MikeSharp01

I did the calcs with 28mm because ours is 28mm so was interested to know the figures and given the size and relative difference I figured it will scale OK.

Its not wasting our time, many of us want to understand this better, and its adding to the community of knowledge that pretty soon everybody using the LLMs will have access to as well. I Just asked Chat GPT and Copilot to run the calcs on this query: "I have a flow rate of 1000l/Hr in my heating system and 28mm copper pipe work (external Diameter) I need to realign the pipe work using either 2 90degree bends or a single flexible pipe. Can you give me an analysis of both options in terms of pressure drop please." From Co-Pilot I got: Comparison Summary 🧩 Design Implications The flexible bend offers ~80% lower pressure drop, which is beneficial for pump efficiency and flow stability. It also reduces turbulence, which can help with noise and long-term wear. If space and installation constraints allow, the flexible pipe is clearly the hydraulically superior option. From Chat GPT I got: Calculated pressure losses — summary All values shown in Pascals (Pa); 1 Pa = 0.01 mbar. Two 90° long-radius elbows + 0.5 m copper elbow minor losses: 2K(ρv2/2)=2×0.3×(ρv2/2)2K(\rho v^2/2)=2×0.3×(ρv^2/2)2K(ρv2/2)=2×0.3×(ρv2/2) ≈ 80.7 Pa friction (0.5 m): ≈ 61.3 Pa Total ≈ 142.0 Pa (≈ 1.42 mbar) Two 90° short-radius elbows + 0.5 m copper elbow losses ≈ 242.2 Pa friction (0.5 m) ≈ 61.3 Pa Total ≈ 303.5 Pa (≈ 3.04 mbar) Two very sharp 90° bends + 0.5 m copper elbow losses ≈ 403.6 Pa friction (0.5 m) ≈ 61.3 Pa Total ≈ 464.9 Pa (≈ 4.65 mbar) Single flexible connector, 0.5 m long (same ID = 26 mm) friction (0.5 m) ≈ 63.2 Pa (plus small end fittings—typically tens of Pa if any) Total ≈ 63.2 Pa (≈ 0.63 mbar) Recommendations If your flex connector has the same internal bore as the copper and is reasonably short (≈0.5 m), go flexible for slightly lower hydraulic loss and easier alignment. If the flex has smaller ID or will be long, use long-radius elbows or re-route with larger-bore flex — avoid small-bore flex for flow-critical runs. If you want exact numbers for your exact components, tell me: actual pipe wall thickness or measured ID of your 28 mm tube, the internal diameter and length of the flex you’re considering, and whether your elbows are long-radius or short/standard. So my thoughts are: They are both within a few pascals. They do make assumptions and of course they know nothing about how tortious the flexi will be bent but it looks like, assuming they have both not hallucinated, the flexi option comes with a lower loss BUT if you look at the difference in head loss its only around 25mm (0.025m) between them so not that significant in your situation.

In theory yes, but might a couple of large diameter flexis not make all the transitions smoothly and so remove the need for the 90 deg angles everywhere.

Two things we, my other half and I, learned from doing it really. First thing is to get the membrane which must be the reinforced type with the embedded net, as tight as you can so you limit the sagging you get when you pump in the cellulose. Secondly use the widest sheet of membrane you can get. We used the 4m wide stuff from intellio. Many fewer tape joints. Our fixing was to clamp the membrane between the rafter and a counter batten running along the rafter with screws going through pre- drilled holes in the counter batten. Screwing ensures you can get it really tightly clamped and the holes make sure you get no jacking so you get an air tight seal around the screw hole, which if you think about it is actually filled by the screw anyway. Once the cellulose was in and we had done the seals round roof lights and windows we got a 0.2 score on the passive house air test so something must be about right.

+1 to most of that: We had power floated the garden room and it worked well we have an acceptable surface in there BUT the main house was not because: 1. It was very hot over 30OC 2. Much bigger roughly 3 times the area of the garden room. 3. Not enough people, we had 5 working all the time, but only two of us had the experience on the garden room. 4. We didn't have a long enough floating bar - our hire people let us down on that, the long bar was not available, so we needed more passes which took more time than we had given the drying rate. In the end about 70% of it was more than acceptable but 100% is the only answer unless you want level changes in your floor areas. It was a disappointing day but we knew the risks and accounted for failure in the plans - eg levels. As an idea of the cost of failure the flooring cost for us is about £18K more than it would have been had we succeeded which might put the £32K somewhat into perspective for you. All in all my advice is not to try it yourself, look at the balance of costs and get a few more quotes.

Welcome to THE forum for people like us.

You do need to measure the floor temperatures, get a cheap IR gun. (the one below is about £50 from Screwfix but you can get a lot cheaper, 1/3rd the price, versions from amazon). Have you replaced the floor coverings since the Oil boiler? If you have then the flow rate thing will need to be tackled see posts above but also you need to watch out that you do not overheat the floor. You can also work out the TOG value of the laminate, which will give you an idea, along with a bit more working out, just how much to increase the flow rate and / or the delta temperatures across the system.

Keep on keeping on and all will be well, all the best.

Which model is that? We are looking to install the Cool Energy CE-iH6+ which delivers 1.85-6kW @ 7 degrees and at -3 degrees 1.2-3.9kW which is about bang on for us where we need 1.139kW according to their calcs.

I think of PFC as Power Factor Correction assuming this the possible reasons are all over the place but as @Michael_S says could be a mains glitch that took it out of range. If so it probably will not recurr but if it does you will need to dig deeper loose wire or something that causes the motor a problem which I suppose a high speed gust of wind right up its axis might well do.

Interesting! You need to pack it round underneath with as much PU as you can, get some wood along the top of the beam + down the side of the flange at the top and foam fill all the voids down the sides. The fixing of the ridge tiles can still be done with cement as you would be fixing to wood.

Welcome to THE forum for people like us. Very sorry to hear your story and here to offer help and support, probably best to start a new thread to unpack it all and we can start helping with advice and confidence building.

I guess he means making sure the heat pump (HP) can also cope with making domestic hot water (DHW). If your house heating needs 5kW then a 5kW heat pump won't be big enough, on the worst days, if the HP also has to make DHW because all its output will be needed for heating. The important thing is that this may only be a problem on the worst (coldest outside) days of the year when you could either accept a slight drop in heating while the HP is making the DHW or use the Immersion heater to make the DHW or get the next size up HP, or much bigger if you need loads of DHW see other threads here, to let it cope with the DHW.

Our concern was the suitable distance! We were worried that if we did not get close to the source of any particle laden steam / air it would allow said air to get dispersed and so deposit its load around the place and not into the grease sock - hence we went for directly above the hob. We have yet to commission it all all so won't find out until then

I thought about this approach but decided I wanted the grease in replaceable filter in the MVHR and not more thinly spread everywhere so we have an MVHR extract vent with a grease sock directly above the hob.

That is correct, you need to account for your costs.

Another approach might be to find an installer offering the MCS umbrella scheme. Here the process is that they do the design work, you purchase the bits and install them and they comeback commission it all. I our case they are charging a basically fixed fee, might vary if they have to do more work at the commissioning phase. They apply for the grant take there cut and hand you the rest.

That's an interesting link looks like the blog at the top is about on the money!

I did it with RPi Pico W talking to my Growatt. I send the data out as mqtt messages which I then read anywhere and log the data on a remote pc direct to mysql, the Pico is not great for logging.

Insulation weights very little and anyway the holding capacity of plasterboard screws is limited by the plasterboard not the screws because the screws just pull through it. 40mm will be fine just make sure you have plenty of screws.

It struck me that it may have been used to try and straighten the ridge - pull everything along a common line or at least pull out the larger bends =- which may only have been a few mm. It is also possible that it was used to keep everything together while the roof was put on, so when the structure was it it's weakest, and the intention was to remove it but never done.

YES Claude can't, even Git copilot won't do it with you asking it to / confirming. Not used Claude code so cannot say for sure, but a colleague does and I think it only does it with automated workflows and associated commands not because this code looks like worth a push.

Yes.

Ask Claude of course.

Welcome to the forum -p sounds like a fun but very challenging project. If you follow the work on here done by @nod he bought two plots. I guess there are Community Infrastructure Levy (CIL) issues that you should look at with great care before you break ground!!!!