SimonD

I know why you want to avoid the cloud, but for a little compromise and a good few grand saved, I have to say that Claude Code is probably at the front right now. Have you tried it? I've tried Deepseek, which is pretty bloody amazing too but the way that Claude can build an entire stack, spit out all the relevant code in files, plus the debugging capability just has me flawed. The other advantage is persistent memory across conversations and chat history, including file retrieval - so you can put in all your skills and provide a context that gets updated as you work. Deepseek gets a bit of a pain because as soon as you notice the context memory starting to degrade, you've got to create a new prompt with current context and paste it into a new chat. Really don't get on with ChatGPT. Last summer when I was designing a DB schema and doing it the good old fashioned way with manual normalisation etc. it was just taking forever. Put my requirements in along with a decent prompt and it spat out the schema in about 3 minutes including all the relationships keys and foreign keys in an svg too, plus it then writes all the sql. What's amazing is then how it points you to tools available and takes you through how to integrate and implement them you'd never have heard about without weeks of trawling various tech sites. It is absolutely incredible. Do you not find that you still have to do a little stitching in of code and a little nudging for debugging though? So you need to make sure the code is properly commented - that's been the thing with Claude for me is that it makes sure the necessary commenting is in there - Deepseek stitching in was a bit more painful as the line numbers it gave me were always quite a way off, well actually a lot as I still have a 3/4 finished app on there and I can't quite face going back to resolve the bugs right now. But I think with all these tools, you still have to properly keep them on track as they do tend to forget stuff and when you're dealing with mathematics and especially applied physics, you've got to be very careful.

Global radiator library now added which include Stelrad classic compact catalogue and Kartell K-Rad Kompact - all from K1/Type 11 to K3 Type 33. More to come from other manufacturers.

I bough one of these when we started the built. On mine the sides and front fold down flat for extra carrying capacity. Can't believe how useful it's been:

Of course there will be a lack of design experience as the ducting design is an HVAC solution, piped fan coils to each room are not. And of course, this then needs to be integrated with any MVHR system to provide sufficient cooling and heating flow rates which ventilation alone will probably not. The problem is one for ventilation designers, not just an ASHP installer. So here we've got the crossover in relevant trades.

Ducting runs? What kind of fan coils? Should be water connections and a condensate drain.

When you say you have gone through this with the builder, who is doing the heating system design and installation? Is it someone sub-contracted by the builder you don't know or is it someone you have brought in yourself? I'd like to understand the rationale and figures they've provided. The only significant price differences should lie in the heat generator & cylinder specifications, so time to do some digging for real world data.

For me there are two major strands here. First is that to really properly develop tools using AI you need domain specific knowledge - not only in terms of both functional and technical specification (because in my experience AI misses this and can very easily run away with itself in some rather bizarre ways and totally forget the original specification, even when taking into account context window and memory degradation), but also in terms of the domain of development - you have to be able to properly and fully sense check outputs and assumptions made by the model. If you don't have the experience, you're going to miss not just major stuff, but the important nuances required in good development. There are definitely problems with how knowledge gaps will develop from short-term profiteering. Second is that I see it as something similar to the 1990s off-shoring of customer service call centres to cheaper locations to eventual great cost and a requirement for brands to re-onshore those services to keep customers happy, or at least provide decent escalation routes. Although it still does happen it was largely a failed endeavor. A lot of what is happening in AI is the same and I think it will bite back - I've already developed an allergy to those cheap horrible customer service bots/agents that never actually answer my question. But on a much larger and equal scale, I think the realisation might be something along the lines of the long term costs of off-shoring all our industrial and manufacturing facilities, knowledge and capabilities. In the UK we've done this in favour of financialisation and services and it's coming back to bite us now. I see this as being the fault of hailed people like Dyson who had a very patronising and blinkered view of offshoring back in the noughties. I remember listening to one of his speeches where he was ever so confident that off-shoring manufacturing to China was nice a clean in that it wouldn't involve any transfer of IP or high value knowledge, as it was only the low value stuff they'd get - oh how wrong he was. So the more we indiscriminately off-shore to AI the more we're going to create a rod for our own back. None of this is to say the AI is universally bad. I use it all the time and it helps me a great deal to get things done in a myriad of ways. Just need to know where your off-ramp is for when it merely gives you the impression of benefit.

That's a good point!

Viessmanns always sound too big because of the way they label them. Go and double check the specs directly from either Viessmann or ViessmannDirect because IIRC the 8kW 150-A has a rated output of 4kW at A2/W35, 5.6kW at A7/W35 and 6.5kW at -7/W35. At 7C it'll modulate down to 2.1kW. The output range is 1.8-6.8kW. The 6kW unit does about 5.5kW? at -7/W35 I think. Somewhere there are nice charts published by Viessmann showing performance throughout the operating range at min and max outputs which honestly show the reduction in output between 5C & 0C. I don't think your designer is that far off, but slightly hedging bets on the defrost.

Oh dear, I'm under scrutiny 😁 I'll have to remove drawers and stuff, but yes I totally agree on that blocked kitchen sink stuff - I had to blow out a blocked condensate drain once and that was enough for me to stipulate that'll I'll never do general plumbing! I lost a customer over this too. I visited to fix the boiler and the customer had cleared out the cupboard under the sink and said, while you're here can you... I gave him my minimum price and told him it was this price because I just don't do this work 😏

All good pointers, thanks. I will dutifully strip it all down and clean with associated PPE!

Good question. It's not actually the same as you get when you have an open end to a soil pipe, it's a slug of smell that actually slightly in taste.

My kitchen waste is causing me a headache - it's smelly and getting worse, even though I've tried to fix it. Originally it wasn't smelly and all was good. It began smelling only when the dishwasher was started and did it's first flush. Just in case I installed an anti-siphon trap at the sink. Not change. I then went to the soil stack boss and double checked it's all sealed up and layered on some extra solvent weld and did some general checking of joints, which all seemed good. I thought I might have resolves it, but no, the smell is worse than ever. It's an internally routed soil stack with an aav at the top just below the very high ceilings. The waste pipe boss is a normal strap boss with rubber (could the problem be here despite double checking?). The soil pipe does a wiggle through steels - this is my only know sin with this installation as I used a flexible connector to meet the soil pipe below the floor, which goes into a push-fit soil pipe. The smell is no noticeable in the ensuite below where the soil pipe is exposed so I can try to work this out. My suspicion is it's either something to do with the strap boss even though it seems to be properly welded in there, or maybe the aav at the top of the soil stack? I don't think it's the flexible connector unless it's split where it doesn't allow fluid leak. Help....

That is one hell of a sentence @John Carroll!

Yep, spot on. Thanks for the link. I completed an installation last Autumn where the old house had 600mm walls completely uninsulated but had been extended with some new walls insulated. This property is heated absolutely fine and the owner says they've never been as warm and comfortable in the house. There's has a 9kW heat pump with calculated heat loss of 6.9kW and I took out a 32kW combi. Interestingly it did take 2.5months for the fabric to warm up - the weather comp curve was a bit all over the place and then suddenly it just settled down to run smoothly. I have used heat loss data derived from studies by some different organisations like Society for the Protection of Ancient Building etc. and recently BRE published updated tables for the calculation of stone walls etc. which bring down the u-values quite significantly. At the end of the day it is simply about the balance between heat in - heat out and the correct means of distributing it around the building, and if you get that right any old building can have a heat pump and benefit from it.

I see them and fix them all the time. Like I said above, it's unlikely your multi-bloc, but the supply pipework to the uvc that's the problem.

I think there are 2 angles as to why patents a generally a joke. 1st is if you're a small player and someone doesn't care about infringement and in particular they're in a different jurisdiction there's very little you can do without a very big legal purse, if that's even enough. 2nd which is more to do with innovations is that they're increasingly being granted for stuff that really doesn't actually fit the proper definition for something worthy of a patent and unfortunately the tech industry seems to be one of the worst sectors for this - especially in the US of A. About 18 years ago I developed a new product and the bar for granting a patent was pretty high - i.e. it had to demonstrate that it was an innovation and that the improvement was not something obvious to others skilled in the same technical field, and of course that it hadn't been previously shared. Now for my part, putting a cylinder in a box together with a heat pump to sit outside is hardly earth shattering in terms of an improvement nobody in the industry could think about. Maybe they've drafted it well enough to obscure this? But, at the end of the day, the commercial reality may be the biggest challenge. They are going to need a serious amount of money. As a comparison, Ideal Heating received 5.2 million from the government plus the company itself invested 6.8 million to upgrade its manufacturing plant for heat pumps in Hull. They've already got the manufacturing resources and know-how and someone I knew years ago who owned a company that designed and installed manufacturing production lines in the automotive sector developed a new product - in his situation volume wasn't high enough for the Chinese to be interested so he had to struggle to find the resources in the UK, again even with his knowledge of the industry - this was back in the 2000s. It's not my intention to come across as negative, but it is a mountain they're climbing. This is the reality that killed my product - the testing and production resources, even though a UK manufacturer had agree to help me with all the prototyping support and sucking up some risk their end.

I know, I worked in the tech startup scene, including in Bristol, for over a decade and ran workshops for leaders in startups looking to scale from about 7m in annual revenue across Europe. The patent is just pending but to me looks like a bit of a joke when you look at what patents are really for. This is a patent application that proposes the adding a thermal store into the heat pump housing - it stretches the 'inventive step' but then patents have been a bit of a joke for the last few decades. Don't get me wrong, they're doing something good, but in reality it's just another heat pump offering with a slightly different approach. I do wish them luck and hope it goes well, but is the IP strong enough to stop the really big players or pull them in on a license deal? They'll need to have a lot of funds behind them as I bet their burn rate is pretty steep - it's not a cheap area to be developing new products in (unless they've got some backing from a large company already, but then the team would likely have a different shape). 1m in investment it positive, but it will not go very far at all, but hopefully they'll get a decent proof of concept from it to support more rounds of funding.

I don't think you'll see any difference whatsoever by upgrading the multi-bloc (inlet group) - which I presume is what you're referring to? - to 28mm. By far the best solution if you don't have sufficient flow rates it to upgrade/modify your supply pipework - and we know you've got some design issues there. My experience is that the multi-bloc units cope absolutely fine with anything from 6l/m to 30l/m. Where I am, I don't see any supply rates much above 30l/m from the mains. Some of these have regulators that provide the same pressure whether there's flow or not. If you're replacing the multi-bloc, you need to make sure the pressure relief valve has the same pressure specification as the manufacturer supplied unit - e.g. 4.5bar or 6bar You should use the balanced cold for any mixed outlets because imbalance in pressure can cause problems in these fitting - e.g. where I am mains pressure can easily be 6bar so if you don't balance this you have 6bar at one side and 3 bar at the other. I always install and use the balanced cold as otherwise I'm installing another prv after the stockcock.

Good ideas there. They look like they have a very good team for development. I just wonder how well resourced they are to build it and scale, but looks promising. I really do wish we could change the record though and stop trying to make every new heating solution like a gas boiler and instead try to build a new message around the transition, but I suppose with so many people still harking on about North sea oil & gas, it's an uphill struggle.

I've seen much worse. I recently completed an unvented installation where I tested one of the outside taps and had barely 10l/m and it was only 2m from the rising main. There was another outside tap more than twice the distance giving me nearly 30l/m. It seems some plumbers have lots of excess fittings they want to get rid of and waste time making repeated visits to the local plumbing merchants counter. It also seems to be a rare thing that plumbers properly considers pressure drop. Really what you want to tell your plumber is to not use any fittings at all and plan the routes accordingly - use MLCP/copper with a bender or use cold forming bends with plastic push-fit as a priority. Your other problem appears to be that you've got 15mm off the 32mm MDPE, which really should be upgraded too.

It's funny, I got sucked in and read all of that. For me, when I was working in tech and in professional services I was primarily a system designer, whether that was an IT system or a system for effective knowledge transfer and exchange, so I particularly liked the last part where it's very correctly pointed out that the physics can isolate systems that are interacting in a complex way, in order to simplify the calculation, but of course in heating a home we're looking at multiple dynamic systems that are always interacting and creating a wider system. This is one of the reasons I get frustrated with heating system design as it's almost ingrained in the industry to design for and then quote a system according to its 'flow temp' or a set 'minimum room temp' - a customer recently asked me what flow temperature I had designed for the system and why I had applied a constant temperature throughout the house. I explained that the flow temp should correctly be constantly fluctuating according to demand and that the changes I'd proposed also have redundancy and resilience built in to accommodate future changes and developments in requirements. I recently raised this question with a highly experienced engineer and designer, when I was presented with an example calculation to show how hydraulic separation doesn't necessarily create system inefficiencies. When I asked about control mechanisms and how a dynamic system responds and behaves following constant modulation, the response was silence. We still have a long way to go to properly understand these interacting systems because most complex of all is how the human body responds and finds comfort within the system.

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.

Maybe I've missed something but that linked document appears only to outline a revised Cfd arrangement. Where is the gas marginal pricing de-linking mechanism? And for taxing extra-ordinary profits? Why not just cap the profits in the first place?

Is it that Panasonic are not being helpful for him or for you? So far my experience of Panasonic tech (I'm a Panasonic pro installer too) has been very good, and when I needed an extra push for some assistance, my rep was amazing and followed through on all promises. So I'm a bit surprised to hear this. The problem is that we really need to know more details about the design issues and what they're referring to as much more power, which will depend on the design parameters too.