is below 230 V (a compliant supply can be down to 230 V - 6% = 216.2 V where it would be a tad over 17 amps). What they're worried about is if the line is already close to the upper limit (253 V) and somebody sticking an extra 16 amps takes it over that. If the voltage is sagging and you put a bit more current in you're doing them a favour.

@JSHarris summarises things nicely above but it should also be pointed out that the amount of energy available in the wind varies tremendously with the wind speed. It's that energy which the Betz law says what proportion you can extract. The available energy is proportional to the cube of the wind speed so wind at 6 m/s has 8 times as much energy as at 3 m/s. An increase from 6 to 8 m/s doesn't sound a lot but it more than doubles the amount of energy available. Or, to put it another way, the decrease in wind speeds caused by buildings and so on really stuffs turbines even if they're cleverly designed to deal with the turbulence. Maybe one day somebody will design something which is actually useful for this sort of thing but it's really not worth wasting much time on until they (or, better, somebody else) produces good figures for actual power production. The reason it's cubed is kinetic energy is proportional to the square of the speed and the amount of air you get through the turbine disk is proportional to speed as well.

For completeness it's worth noting that even if something is PD it might still need building regs approval. E.g., I think this would apply to some sizes of garage if they have toilet in them, but I've not taken much interest in the details. Also if there's electricity involved in any quantity that'll have to be signed off, of course.

Indeed. Talked to the local builder/odd-job man for the estate I'm renting off about doing the drains for my build. Hoped he could hire the digger so get that zero-rated but he's not VAT registered himself so that won't work. Smokes like a chimney so took a lot of fag breaks while changing the boiler here but otherwise completely straightforward, experienced and knowledgable and lives only about 2km from my site so would be ideal to help. Pity. Might just pay the VAT anyway.

Not heard of that. Could you say more?

I don't think anybody's recommending that; you should make it clear what parts should be zero rated before accepting the quote. The question is, though, what to do when they charge VAT anyway. I've had three invoices in the last year or so which should have been zero rated or partly so: scaffolding, digger+driver to lift rafters, sarking and membrane on the roof. For all of them I discussed the VAT situation before agreeing to the work. In two of the three I got an invoice with full VAT.

Yes, did wonder about that. Still, maybe the “permitted development” is the conversion from a site hut to a garden shed consisting of taking the kettle out and putting a broken flower pot in the back corner ? Of course, they could say the house isn't complete until the temporary building has been removed. Fortunately, that's a planning issue, not a building control issue, so isn't likely to affect the issuing of a completion certificate, I'd imagine.

Not normally but it depends a bit on which PD right is involved. Some (e.g, in Scotland for a wind turbine) require you to get a Certificate of Lawful Permitted Development (CLPD). You can get a CLPD for any PD if you want to, e.g., if it's close to the edge of what's allowed or if you think a neighbour's likely to be snotty about it. Cost is about £70 (or, at least, it was in Highland and Orkney a couple of years ago).

Indeed. So right up to the moment the completion certificate is signed the shed would be a temporary structure needed for the build. At the exact picosecond the completion certificate is signed it becomes a permanent structure under the PD for the dwellinghouse.

Yes, you're right. Getting confused by previous discussion with @JSHarris where he said it was primary energy which I was pretty sure it wasn't but somehow got it in my head that it was therefore final energy. Well, it is final final energy, sort of ?

Yes. Would add though: The key thing these have over, say, an Arduino is the built-in ability to do Wi-Fi. In fact, they're more like Wi-Fi chips that happen to have some spare processing capacity to do other things. The more modern replacement is the ESP32 which has a few nice but not completely compelling advantages. But if you're starting from scratch you might as well use the ESP32.

My original logging was purely to text files. I tried both MySQL and MongoDB. Gave up on MySQL pretty quickly as it was such a clunky old-fashioned bit of nonsense - e.g., text not being Unicode by default, hassles with passwords and stuff. MongoDB was OK but depending on the indexing the query performance was very poor for either lots of recent data or sparse long-term data. Sqlite has been working fine for me on an SD card with, currently, 1.7 GB of data since 2016-11. If, as a result, the SD card dies every two years or so that's probably acceptable. Still, I'm thinking of going back to text file logging though with a slightly different architecture from my previous version mainly so I can back up the database to my laptop more automatically and continuously. Yes, MySQL would probably allow that but with a lot of faff, no doubt.

There are two things in Passivehaus like that but neither are that: 1) 10 W/m² as the peak heating load in the design-worst case conditions. So you're 49.6% over that if -10 is your design worst case. 2) 15 kWh/m²/year as the total energy use for space heating. Both are, I'm fairly sure but not certain, final energy use. You get to choose, you can meet either of these criteria, you don't have to meet both. I really hope there's a spurious “/m²” in there!

I think it's just that the relevant permitted development rights apply to a “dwellinghouse”. (Class E in http://www.legislation.gov.uk/uksi/2015/596/schedule/2/made). The Interpretation section (http://www.legislation.gov.uk/uksi/2015/596/article/2/made) isn't overly helpful here but presumably a house isn't a “dwellinghouse” until you can dwell in it, which you shouldn't until you've got a completion certificate. Had this discussion with a planning officer on Orkney saying I might or might not want a wind turbine but it'd be PD anyway. Her reply: not until you're complete, better to put it in the application from the start.