All Activity

No need to panic! They are definitely going to do room by room calcs, all mcs certified. We're just at the initial design phase so once everything is firmed up on that will proceed to final design with full calcs. I was reading about your program and it looks really good - once I get time I will have a go with it for our design and give any feedback I can.

I did 2 undercoat and 2 top coat on mine, primed any bare areas first and produced a lovely finish. You need a depth on MDF or it can show through any imperfections, do it once, do it properly i say

Isn't that the current situation in Scotland loads of wind, hydro etc, almost zero electric comes from gas, but unfortunately our pricing is driven by English policy. In fact SNP use that as a reason for independence.

Not visible on my phone, so I think you're right. I'll post it again tomorrow when I'm back at my desk.

Lots of panels on a G98 inverter, massive overclock is the way to go. Easy no permission needed, just a G98 notification. Self consumption is fine in theory, in practice difficult especially in the summer, you just end with loads of hot water you can't use. Just go with Octopus and pay £250 and get the export (wish I did it 3 years ago), East Suffolk you will generate tonnes of energy even with a 3.68kW export limits. My advise, self install as many panels as you can to stay within the max voltage limits of your inverter, it's cheap, spend £250 to get with octopus. Export everything you don't normally consume.

Panasonic will also do a heat loss calculation as part of their design so they can size the correct unit

Hi lizzie ive just gone through this process with Panasonic and our installer. I wanted the setup you are aiming for - UFH as zone 1 and fancoils upstairs on zone two. Everything I have read on the system points me to it being well designed and totally capable for what I want. The weak link was indeed Panasonic uk design. Eventually I got the contact details of the design team themselves and liaised directly with them. I don’t think many people in the uk use the two zone setup so it took a while to get the design so we all understood it. The benefit is that they produce the full hydraulic and electrical design (not that straightforward) AND then warranty it. So if anything is incorrect Panasonic pick up the tab. Your installer just follows it. the rep was useless and just tried to sell me aircon. The best thing to do is strongly suggest that the design team follow Panasonics own reference diagram which you can find in their main manual. Can forward if you need. The Panasonic control unit is fairly smart and supports multi zone by way of controlling a mechanical blending valve and water temperature sensor. In cooling mode this is what protects your UFH from running too cold. Return water is blended to mix up to a limiting temperature (say 16 degrees). Fancoils can run at 7 or 8 degrees which is what the buffer will be chilled to. You can even do the reverse in winter and have your zones on different temps if you want the fancoils running a bit hotter ( probably not necessary). All my pipework was lagged. In theory it should be as good as aircon. PM me if you want the email For the guy I spoke to at Panasonic. It’s a very capable well designed system though and only one I came across that natively controlled multiple zones, had the fcus from same manufacturer etc. and the tcap range is very impressive in the way it can maintain a constant output irrespective of environment temperature.

We ended up with TECE cisterns. Quality seems very good - no issues in operation, very quiet. Instructions are those awful wordless pictograms so sub-optimal but just about workable.

Some Stanford Prof, I forget his name, predicts that we'll eventually get massive over-capacity in renewables and thus cheaper power prices eventually. Don't heckle me, it's not my idea. However, if a bit of that is true then the peakers will be used less and less over time and therefore gas will eventually become less of an influence on electricity prices.

Hang on, serious alarm bells going on here. What has your installer done? The installer cannot complete a proper system design without a full heat loss calculation. Whatever anyone else tries to tell you, you absolutely need a proper room-by-room heat loss calculation to inform your system design. To plug my own tool again - you, or your installer can produce a proper one to current standards for free at openheatloss.com Not at all Nick, rooms will by their very nature have varied heat load requirements due to lots of things like exposed area, perimeter length/area ratio in floors, size and shape and they all need sizing according to their individual needs, otherwise you'll take a hit on system efficiency and comfort, even if you design for 21C across the whole house.

In this recent video, there's a couple of comments that I'm not sure I quite get. Here's a link to the video: Why Are The DNOs Limiting Your EXPORT And Even Your INVERTER SIZE? https://youtu.be/Bvpl9pvg8zk?si=4rLhJ-me57Pcwabu Here are the two comments (I've highlighted the relevant bits that were raising questions for me in bold): >>> One detail - only grid tie need approval. If your system isn't capable of pushing power into the grid (that's not capable as opposed to "set to 0") then you sidestep it at the cost of no export revenue. Setting up a big non grid tie inverter and putting the house on that with the grid as an input (generator basically) lets you side step all the mess in the difficult cases. It's not usually the best option but if you are getting 3.6kW and especially if you are also refused G100 with a bigger inverter it's definitely worth doing the maths on houses where you want bigger batteries and inverters, and remember it also lets you avoid the MCS costs too. I am guessing plug in solar is going to make it even more of a circus especially if they got 250,000 G98s submitted the month it goes legal 😎 Our setup actually has some grid tie with grid tie batteries and solar, and some non grid tie with other batteries/solar that runs the heatpumps and some other bits. It was the only way to make this big old building work within the allowed G99. <<< >>> The inverter size limitation is to do with failure cases with export limitation. If they calculate that the export limit fails, and the resultant voltage would exceed legal upper limits at your house, and your inverter voltage shutdown protections also fails, then they impose a choice: 1. Stipulate Inverter size limits, 2. Provide a quote to the solar installer for reinforce the DNO’s network so that it can accept the higher inverter size (often many thousands of pounds). At my house, I have an 8kw inverter with a 5kw export limit. When exporting 5kw, the voltage is about 247V. So there is some headroom between the export limit and the upper legal voltage. There are two a get out clauses though: 1. Install a 3.6kW inverter, but with 7kW Maximum Power Point Trackers. That enables you to hookup 7kw of solar, and at maximum power: 3.4kw can be fed to a dc coupled battery, even though the AC output is limited to 3.6kW. Sunsynk offers such an inverter. 2. Don’t connect your inverter to the grid. DNO’s only have jurisdiction over connections to their network. They have no jurisdiction over off grid systems. You could have an 8kw+ inverter supplying your house off grid. Then you can choose whether your house is connected to the grid, or your inverter, using a changeover switch. There’s no opportunity for export, or charge up with cheap overnight electricity though. <<< The reason I'm asking is that I'm planning on having a lot of panels and inverter power and self consuming as much as possible. I'm planning on over capacity so that I can make the shoulder seasons (i.e. spring & autumn) mostly self-consumption too. I don't really care about the export - I'm guessing the rates will continue to fall until it's a waste of time.

Have a TECE concealed cistern waiting to be fitted so can't comment on any direct experience of it. But on paper looks good and allows the flush volume to be adjusted and provides for a double flush. Cant recall the price but not likely a budget option. Full maintenance through the flush cover plate. Depends what features you want, and on ease of maintenance through the flush plate I guess. I do have a simple cheap plastic cistern on one toilet which is easily maintained by scoring through the right secret grout lines to then remove the worktop above for full access to maintain.

How much? 😬

I have had a plumber here today who has repressurised my expansion vessel on an UVC system back up to 3bar. Unfortuately he left for the day and is now uncontactable but we have a problem. Every time we run off hot water we are getting a very loud creaking noise from the system. Any help or advice on what may be going on and how to resolve it ?

Geberit. The End.

Something may have changed in the meantime, but Ofgem concluded the opposite back in 1999: "Another result from the modelling was the observation by participants that gaming - seeking to exercise market power - was perceived to be easier under SMP pricing rules than pay-as-bid" "Under a pay-as-bid system, buyers have to go out and find the best deal available, which will increase the competitive pressures on generators" "These points are supported by the business simulation modelling that has been conducted by the RETA Programme, where prices under SMP came out higher than pay as bid" The New Electricity Trading Arrangements, Ofgem/DTI Conclusions Document, October 1999, page 91 (SMP = System Marginal Price) Not sure what subsequently happened that flipped the position in favour of marginal pricing. It would be interesting to know.

Probably in your cache - I can't see it either

+1 for @JohnMo's comment. I too was a little confused about this so I spoke to a UFH supplier and they confirmed - it's just there for the commissioning/build period then flush out and replace with water (plus inhibitors/biocide if you feel the need).

Umbrella route has been done by many. But everything is done via umbrella company with respect getting grants and paperwork, you do the work and report back, they may need to commission also. 9kW sounds big based on your other posts. If it's an R290 Grant, they don't do cooling. Have it confirmed from Grant technical.

If you are in the build stage and it's likely to see near freezing temperatures and the loops are being left water filled, yes. If no water in system yet, just pressure test with air and leave pressurised. But you could blow out the water and replace with air pressure if already water filled. If house is built and heating system in use, no point. But you do need corrosion inhibitors and biocide (from same company to ensure chemistry compatibility)

Someone has just raised something I haven’t come across so far - do we need antifreeze in our ufh?

That's odd. It's visible to me in both my post and where you quoted it in your reply.

I would like an effective zero disruption install. I think I could use a 9kw Grant Heat Pump costing 3.3k inc VAT run the cabling and pipework myself and even position the unit (total cost about 5k?) so it would just need someone to connect the electricals at the meter end, sign off on everything, inform the DNO, confirm it meets the BUS requirements and whatever else in order to get the BUS grant. Even without this would seem cheaper than the 6k after BUS that I have been quoted. Thoughts?

Really useful thanks @jack. I took a quick look at the Panasonic unit and on the face of it the specs look good and folks seem to have been able to integrate fully to HA using ESP32. Annoyingly the image seems to have a problem and won't load 😞

Don't forget, if you have an EV charger fitted, you also need an SPD under current regulations. To be honest SPD are so cheap these days I don't know why they are fitted as standard with a new installation anyway.