SimonD

No, it isn't. It's based in complexity, which physics seriously struggles with and the reductionist approach it has long held so dear really doesn't cope. This typical reductionism is exactly mirrored by your claim that it's based on basic physics and fundamental components - but the behaviours of the systems are based on their complex and dynamic relations. But, you've also kind of proved my point - you're making a statement that one small fraction of science is true science which indicates to me a misunderstanding of the scientific method and the philosophy of science itself. Science is actually about continually questioning whether what we think as true is really true and so moving forwards and that by definition this also involves questioning the basis upon which we think we know something. That is the scientific method.

I think you're flying a bit close to the wind here. You said you studied the philosophy of science? This includes epistemology and ontology - there is not just one narrow fixed definition of these, which is what you seem to be suggesting. But also the philosophy of science is about exploring the relationship between science and what we consider to be truth, and certainly not anything like that certain sciences are real - which implies they have exclusivity over what is true, which of course they don't, it would be pretty naive and ignorant to suggest they did. 😉 I'd also suggest that being fixed about what is real, is pretty non-scientific to begin with and ignores the very important metaphysical component inherent the philosophy of science. 😉

It depends on whether you're looking to rely on them or not. The problem with temp gauges at the manifold is that the return one will show a combined return temp from all loops so you don't know if your individual loops are running at the correct dT. The flow one is okay, but personally I have a mixture of clip on k-type used with a digital thermometer and some bluetooth ones that provide datalogging back to a specific app - at least for commissioning and maintenance use - so each loop can be properly balanced.

TBH, I think the article by Evan Davis was pretty fairly balanced, and the BBC the other BBC one is slightly cheaky as it doesn't properly go into why the ECO4 grant was amended. The reality is that if the heat pump is going in as a retrofit, the overall costs of the system are very high - and no, unlike many incorrect claims here on this forum, this is not purely down to grant harvesting. But figures like Dale Vince aren't helping by saying things like heat pumps don't work like they say they do, as he did in an interview yesterday, doesn't help at all. These are the kinds of statements that need clarifying, but just like the whole Net Zero thing, the general and popular coverage is fairly toxic and I have to say the industry isn't helping itself greatly right now.

I was driving through France twice last week and on one of the journeys the exterior temperature was shown as 41C - the a/c in the van couldn't cope and it was just getting hotter and hotter inside but it was a shock to the system to get out on a quick break.

Keeps on coming back to this doesn't it? Domain knowledge is first key, second is then how to translate that into useful prompts. I was playing with DeepSeek this morning and pretty blown away by how far it's come in a few months. It was fascinating that after inputing some questions, I explained I had domain knowledge and it they said that totally changed the situation and provided a much more complex and deep answer that someone without the knowledge or experience wouldn't understand. It's crazy this. I now want to go explore the smaller, more efficient models that are designed for particular tasks as that really seems like the way to go.

Loads of installs still use an s-plan setup and manufacturers still provide schematics for this with a bypass for over-run with both valves closed. 🤷‍♂️

Like all things it depends on the numbers and what you actually mean by cooling - are you looking for air conditioning type cooling, or just tempering the excess heat during heat waves? A slab, for example, has a very slow response time, but a cool slab is very good at soaking up direct solar gains due to thermal mass. But also, using slab cooling will increase room humidity and over a longer period can cause discomfort as a result, so sufficient ventilation is essential. Running your heat pump at say 7-8C through fan coils is also much less efficient than running at 16-18C through a slab at which temperatures you'll see efficiencies on a par with low flow temp heating on the same unit. It's all a question of balance and what makes most sense for your architecture and needs.

Stop it both of you! You're going to end up pulling me totally off course now. I'm eyeing up my son's old Lenovo gaming laptop that I just wiped and installed Linux onto - it's almost too tempting....

It really depends on the unit you choose. For example, selecting 2 completely random units - Midea multi-split with a Panasonic multi-split, both on R32: Midea heating output nominal 6.59/ cooling 6.15 kW Panasonic heating output 6.80/ cooling 5.20 kW The Midea lists an SEER of 6.5 A** on cooling and SCOP of 4 A* on heating The Panasonic lists an EER of 4.48 A on cooling and COP of 4.79 A on heating (yes, I know SEER/SCOP is different from EER/COP but that's the published data and the Panasonic is as a kit with 3 room units with multi-room control whereas the Midea is the outdoor unit). These clearly demonstrate a difference between heating and cooling modes - e.g if not on output, then on efficiency. But also something I think is relevant in this kind of decision is the proposed phase out of refrigerants with a GWP of over 150 from 2027 in the EU (the UK will probably follow course). This means that a whole house system using R32 is on a time limited trajectory - and what happens a few years down the line with maintenance?

Of course, heat pumps for heating versus heat pumps for cooling actually require fundamentally different designs, which is partly why one designed primarily for heating won't be as good at cooling as one designed primarily for cooling and vice versa. This is because they have very different operating conditions, different demands on the compressors and also different condenser and evaporator design requirements, not to mention variations in the vapour compression cycle conditions.

Yes, get your heat loss calcs done - but also remember that the heat loss doesn't translate directly to cooling capacity, so you'd need to model that separately. You will be reading MIs but I like Panasonic as all the data is readily available in easily accessible format - https://www.aircon.panasonic.eu/GB_en/ranges/aquarea/fan-coils/

That's awesome!

Oh yes. Finally got it sorted by about 9pm!!!!! It's interesting this and token burn rate. This morning I needed to do some financial modelling and analysis so selected Opus 4.8 for the conversation. 30 min later I looked at my session stats and I'd gone through nearly 80% of my session allocation. Then I select Sonnet 4.6 for another conversation - involves maths but nowhere near as complex and the conversation only burns 3% of session allocation but provides the answers I need. It certainly pays to switch models for different needs.

Bastard! 😉 I'm having a shit day today. Realised it had left a glaring security hole in the Auth model. Decided to fix it, but instead has broken the (expletive deleted)ing app. It fixed part of the problem and then tried to tell me the rest wasn't important until I told it that I could grab an id and post it into the browser in a string and it would expose the entire records for a user, even when not logged it! What was supposed to be a couple of hours at most has ended up taking all bloody day and I'm still trying to explain to it what's going wrong and it still misunderstands me! Thank (expletive deleted) I'm on a dev server.