SimonD

Oh yes, and one of the reasons I avoid heat only installs like the plague. The last one I did, after being sweet talked by the owner, I filled up the system about 10am in the morning but didn't get out of there until 17.30. She was flapping saying it was supposed to be a simple install and I reminded her she hadn't touched the system in 22 years and this was why the water was black when I fushed all the rads. And some of those capped off Tees just collect a nice little air bubble and you've got a nearly unclearable air lock.

It is on here, if not for any other reason than to get @SteamyTea hot under the collar 😁. But on a tangent, I was talking to my son the other day and I was winding him up by using the term phase change where he insists it's state change. I then explained to him that during school I had 2 physics teachers. One was adamant that centrifugal force did not exist and said the only force was centripetal force and the other would repeat that centrifugal force did exist and it was fine to use the term as long as we knew what centripetal force was. Hope this doesn't now cause a 55 page discussion of the reality of force.

Not quite. Curves for radiators and ufh are different - the output factor of each is calculated as to the power of 1.3 for rads and 1 or 1.1 for ufh, so neither are linear and so heat pump curves aren't either. With the curves, you'll general have a default curve and then you adjust this with a heating curve shift. Usually, a heat pump manufacturer will supply a heat curve chart which provides you with the initial basis of your settings - this can be in the manual or just on screen on the main controller. Against this curve, all you need to do is draw from the x and y axes,which tell you the outside air temperature (usually on x-axis) and flow temperature (usually on y-axis), until you meet the curve that matches your heating system design flow temperature and corresponding design outdoor air temperature. Fire the system up and wait at least 24 hours, or if the house is cold and has lots of thermal mass, it could take weeks for the house to thermally balance out. Then you can look at how the system behaves as outdoor temperature fluctuates which will then tell you what adjustments you need to make to the curve and shifts.

That's a good call on both counts. My recommendation is also to have a serious look at the tools out there available - as well as rigs you can knock up with spare timber - that can make your life easier to move and fit materials. One of the things I've noticed is that the trades and builders generally are really bad at thinking things through like this and will scoff at stuff that makes life easier - as a consequence we unconsciously follow those practices. Building on your own takes a very different mentality than a testosterone filled building site with lots of labour available or those who are willing to harm their bodies (I once got laughed at by a builder for putting on some chain saw trousers when I was about to chop down 3 trees). One very small example is atool I bought several years ago was this: https://grabo.com/ It turns lifting plywood, plasterboard, windows, paving slabs, you name it, into a one person job and means you can hold a sheet up to a wall single handedly with putting in a screw with the other. When I first started using it I got giggles from staff in the builders merchants about how I'd just got the vibrator out. Then that turned into how they wished the company would buy a few in for them. I had no idea how much I'd end up using it.

I'm not sure it's agreed that we should extract what we've got. Analogous to the OP, I can't help think about another complex situation we're dealing with in the UK - the NHS - one of the lines of which goes: - Service isn't working - Result = call for more beds/capacity in hospitals - Provide beds/capacity - Find beds filled because patients can't be discharged effectively enough due to internal processes and external capacity (so patients get blamed as bedblockers) - Result is full circle to call for more beds/capacity in the hospital This is the cycle oft shouted from the rooftops from patient groups as well as politicians and the media. The other view, which is mostly ignored from the above is, but very well understood (i.e. they know what needs to change and how to do it but are prevented by those holding the views above): - Model and understand the effects of admitting patients into hospital (including costs) - analyse the data - realise that it is far cheaper, much more effective, and better for patients if they don't have to go into hospital in the first place - costs can actually be reduced to as little as a 10th of the cost of inpatient service - result - a realisation that we have to fundamentally rethink and change how we provide health services, which demands a total mental shift away from what we've been doing for almost 80 years. - therefore resistance, because change is hard and may need additional upfront investment - and what follows is 'oh this is too hard it isn't working immediately. Wards are being closed and we don't have enough beds, so to solve the problem we need more beds' The similarities here are that we know what we need to do, we know how to do it and what is required, we have all the technology in place to do it, but instead we turn back to what we already know, despite all its downsides. Better the devil you know?

That is very good indeed. What internal temperature and what is the floor area, may I ask?

38C is fine with radiators as long as they're sized correctly. My system with all rads ran at 36C at -6 with the whole house nice and toasty. There are really two issues you need to consider and measure. First is the temperatures of all your upstairs radiators and compare this to your ASHP and UFH flow temps. If it's significantly lower, you then know it's a flow issue to the rad circuit and you can tackle this in several ways. If all your rads are about the same temp as your ASHP flow temp, then you know it's more likely an issue with radiator sizing. No need to spend any money right now, just do some simple investigations first.

All you need to do is close the isolation valves on the left hand side of the manifold, connect a drain hose to the return on the right hand side and then connect a supply hose connected to a tap to the flow side on the right hand side. Obviously close all the actuators on circuits that are working. That's what those connectors are for on the right hand side of the manifold.

On your inlet manifold you have you automatic air vent and underneath that you can connect a hose pipe to flush through from there. No need to disconnect your primary flow/return pipes.

We can live in hope. This is one of the reasons China has developed as it has - their leadership develops longer term plans. But that's inherent in Chinese culture where they have a saying that you plant a tree so your ancestors can sit in the shade. We plant a tree, calculate its cash flow and roi and plan on when we can cut it down and burn it in the stove. And from a national security perspective China has to develop its renewable energy infrastructure as it is so dependent upon external supply of fossil fuels. And I think this is our problem with fossil fuels lies. We devour it wastefully as if it had an infinite supply, which we all know it doesn't. The debate surely needs to be more around how we conserve the use of a finite resource such that it supports essential use that cannot be supported through other means. This means a careful and strategic approach to using low grade renewable energy as much as possible where best applied. Unfortunately for many, that does mean a fundamental change to how we view, use and distribute energy. But it doesn't mean that energy necessarily has to be more expensive. The expense of renewables and electricity is down to policy, not the technology as like I've said, we don't count the fossil fuel externalities and if we really did, I think we'd be shocked by the total cost and be shocked by the politics, policy and regulatory costs associated with this. Until the argument/discussion actually includes all these externalities there is no proper comparison.

I think this is akin to the general excuse that regulation gets in the way of projects, but it goes far further than that. It's not necessarily the regulation itself, it's more the interpretation of the policy and regulation and the processes put in place, often with incorrect interpretations of the policy and regulations. It's also that in the UK we typically see these large scale projects as technical/engineering projects rather than larger social ones, which leads to mass hysteria, misunderstanding, resistance and a lack of support. In the UK I think there is a cultural tendency to spend more time and effort trying to avoid or circumvent regulations than just go with them and do it - I see this all the time in construction, from small businesses to large scale developer. But it's also about how the 'experts' in the system can continue to apply out of date or irrelevant models used to understand the projects and on which to base decisions. For example, the use of 25 year discount rates when building infrastructure that lasts and provides positive cash flow for a lot longer than that. Or we have the known issue of optimism bias. A good few years ago I looked at doing another Master's degree and looked at the areas of sustainable energy/engineering and the environment and I looked at both UK and overseas Universities. It struck me then that the perspectives of the UK and USA courses tended to focus more on the issues we're facing as being engineering ones, whereas European Universities took at more balanced view considering the social aspect to a greater extend. This seems to me to reflect the problems we're actually facing as we have all the technology we need already, we don't need to rely on new uninvented technology, we just need to learn how to apply it in a way that people can go along with and also, from a political perspective, we actually need to tell companies how and what they're going to do for us and that's where we need politics to step in rather than step out.

Never an easy solution and always some complexity given the designs of different systems, but generally speaking, we're not very good at using and upgrading existing infrastructure. Just think of all the resources used up to research piping hydrogen through the same network. Given that there has been a huge investment into the gas network laying new pipework, it makes you wonder why there were little thought about how this work could be leveraged for other things. But on infrastructure upgrades generally, back in 2018 I was in Sweden driving some long distances up into the mountains and so many of the roads had trenches dug along the sides of them for their national fibre upgrade project. Sweden of course has its problems, but in comparison we don't seem to have grasped how to do national infrastructure projects, and never spent the time really learning how to do it - even in the days of railway and canal development, it was done privately and piecemeal, and we can't seem to think beyond that it seems.

Makes you wonder why they can't build and deploy a robot to run cable from north to south inside the existing gas network. Or even the oil pipelines that already exist. The overly of gas/electricity looks really rather similar:

This is the bit that's the toughest for me especially when trying to balance everything else that's important in life. With the build, it's not like going home from the office and switching off. One of the things here is that my boys have grown through their teenage years on a building site, but I've spent a lot of time with them away from the build, which at the moment seems to have been the best thing for them. They're living in a warm, dry house, and have their own bedrooms, a bathroom and a functional kitchen, it's just so many other areas of the house still need a lot of work. Deepest winter does seem to be the worst. I approached it with the mentality of - just do one thing, however small it might be. Rather than looking around and seeing how much needs to be done, it's about seeing what little things can I do here or there, even when the weather or light is against me. It's not the solution, but it can very much help. Sometimes I'm surprised by how much gets done as a result and how even just getting some plasterboard put up, can feel so satisfying. But then, sometimes, it is just a pure grind and I see that as just a temporary phase that'll change in a few short days or weeks.

What was the upshot in the end re the over-temp stat on the cylinder?