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As I have discussed on earlier podcasts and various topics, I have a Willis-based configuration for heating our low energy house, and control is implemented with a dedicated Raspberry Pi using a custom NodeRED application for our underfloor heating and SunAMP-based hot water. This system logs a lot of instrumentation temperatures every half hour and also any significant events such as turning on and off pumps and the heater. Our electricity supplier has been OVO for the last 4 years, and because we have a smart meter, the control application also includes a script to log on to the OVO Portal and download the daily usage data into the MySQL database. Because these latest energy hikes, we have decided to revisit the issue of whether it would now be cost-effective to install an ASHP in order to save on monthly electricity costs for heating. Because I have been logging all relevant data for the past 4 years, I can base this decision on hard actuals rather than some generic planning assumptions. The next two graphs summarise these results. The first is an analysis of our daily energy use (we have an electricity only house). What I have done here is to aggregate the 4 years of data by calendar month and split these into three categories: Underfloor Heating (34% or ~4,000 kWh/yr). In practice, we only heat off-peak and use the thermal mass of the floor slab and the house itself to smooth out the overall background heat levels. As I have discussed in other topics, this results in a temperature ripple of about 1°C which is quite acceptable given the reduction in overall all heating costs. Other Off-peak use (25% or ~2,900 kWh/yr). We also use a couple of small oil-filled electric heaters on the first and second floors for the 4 cold winter months. These output roughly 1 kWh and run on a timer (actually controlled by my home automation system). We find that 3 or 4 hours is typically enough to keep the upstairs acceptably warm in the coldest month; this also means that the UFH on-time doesn't need to run over into peak periods. Our resistive load white goods (the washing machine, dishwasher, SunAmp DHW) are timed to come on in the off-peak period. General Peak Rate use (39% or ~4,500 kWh/yr). Pretty much all of our baseload and direct hands-on devices: fridges, freezers, cooking, computers lighting, etc. Note that the 2 retired (out of the 3) occupants of the house spend most of May, June, September, October abroad; hence the dip in this general use figure. I find the annual variation on this base load a little intriguing ,and I am not sure why it is so high. Our live-in son often has his radiator on in the evenings when he's at home, and we do spend more time indoors in the cold dark months. The simplest ASHP implementation would be for slab heating only and would give a CoP of ~4 (as the circulation temperature is under 35°C) hence saving perhaps 3 mWh p.a. @ 18.86p/kWh or roughly ~£560 p.a. at our currently quoted OVO night rate. Given that we would need to use an MCS certified installer to exploit a permitted development waiver, I would expect our installation to be £10K or higher, so I still don't have a viable cost benefit case to go this route. Yes, adding pre-heat for the SunAmps would increase this annual saving, but this would complicate the installation, and given our volume of DHW use this would in fact worsen the cost benefit case rather than improve it. Another interesting point is raised by the following graph which I pulled from a 2014 Thermal Design post. The bottom line is that thanks to entropy, pretty much all of the electrical energy that we use ultimately ends up as heat within the fabric and airspace of the house. Given this, the overall heat losses (if you take December for example) are pretty much double what we originally estimated. The following can account for the majority of variance, but not all. We had to drop the U-value for the warm roof to minimise ridgeline heights keep the planners happy We added 60° reveals to our fenestration to improve overall light levels given the planners putting hard limits on our window sizes, and these some limited thermal bridging Winter solar gain is almost non-existent for our window configurations. As discussed in an earlier post, we had a cock-up in our slab design which created a thermal bridge between the inner ring beam (this supports the frame) and the outer ring beam (supporting the stone skin). We could only partially mitigate this during slab pour. We estimated that MVHR would have a recovery efficiency of around 90%, but looking at the inlet temp vs room, I estimate the actual recovery is nearer to 80%, that is double the heat loss. We run the internal room temperatures a couple of degrees warmer than initially planned. However the house is built and well established so getting any convergence is now unlikely. So the house performs as a low-energy one, rather than a true zero-energy one. And we still only put ~20kWh into our slab in the coldest months.

I think it's just a normal/common issue. Apparently sealer does help glue the sand together. I've also read of people brushing in a kiln dried sand with some cement added to make a weak mix but think this can stain the blocks.

Just a few progress photos of the inside and how its been moving along since the builders left after completing their work: First job was the warm roof, literally just to get some of the 100mm boards used up as i had no where else to put them I was also trying to get as much of the dusty bits out of the way before opening this room up to the rest of the bungalow, so removed the outer bricks from under the bathroom window (the blocks will be done later down the line, as the new bathroom needs creating first so i'm not without showering and toilet facilities). Cleaned up under the floor and removed the old kitchen window, door and brickwork. 2 new windows went in, triple glazed, with just the bow window to swap out for a standard casement window later down the line. Next task was to get a firm floor to work off, so I set about getting all necessary pipes in, and also got the electrician in to sort the sockets out, and finally another load of insulation, trying my best to use up all my bits rather than skipping them A further 50mm to the roof and 20mm under it: Followed by airtight primer and tape round all of the edges Started working on the box section at the top of the roof which will house the ventilation pipes and cover up any thermal bridges from the timber wall header At this point the building inspector came, and asked me what on earth the pipes were for?! Told him they were for the mechanical ventilation and he looked nonethewiser, but otherwise was happy for me to carry on Another satisfying job using up all my odds and ends of plasterboard this time! Before the front of the box goes on, i need to cut out the 125mm holes for the vent pipe to come through, and install the plenum at each end. Also found a use for the spare render beads i had from doing the dining room (part 1), trimmed them down with the planer to 11mm, which will give me a perfect level base to work from when i put the bonding coat on. Fingers crossed the next time i post, it'll be more or less done, minus the bathroom end.

I’d do that from a cherry picker - easy job. I would check though that the corbel course isn’t the lead soaker course too - if so I would want to keep the course above and then cap with a mix with a waterproof agent in the cement and also fit a vent pot.

Pick a float up and see if a pump triggers, if yes then try other one for peace of mind. If nothing happens power must be off and alarm could be power loss alarm

No specific need to attach timber into a UB or UC steel, depending on steel section size and joists being fitted it can be easier to fit into the web and sit on bottom flange. Flitch beams look great if on show and are easy to put together but need to be deeper than a UB or UC for given span and deflection

Not necessarily, you could fit the timbers into the web. Saves having joist hangers.

Thanks @jack and @JohnMo I’m in Norfolk, I’ve not had my heating on yet, my current house is not as well insulated as the new one will be. according the the spreadsheet my heat demand was same as yours JohnMo 3.1K @ -5 Good idea with the waste water heat recovery Jack

289 m2. Your U-values are good. It's possible you might meet PassivHaus standards (which set energy consumption targets rather than insulation values), depending on other factors such as solar gain, windows, form factor, etc. 5-6kW might be okay, but a little more overhead might be useful. It also depends where you are in the country - I imagine someone living in the north would have greater heating requirements than me in the south. One thing you might consider if it suits your layout is waste water heat recovery, which recovers some of the heat energy from showers while they're in use. Depending upon what proportion of the hot water water in your house is used for showering, the net effect can be significant. Some have argued that the payback is too long, but there are decent energy savings to be had, and they're about as set-and-forget as anything you can install when building a house. They do take some planning when it comes to drains.

Your house is very similar to mine, my walls 1.4, floor 0.09, roof 1.3, our heat demand is 3.1kW @ -5 NE Scotland. Our temps have dropped quite a bit more than yours. So much so, that the heating has been on since the beginning of Oct. Interesting is for the average temp in Oct, our heat demand should be 1.5kW, but so far this month we are averaging at about 20kWh a day including DHW. So about 0.6kW heating input. The only thing to watch for is look at the HP output at your lowest ambient, to make sure you have some room for DHW. If you are batch charging UFH, this allows a bigger HP to be used, if doing WC you will be setting back at night a couple of degrees, so you will have a few hours where the heat pump isn't doing that much anyway.

You could consider a flitch beam, using 10mm steel plate sandwiched between two timbers, bolted every 400mm. A fair bit lighter than an equivalent steel beam or column section and you can fit joist hangers easily.

Cut them down to 2100mm to match the top of your door architraves. That's what we did at our last place. Gives you a good 400mm to the ceiling and it looks right.

Turn off the stopcock and if the tap still flows, it can't be mains, it must be from the tap. Or simpler, do you hear the header tank refilling after you have run the tap? If so it is coming from the tank.

Worked for my DCC-enabled SMETS1 meter about a month ago; it's giving me an error right now though. Far more accurate than asking octopus support, when it's working anyway ^^.

You can usually tell if water if from a loft tank or the mains. If you can stop the water coming out the tap with your thumb over the spout, it is from the loft. If you can't, and you get wet trying, it is probably from the mains.

I gave it a go with my SMETS2 Smart Meter. Got the same response as you. "There has been a problem trying to check your meter. Please try again."

Water analysis should confirm the source of your water and its quality. Make sure they sample and test the water in a laboratory.

I think the general consensus is that solar thermal is at best marginal compared to PV. The latter has a much longer usable season, plus when the tank is completely hot, you can keep using surplus electricity for other things. If you're considering batteries, I think the maths is even more firmly in the PV camp. Perhaps the only potential issue is how much PV you have installed now, and whether your local network operator might object to you connecting more.

Dave beat me to it, not used jointing compound but it’s made fir the job I guess.

I guess it depends on what the SE decides, large glulams can be beautiful (IMO). Not sure about being heavier than a steel 🤔. I put 8 of them in a loft conversion once and just the two of us, no sweat.

If we assume a steel across the middle the rafters end up about 4.5m span. The old Trada table I have suggest rafters would be something like 47 x 220 C16 on 400mm spacing.

you could pressure wash it to remove as much sand as possible then replace with jointing compound, much better than sand/cement. https://www.travisperkins.co.uk/product/building-materials/building-chemicals/jointing-compounds/c/1529003/

+1, if you brush a weak sand cement mixture in when the gaps are wet but the face of the blocks are dry staining should not be an issue, it’s what I would do.

I think an SE would need to give advise on this, yes snow loading is a real thing (till we get some decent global warming 🤣).

It’s the sort of thing I would do without a thought years ago, older and wiser now tho. If the chap has the right experience and you think he is reliable then why not? I once put my scaffold tower on my car port roof to access the roof, got some funny looks but with a couple of acros underneath it was fine.

Just taking that pot off from just a roof ladder would frighten me.

At 6.5m a 9x3 will struggle to hold itself up and definitely not the rest of the roof plus a big snow load (flat roof and presumably insulated)

As a price it seems pretty reasonable, very easy to have a brick fall onto that roof tho.

yeah. new 32mm main direct from the pipe in the road. our existing supply off the water main in the road is shared with 2 other properties so I'm expecting a better pressure/flow. I'm just curious is all! just one of those things that my brain needs to know.

one of the jobs to do on my list is to check my static pressure and flow rate just so I can double check everything.

The thing is, you should not be drinking tank water anyway, your kitchen tap, at least, should be on the rising main, i.e. fresh mains water.

You could do this with a steel support structure(s) that takes the loads the stack currently takes. That in itself will need supported but will let you proceed without taking your house apart. Looking at the joists on the left hand side, I would imagine they could be caught with a steel running approximately where the stack sits, and if suitable, sit on the walls of the room that the stack is on - left hand side. Another steel or part of the same system will then need to pickup that bearer that keys into the stack on the right hand side. Go and find a friendly local structural engineer and set him to work.

My shower is around 16m away from manifold . 15mm pipe no issue

For cutting sheets of PIR I found the best way was a cordless circular saw. Sheets are too big and heavy to use on a table saw. Only 50mm cut depth but flip the board over and you get all the way through. With a bag or vacuum attached, produces less dust than a handsaw. Mask and goggle up, it's not pleasant. And do it outside. Overlap you floor sheets at 90°. E.g. put down 50mm sheets first, then the 100mm on top but across the opposite way. Then foam any big gaps, and finally tape the joins. For the roof, stick your 100mm between the joists, then the remaining 50mm or whatever it is under the roof joists, and fix down with battens and your airtight membrane. You might have a different detail to this tho. Oh, get that roof battened and slated before the first storm rips all your membrane off

Move that other bracket closer to the join as well, you will get movement at the join due to the rubber. Try to strap close to joins and then work away from that.

Robin Clevett and his various pals e.g. Skill Builder have a few Youtube tips. Alan

Goodness the quality of the UK government systems for its citizens is atrocious - and I suspect atrocious and expensive. For example, the land registry website looks like something from the '80s and as far as I can see you have to go through checkout for every single property you're interested in. Hmmm, let me see UK productivity is ... shocking. Why is that, I wonder? Alan

Same here.

Let us know what the water company say and do. We might be able to suggest the next course of action, if needed.

Looks great. just add a 10 KWH SolarEdge battery to our West Sussex home and waiting for solar PV. Looking at 11 400W all black panels. With this and Octopus Go we should be close to running on night rate most of the time.

It depends on the height of the outflow pipe and the make of AAV. This document gives details, under installation section, for Floplast AAVs which I used.Floplast AAV info.pdf

Why predict when you can measure! (If your existing smart meter is on DCC)

15mm copper of plastic? 15mm hep2o is only 11mm ID and, depending on how far away your showers are and what flow rate you want.. might be tight. It's one thing If your showers are close and/or you are good with 8L/min, but if they are 20m away and you are expecting 15L/min, you need to size accordingly.

No. Current transformers need either L or N but not both as their magnetic fields cancel each other out. You can get 13A plug-in type adaptors if your ASHP is terminated in a standard 13A plug but that's extremely unlikely.

Of course. Us professionals cannot possibly allow you, as a newbie, to get this right first time now can we?! So; OK. The rest bend will eventually fall off. Do as Bruce says above, and clamp that well. The shoe on the bend is supposed to be where the thud gets arrested, but that’ll be off before you know it

Fence posts done over the weekend! We got them from Kedel with a pointed end and round flat top 1.5m in length and almost half of them buried with sheer force knocking them in. I ended up driving to them to check out their products and discussing exactly what I wanted and they drilled them 20mm hole for the rope (extra cost) then I got a man and van a couple of weeks later to pick them up (their delivery fee is a rip off). They were about £13 each including the drilled hole. Got some rope from Facebook (someone bought 32m from Rope Services) and we got it very cheap. It's about 30 metres in length. Ignore the paving as we will be redoing it. Had to lay some turf where I got up some of the paving flags. . VID_20221023_172932.mp4 VID_20221023_171947.mp4

I used the XR4000 hopefully someone more knowledgeable will be along to explain if 150mm @ 0.022 W/mk is better than 100mm @ 0.019 W/mk I’m guessing it is but hopefully someone will confirm. I went with 200mm in 2 layers of 100mm to aim for a 0.11 U value

+1, I must get a clamp to see what it is drawing on standby, I guess that will tell me.

It's wired on output NO6 from the Carel pCO - a switched 230 output. Easy enough to disconnect if it's an annoying parasitic load.

Floor sensors aren’t good to stop extreme temperatures - you need to isolate that issue at source and put proper blending valves on the manifolds. When running multiple rooms in a zone I prefer to use the Salus auto balancing actuators as they will regulate flow and temperature - you then just need a simple (programmable) thermostat per zone and wire it to all the actuators in that zone. as others have said - upstairs will be 1-1.5°C warmer than downstairs and MVHR will not move that much heat around.