SimonD

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.

It really depends on your budget. Stiebel Eltron, and Nibe both do heating and cooling and are very nice units. Viessmann currently requires an indoor unit, but also very nice and some of the best controls in the business. My Viessmann rep told me there is a monobloc coming, probably in the Autumn. Panasonic also do some nice units with cooling and these can be paired with their fan coils. And as you've listed, Vaillant. I think Vaillant is probably the cheapest on this list, but there may be a Panasonic about the same price. Most people like and choose Vaillant because of the standards of support available. Daikin also do cooling but I don't know much about them as I'm not an installer for Daikin and haven't had their training.

Why are you trying so hard to make the discussion so unpleasant and personal John? All I've done is quoted what you've said and reasonably replied and questioned it, and asked you for some data. It's just very curious.

It's a shame there isn't more granularity, but definitely interesting to look at the behaviour of the system and charts.

This just gets weirder and weirder, as it seems you're trying to prove a pointless point, so probably not even worth engaging in further discussion. However.. Sorry for confirming what I said? So in @jack's case, I can presume that the UFH works well to keep the upstairs warm in winter, but from the charts, shows it has no effect on upstairs for cooling and as he says 'unsurprisingly.' This demonstrates it isn't a whole house cooling strategy, even if it does provide comfort downstairs. Forgive me if I'm wrong @jack? Like I think I've said a couple of times in this thread, cooling is difficult to define, and must be defined and quantified as well as it can be so everyone is on the same page. It's fundamentals like cooling what (how big), by how much, for how long, etc. that need to be determined, understood and agreed at the outset, even in a short conversation like this. And then being explicit about the system parameters used to achieve the aims. In your instance for example, we don't know what kind of heat input your system is dealing with when you make your claims, is outdoor temperature at 21, 23, 29, or even 32C, what are the heat gains such as through windows or elsewhere. What temperature are you seeking indoors? When does your house actually start needing the active cooling input for your comfort? What actual kW heat transfer is your system able to deal with during cooling? What time periods are you running? I think cooling design is just as much of a heat loss & design task as heating. Which is why I asked for data, as on the data, I'm very happy to change my views, which are not based on 'my' theory but standards, calculations, and some knowledge from the wider industry. Views and passive cooling are not mutually exclusive, and my comments about passive cooling are not a criticism of your design decisions. I add in my comments about this as I hope it helps self-builders in the early stages consider heat gain and how to deal with it in the early phase as there have been plenty of threads over the years where this has caught people out, and following completion have struggled with over-heating.

My comments are absolutely justifiable in the context of this discussion. The discussion was about heat pumps that are designed for heating, not heat pumps that are designed for cooling. Yes, they're both heat pumps in so far as they move heat from one place to another, but a heat pump does not function in and of itself without a wider system that is designed either for heating, or for cooling, or as we've seen recently heating with some cooling capacity. This is where the conversation started: Then @saveasteading asked a question about cooling to which I answered: Here, you can clearly see that I'm actually using a distinction between an ASHP (implied for heating) versus a split a/c unit (which is also a heat pump), in the hope that it would help to clarify the difference, but clearly not. However, despite going round the houses, @JohnMo then confirms exactly what I said: As for reversing valves, yes they exist and they're used in ASHP designed for heating, but often the reversing valves have slightly different designs for the purposes of either mainly heating or mainly cooling, and they have different control strategies. So the fact that an ASHP heat pump for heating can reverse cycle, doesn't mean it's going to be great at cooling, or that it can do cooling at all. (and then approach to the design of controls is yet another matter where there are differences between 'cooling' and 'heating' based manufacturers in how they implement heating controls) But beyond this, the cooling effectiveness, as I've clarified above, of a heat pump for heating, is dependent upon the design of the whole system, not just the unit. And a system designed for heating has multiple drawbacks when it comes to reversing the flow of heat, due to a number of factors. Hence why what we're seeing here is exactly what I said - a reduction of a few degrees that increases comfort, but if you're in a position where adding cooling requires a huge amount of investment in infrastructure etc. to make your heating heat pump cool, you're better off installing a multi-split, which is of course is a heat pump, but it's a system designed to do a different thing mainly and would be far cheaper. 😉😏 But like I also said, fundamentally, you're probably better off designing passive cooling strategies into a house at the design stage....than relying on the heat pump, except for in exceptional circumstances.

Yes, the concrete floors will help a lot, but I'd be curious to know how the floor temps are when the ASHP is not running? Have you taken any comparative measurements? What we ideally need are specific figures to understand the W/m2 can be gained from a floor during cooling