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Transmission losses and power station efficiency etc are all accounted for on the published figures for carbon intensity of fuels, which are updated annually. The carbon footprint from UK domestic electricity per kWh is about 10% less than that of domestic gas, furthermore it's falling as we move to renewables. That means that a heat pump with a cop of 3 causes less than one third the carbon emissions (actually it's a bit better still than that because most has boilers are set up by the heating industry in a way that makes them less than 100% efficient). This stuff is well established and the carbon case for heat pumps irrefutable.

Your MVHR will do that on its own. We only use the extractor on rare occasions now (smelly stuff and only on low) MVHR does a good if it on it own. A house with MVHR isn't the same as a normal house with intermittent fans. House feels and act differently. Anything else is a design thing down to personal preference.

I can currently get building insurance, for £50 a month but thats only if there is no ongoing subsidence! I want to get structual engineer involved but its the cost I may lose if I pull out of the transaction! The original cause was root induced clay shrinkage from the shrubs in the front garden!https://imgur.com/a/6TtnVgd these are all the photos I have of the garage, the cracks do not go to the floor and the different brickwork doesnt go to the slab either, which make me think it was a repair job in the past!

Bolts assume is fence posts? What has fence posts got to with concrete Lego blocks, they are about 2m³ each. Just use postcrete, get it by the bag from any DIY outlet or builders merchants. Not sure why you need an oil drum of concrete to secure a fence post. Maybe you need to expand on what your doing to get better answers, sorry we can only go on what you write down.

For UFH you should be bonding the flooring to the screed. An underlay acts as insulation

Hi, Screed is down and dying out. I have wet UFH in 50mm of anhydrate screed. I plan to use engineered timber flooring. I’ve had the screed sanded to address laitence etc. The question I have is whether to lay underlay, or bond directly to the screed. I have been advised that underlay will impair the efficiency of the UFH? I’d appreciate your advice please? Thx

Hi @kyran It looks like the wall on the right hand side of the crack is dropping going away from the left hand side. Yes the RSJ on the pad stone is pushing down, but the foundations holding up the RSJ wall appear not to be capable of holding up the load. Also it looks like the crack is where 2 different walls have met, presumably the foundations below each part of the wall are different. You may also want to clarify how much this house insurance would cost. Also what caused the previous subsidence. Was it a drain or roots or quality of the foundations or the soil. You can pay a high insurance premium for a building that has had subsidence for 20 years!

The 250% figure is for kwh delivered at your house (including transmission losses) assuming a 100% efficency boiler. Ie volume of gas burned in a ccgt plant is 2.5x the volume of gas burned in a gas boiler to deliver 1kwh of heat in your living room. So, as long as your heatpump can achive a Cop of 2.5 or better you will burn less gas in the power plant than you would in your boiler. 2.5 is pretty achievable in all but the most ham fisted installation. If we snapped our fingers and swapped every domestic gas heating system with a heatpump and created enough ccgt plants to power them, our national gas demand would fall.

So nothing special. And it will be an oil drum filled with concrete? You could add bigger stones, half bricks and it would be fine.

This illustrates my point very well. You need the range to go there and back on one charge because you're anxious about the trouble of trying to charge away from home. Which isn't a.worry with ice cars. Imagine if petrol stations were really rare and had very slow pumps, 30mins to fill Your 200mile can would be pretty stressful. Everyone would want huge tanks, which would take even longer to fill etc. Some of the new generation of Chinese LFP batteries can charge at 10C, ie they can fill in 6 minutes (assuming you have a powerful enough charger). In practice it's a hit linger because of charge curves but people don't usually fill 0-100, it's 20-90 or something. For a 100kwh battery that's a 1MW charger! But for a 30 kwh battery ,which could do 120 miles, you only need 300kw, which are not impractical. My longest daily trip is London and back 150mi each way. I do it a few times a year. Currently easy on one tank. If I had an electric 150m range would be doable *if* I could guarentee an easy fill up at the other end. Otherwise I need 300 miles (plus reserve)

We run a COP of about 3 atm (heavy users of hot water), but with off peak leccy at 7.5p being 90% of our ASHP energy usage, we're making significant savings vs gas. We also then run the dish washer etc during that off peak rate. Then we don't pay a gas standing charge which is the icing on the cake. With this setup, even a COP of 2, we would work out cheaper then gas I recon.

IIRC the upstand is on top of the underlay.

Who did you use? I just got a quote from https://www.prefabricatedhomesuk.co.uk/ and its so expensive.

Hiya We have started designing our kitchen and have faultered at the design of the hob extractor. We have a MVHR system, but want a supplimentary hob extractor. The kitchen has a vaulted ceiling which means a "traditional" design over-hob extractor can't butt up against the ceiling for a clean design. We also aren't planning to have any wall cupboards so an extractor built into an over-hob cupboard wouldn't work either. We have looked at venting hobs but are worried that they won't have enough umphh to control the steam and are massively overpriced. Any help would be appreciated particularly with over-hob extractors which look nice "free-standing" on a wall with no cabinets or vented hobs. Thanks

If 4000k works from dawn to dusk for you then yes that’s a cheaper alternative. I’m mostly a night owl too, but I think there is value in having a way to subtly wind down near bedtime and the older I get the more I realise how lighting impacts that. absolutely. Mismatched temperature lighting is awful. Bulbs is the difficult aspect. LED strips are cheap and easy to do as CCT but I’ve still not settled on the best way to do temp changing bulbs as I’d rather not have smart bulbs but smart controllers, dumb bulbs. After the last conversation we had on this topic here I’ve started considering buying non cct bulbs and gutting them to replace the LEDs with CCT ones and controlling them with a custom controller as mad as that sounds because I’ve not seen products that do what I want.

Im currently buying a property that's has had previous subsidence, my level 3 survey has picked up cracks in garage which he says is likely ongoing subsidence. But im not so sure, as I think its more to do with the rsj... any help?

If fiddling with the cost of electricity/gas is part of this, the progressive approach would be to reduce standing charges, which have become inflated in recent years.

TL;DR Got ours installed last month. Obsessed with the details now. Energy Savings Trust PV calculator is excellent although we went for double the size. I think you are overestimating the number of panels that will fit. They are big and don't come in that many different sizes or shapes. Similarly crap solar PV forecast in my location, but it cut our usage by 50% in Oct-Nov. Ours is the SE roof only, 45 sq m in 22 panels giving 9.8kwh peak, house footprint is 75 sq m, generated 6.5kwh last month with a large battery. Info dump to follow. Scroll to pics. Estimated solar PV needs We started off with the Energy Savings Trust PV calculator, super helpful but it wouldn't do calculations for our size of system and limited our annual electric use to 6,000kwh when it is double that (yours will be on your bill). Solar PV depends on location - not just roof direction - west coast UK being the worst area (dark clouds and thick clouds)- put it in a calculator to find out, but it also depends far more on time of year. It can vary a lot between days - batteries will smooth this out - but what you will notice more is exporting excess to the grid most days in summer, and rarely being self-sufficient in winter (depending on your calcs). Several apps will do a daily solar PV estimate if you enter your longitude and latitude, expected system size, and the angle ("azimuth") which is usually degrees from South. Typical roof pitch is 35 degrees. PV Caculator and SolXpress are free ones. You can monitor the predication charts this winter, compared to average daily usage (from your bill). Heat pump cylinder Some of solar PV compatible and some aren't. I have no idea what this means since that's next year's job! Batteries are big They can go outside (under a shade canopy), in garages and I think probably in lofts. Might fit in a garage loft if it has a sloped ceiling. It CANNOT be fully boxed in because ventilation is needed but this can be at the top, sides, and underneath if wall hung. If you put it outside the garage you can hide it with planting on trellis or similar. We can't get them outdoors here due to limited space. Our house layout is extremely complicated with no garage, and internal thick stone walls. We have a 13.5kwh Givenergy All in One battery unit and it fits in a typical "alcove" - its at the side of our disused chimney breast where you might fit a bookcase and takes up almost the full depth and width of the alcove. It is about 1.2m high x 0.65 x 0.65 (I think), above it are 2 small string inverters (Solis ones about 0.30-0.35m deep) and 3 isolation switches plus the cabling between them so basically nearly up to ceiling (which is quite low) and about 0.20m off floor. It actually works well with something similarly sized in the other alcove. It is similar to a 250L heat pump cylinder but boxier, and has string inverters above it (they are not much bigger than A4 paper but shouldn't be right next to each other). You can probably get much smaller batteries but ours is a modular system we can easily add to. It does hum, the smaller string inverters are much quieter. It is a large capacity battery given the size of our panels, although your home is much bigger I think (assuming you have 2 floors) so you might want similar battery size. It is in the office/study and I plan to cover the front of it with (removable, painted) ply sheet with top and underneath gaps for ventilation - luckily we have a MVHR supply valve right above it that gives continuous ventilation moving heat away from it. I wouldn't be able to tolerate working with the hum but it is fine for my other half. LAN cables needed for us (dodgy wifi) go up to ceiling and under upstairs hallway down to router. I think I remember that the battery should be near the string inverters and panels, ours is directly below the middle of the panels. Further away works but you can lose some power I think. You can fit to outside of house under opaque canopy, or in an unheated porch (it will warm the porch a little). They should have shutdown safety features, fire risk didn't come up when were seeing installers but they can get hot especially boxed in. Ours briefly got to 31C in October indoors which is fine (we are in a stone house that doesn't overheat). I wouldn't put one in direct sunlight though. And don't put it in the lounge or a bedroom lol because of the bright LEDs and hum. Wide hallway would be fine, under the stairs if not enclosed by a cupboard. Kitchen or utility would be ok but I would raise it a bit off the floor in case of flood from washing machine. You don't have to have batteries but if you do then you will be able to get the bonus export prices during high demand, and it will pay for itself quicker, and in winter yoy can charge batteries from the grid at night for us in peak hours on gloomy days eg 5-7pm when it is dark. Calculations example 43sq m of panels (22 panels), all SE facing, 9.79kwh peak, 13.5kwh storage, West of UK (poorer solar irridiance), no shade, typical usage 13kwh/day. Installed last month (mid Oct), first electric bill since showed 50% less electricity usage. Our typical electric bill is £120-150/month, in summer we except export amount may cover the £13 standing charge and zero usage. 13kwh/month going up to 15kwh in spring, autumn and winter once we get a ASHP and EV. For us at the moment (mid Nov which is the 3rd worst solar month, we are in the west coast, by hills), today Sun is forecast 18.6kwh, Mon 21.5kwh, Tue 3.8kwh but last 2 days were less (storm and power cuts). Our usage is 13kwh/day (no heat pump yet but an electric immersion heater runs the hot water, induction hobs and electric oven). Our batteries are 13.5kwh so these few sunny days this week will be self-sufficient and charge our pretty flat batteries enough for an extra day (75 sq m footprint, 9.8kwh system only on the SE roof so not ideal setup. BTW we have A LOT of battery given the number of panels, and the fact we only use 13kwh/day. Exactly 1 month after getting solar PV our electric bill was halved (and that's for October!). We haven't yet got income for exporting and the standing charge came to £15. We are expecting close to 100% electric met by solar in summer because there won't be a heat pump on. It will be a 8kwh heat pump with SCOP approx 4.2 so should run at about 2kwh when it's on, given it is an old house it will need more heating than many. We don't know how not having an immersion heater will reduce the bills. We can decide after a few years on whether we should do the NW roof, since adding to the system is cheaper than the initial install and we won't increase battery capacity. It is a modular system so adding or upgrading the string inverter plus the new panels is all that is needed, but pv panels may have improved efficiency by then. We went for extra batteries to smooth out the times when there are several darker days in a row particularly in spring and autumn. Payback time In general UK solar PV payback time should be 7-10 years usually (it is better if you have some batteries), occasionally up to 15 years payback but it can be up to 20 years for direct North facing. (This is assuming that you are getting hot water from electrics.) For us having off-grid generation and battery use during power cuts was about 2.5 years extra payback time. Electricity standing charge currently approx £0.50/day (£15/month) but this can be offset by money from exporting. MCS certified installers will do very helpful calculations for you including estimated kwh, price savings and payback time. Some energy companies will give you a much higher export rate if you get them to do the install as well. Export rates (SEG tarrif) can be anywhere from 1p/kwh to 21p/kwh and you need a smart meter (with a working half-hourly signal) for this Power cuts If you want to generate or use your solar for the ASHP during powercuts you need extras eg a gateway (often there is a single plug EPS that can work from batteries but solar PV generation disconnects for safety during power cuts. We had 3 brief power cuts during the storm Fri/Sat but being November and dark already the battery was empty (we plan to tweak the settings to reverse some battery for the next power cuts, we had 30 last year!) Heat pump size has a big effect here, and that is based on insulation (especially wall insulation vs uninsulated solid walls and windows) - assuming here that loft insulation is topped up as needed for the heat pump BUS grant. So 8kwh heat pump vs 15kwh heat pump dramatically alters what electricity you need from autumn to spring. The gateway for off grid needed to be near our consumer unit, which is actually in the lounge, we have the gateway outside directly through the wall to the consumer unit, it is I think 30-35cm deep, not that big and wall mounted under a canopy (rainfall is heavy here, and we get wind driven rain from that side, it is IP 65 or 66 rated. Panel choice Vertical panels aren't as good because they don't get as much light as roof panels. Integrated solar (that looks like roof tiles) generates maybe 10-15% less than "on roof" but are far better in strong winds and there is easier cleaning and maintenance with no need for netting to keep birds from nesting up there. I think your roof surface area calc are most likely too high because it depends on the panels and what sizes are available plus manufacturer clearances from the edge and working around any chimney. If you want to work it out, we just had Viridian Clearline Fusion panels and the sizes and specs are online. Wifi If inverters or batteries are in garage or outdoors then check the wifi signal because although you can do fit it and forget it being able to monitor it and checking when it is at peak so you can run washing machine, dish washer etc will save you from drawing from the grid when out of battery. If you don't have wifi you need to run LAN cables to your router, and possibly between consumer unit and batteries, and have a system allowing a LAN connection. Our installer was crap with commissioning (I was literally reading him the manual) and tried to convince us to "just try wifi" so we had to insist on LAN. EV charger Worth getting at the same time if you don't have one yet. Photos 1. SolXpect forecast graph for week of Nov 16, 9.8kwh system on SE roof in west. 2. Electric bill from mid Oct - mid Nov compared to last year shows 50% less usage, it does not including export to grid but unless we want to pay ££££ we can only export 3.6kwh at once (40% of what we could generate).

I'm actually now thinking it isn't a seal it is actually clear silicone underneath it as it doesn't all look the same shape!

This is our kitchen sink and we had a real smell. Took out the thingy thing highlighted on the pic by unscrewing it and 🤢 Cleaned it all out but the silicone seals are not great on the metal thingy thing and although it is sealed and not leaking I could probably do with replacing the complete bit but I have no idea what model of Franke sink it is. Can anyone help me get the replacement bit or identify what it is called so I can buy one please. (It doesn't look great on the pic as it is difficult to get back in as the seals are that damaged and disintegrated although it isn't actually leaking underneath - yet)!

Is that considering the utterly dreadful efficiency of 50-60% of a CCGT - I get your point about transmission issues (and losses) for gas supply but I'm running a gas boiler at 97.5% efficiency on CH and 89% on HW What about the electricity transmission losses?

OK I had the system drained down to do so other work (it was planned for summer but well life gets in the way) Work 1. London loop on the HW outlet of the tank (early days but it already seems to have reduced standing tank losses) 2. Re-pipe the bypass so it's after the CH zone valve (it was before so when I restricted the flow thro the HW tank coil it opened the damn bypass and defeated my efforts to slow down the flow thro the coil!!!) 3. Combined 22mm Feed and vent for CH (removing the old 15mm feed) - Thank You @John Carroll it's solved all the issues with air ingress and got rid of another pipe in the cold loft 4. Generally remove a load of joints (from previous versions being adjusted) and clean up the lagging 5. Convert all the main rads to TBOE with Danfoss RAS-B2 flow control TRV bodies Anyway what I needed to say was Immersion stat is set to 55 Deg C (well mid way between 50 and 60) After heating it overshot by a large margin - Tank temp at the top was 60 deg C when it cut out 1 shower later and tank temp at the top was down to 50 and the immersion cut in again Turned it up to 60 because bath night and top of the tank was nearly 70 when the immersion cut out She hadn't finished pouring the bath before the immersion fired up again top of the tank was reading 60 So I'm guessing the temp sensor is lower down the element. Can't do any more tests because the system is now refilled and I'm back on gas and I've finished lagging what I call the plant room (Others might call it an Airing cupboard) Just to be clear - the water damage on the floor is legacy from previous occupants When I replace the tank I'm probably going to replace the floor as well because it's quite crusty

It needs to be strong enough to hold a gate post and strong enough to bond to a gate post fitting

Yes that right, english imperial 45 gallon/ 205 litres

Wow! you recon they will come out just to fill 2x 45 gallon drums, I wonder what the cost of that will be