Bramco

Hi, now I understand the comment! ? However, I should have added I guess that the UFH is built into an insulated slab and the house is almost PassivHaus levels of insulation, so we'd be following the advice from other members with similar construction to heat the slab once or twice a day and not use thermostats for every room. So there shouldn't be an issue of the ASHP turning on and off. Simon

Not sure I understand that - the ASHP simply circulates heated water through the coil in the buffer tank - so surely it can deal with a v small tank which it would heat quickly, or a v large tank which it would heat slowly? I reckon there will be roughly 140l of water in the UFH pipes. Simon

Hi, We'll be following the advice to fit a buffer store between the ASHP and the UFH in our new build and it occurred to me that the size of the store required might be dependant on the volume of water in the UFH pipes. We have 12 loops, each about 100m in length. Would 50l be enough, too big, or just right? Simon PS apologies if this has been asked before

Here it is -> From what I understand it's a lot easier than it used to be - ASHPs have been improving over the last few years as manufacturers add new features and the rest have to catch up. So they are all quite similar in terms of features (someone will no doubt be along in a while and say the opposite!). From reading the forum though some are apparently easier to program than others - although once programmed, you probably won't have to use the interface again in years, so maybe even that isn't really an issue. Simon

The digger driver doing our culvert snapped the BT line to next door - Openreach have a 24 hour service to fix things like this. I bought him a fridge pack of Magners cider and he seemed OK.... Our roofs and the cladding on the 2 storey section are black corrugated steel - one contractor has mentioned up to 16 weeks lead time..... We used an M+E consultant to do heat loss calcs - there is a spreadsheet on the forum which you can download and dial in your U values for roofs, walls and floors etc. - I had used this earlier and it confirmed what the consultant's report said. Gas would be an arm and a leg as there isn't any down our lane. Even so, I think we'd be having an ASHP installed. We're having PV installed and when our car packs in, will replace it with an EV which by that time, we should be able to use as a house battery - so should be relatively self sufficient. There's lots on ASHPs and RHI etc. on the forum. If you can't find the heat loss spreadsheet, let me know and I'll find a pointer to it. I'll PM you about where we are in case you want to cycle or drive over to see our build. Simon

Hi Kevin, We're very local to you. Our timber frame is going up at the moment - the first lorry load arrived on Tuesday. Hope you had an easier ride from Rushcliffe than we did with your planning. If only they'd done their job properly, we'd have been in the new house before Covid and missed all the current shenanigans around shortages of materials and labour and the cost increases... Are you doing the rest of the build yourselves, or have you contracted a builder? Simon

Couldn't agree more - the thought of having to program everything from scratch isn't just daunting, it would be crackers... And thanks for the clarification on Loxone wiring. Simon

Hi Dan, I didn't want to say it's complex. My understanding is that it requires special cabling - so adding to the cost. The industrial shields (link above) is Pi based - but then you'd need to be installing HA or something similar and then of course you have to manage that over time. And there are alternatives to Shelly, like Moes and Sonoff. I've used quite a bit of Sonoff kit and it seems to work fine although if you don't want things to go through their service, you need to reflash with ESPHome, Tasmota or similar. There's an interesting Kickstarter just started from Sonoff which I saw today -> https://bit.ly/3BDX7eM. It's a wifi panel with a lot of functionality built in. Sonoff NSPanel Smart Scene Wall Switch. I've backed it as they looks as if it might be something I could use. About £50 with shipping.

I've also found -> https://www.industrialshields.com/ As far as I can tell systems like Loxone and Control4 etc. are pretty expensive but then they do cover all of the functionality a person might need, including audio and video etc. and they are very flexible. PLCs are much cheaper for the hardware, a 4 input, 4 output LOGO PLC is just over £100. So if all you want is the ability to manage blinds, rooflights etc then they would be much more cost effective. The tools for programming PLCs are much better these days. We want a relatively simple system without any special wiring, like the Loxone wiring, so I'm leaning towards a PLC based system. Simon

Thanks @BMcN Thinking things through, I guess it comes down to the price you'd need to pay for a PLC with enough inputs from the switches against any other system. I've got 20 inputs from switches for the rooflights (up, down for all, some switched together etc.) and then the outputs, in our case 12 (6 rooflights, up and down). Easy enough to program but does the cost start to build up. Simon

Not actually programmed any in anger but understand the principles and have programmed lots of other things. I may be able to make it simpler still with just some relays connected between the blind and rooflight controllers so that we can mainly do it with rocker switches. Need to really sit down and work out how we want things to work and what we might want to control automatically. Thanks for the link to plcs.net Simon

Just looking for alternatives to Loxone etc. for simple automation of blinds, rooflights, heating etc. and realised that PLCs may offer an easy and relatively cheap solution. For example the Siemens LOGO PLCs have analog and digital I/O, ethernet and a web interface. Simon

You can spend a lot of spondulies on this stuff and then have SWMBO ask, with a quizzical look if it was all worth it. And in most cases the more you've spent the harder that justification goes. Being able to turn on the heating when you are an hour or so away from home is one good and justifiable use case - unless you live in a well insulated almost passivHaus house in which case it's nonsense. In our current house it's a good thing to have, in the new build not so good. In an old house it's easy and relatively cheap to achieve with for example a Honeywell Evohome system - there are other suppliers. When you are away, having lights come on as if you are home is also useful. Again easy to achieve with some plug in wifi sockets and table or standard lamps - we have some sonos jobbies and use a 'scene' in Google home to turn them on at dusk and off at 10:30. Again simple and easy and cheap to do. In the new build though...... Actually, we're really struggling to find good solutions where we use normal wiring and can have both at the wall switch control as well as some programmed stuff. And we also will have to manage rooflights and outdoor blinds.... The main thing is it has to be usable from a simple wall panel or it gets too faffy. Hmmm need to turn the angle of the blinds a bit - 'shit, where's my phone...' 'can someone call me, I can't find my phone?' 5 minutes later and the cloud has moved on... Simon

Not sure why you would want to withdraw the application because of the construction method. Unless an aspect of the design would be prohibitively expensive in your chosen method. As your architect had advised timber frame, they must have considered the design as easily done in TF. I believe that you get your fees back if you withdraw an application, you also get a 'free' resubmit if if fails first time round. There's always a further option which is to put in a 'non material amendment' once planning is approved - although this can only be on non material aspects, e.g. position and size of windows etc. I think there's even the option to put in for material changes.

indeed - ours are filled with old bricks, set so they are interlaced as much as possible and therefore very stable - and a lot cheaper than filling the backs of the gambions (as they are known in our house) with expansive stone. Mind you, you need a source of cheap old bricks.... Simon

Yes, it will flash twice as fast.

Superficially they do behave differently but in terms of units registered for charging purposes they all seem to work the same - I think this must be in a statute somewhere but as I said I can't find this. Our previous meter used to go solid red when it had detected reverse energy - which happens when the immersion has heated up the tank to it's target temperature, i.e. it can't take any more surplus energy. The smart meter doesn't do this. The old meter flashed 1000 times per kWh. the smart meter 2000 times. But these are just the way the meters display info for us users - the key diverters all working with different meters is the regulatory charging unit of 1wH which allows diverters to work by avoiding repeatedly going over the next unit. Simon

No, they don't work like that. The isolation from the grid occurs when there if there is a power cut - the inverter handles that. There is an isolation switch in the circuit to the immersion heater (as normal), so we can isolate it if needs be. To turn off the diverter, we can simply unplug it and there's another isolation point in the feed to the diverter. But these are all manual. No. The immersion in normal operation is only connected to the diverter. So it sops up as much energy as the diverter can divert, even very small amounts. Essentially these things work by continuously monitoring the mains flow (samples at about 50 times per mains cycle, so 2500/s). If reverse flow is detected, then the diverter starts diverting, even if it is a small amount. The 'bucket' algorithm, make sure that the 1wH charging unit threshold of the meter isn't transgressed, so the meter doesn't register a unit used while the diverter is diverting. This is important whenever the amount of energy that can be diverted is lower than the rating of the immersion. If you didn't have the bucket algorithm, you would be importing the difference to make up the full 3kW of the immersion rating. Simon

He may have introduced the forum to the concept but I think it was described earlier on the openenergymonitor website where there are a couple of implementations of this that you can download if you build your own device. Obviously the OEM site may have half-inched the term from somewhere else.... Simon

Mine works fine. I was also concerned when we had the smart meter installed - I built a diverter as described on the openenergymonitor site. My initial concern was that the smart meter states on the outside that the led flashes at a rate of 2000 impulses per kWh which is twice as fast as a normal meter. However, this is just the flashing led, not what is being reported as usage. Usage is still measured in 1Wh chunks or 3600 joules. Although I can't find a spec anywhere, it seems that this is the standard charging unit for electricity in the UK - and it would make sense that all meters report the same charging info, regardless of what they might show on displays. There was a long discussion of this on the openenergymonitor forum a few months ago. You may ask how I'm so sure the smart meter isn't working to a more accurate standard since I can't find a spec for the charging units. Well, once the smart meter was installed, I waited until we had a really sunny day where all of our excess PV would be diverted to the immersion heater. On the Octopus web site you can see the usage per hour and sure enough for several hours when we didn't use any big appliances we were charged 0.0p and I could see from my monitoring of the heat bank that it was being heated as normal. So I'm not absolutely certain but I do know that the diverter is working as designed and it's not drawing any power from the grid when it's working full tilt. I should add, we only have 1.75kWp on the roof, so all of the maximum generation can be diverted to the 3kW immersion heater. Simon

It is a great feeling, having investment coming out of the ground rather than the earth being a massive money pit! I'd show our insulated slab which has just bee finished but I can't seem to get a picture in here. Will try later. Simon

When we finally get our new build finished, it will probably be an EV to soak up our PV and any cheap night time electricity. Apparently there'll be a shortage of wine at Xmas, so I'm buying in just in case (wonder how much will be left). But with the fire the French caused on the cable that we use to import lekky from France, I'm also going to be buying wood (still have an open hearth - maybe I should have specced one for the new house - mind, it's timber frame, so we'll be OK......) Simon

That's gotta be the wild west to get any generation at 7:30pm.... Isles of Scilly sunset time today is 19:38 - only 8 minutes after here in delightful Notts... Are you sailing across the pond? ? Simon

You'd need a big torch to get decent generation at 7:30 at night!! Simon

Triple glazed, MVHR and massive open spaces - it's not like steel framed single glazed windows in a 50's council house with the washing on a clothes horse in front of the fire....