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JohnMo

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Everything posted by JohnMo

  1. JohnMo
    Just did a comparison, the chart above reads slightly lower than a full calculation (500Pa less) 0.9m head, instead of 0.87m.
  2. JohnMo
    Loop length 95 x 90Pa, which s 8550Pa or 0.87m head. Have UFH flow meters open and pressure drop through manifold is small. Plus your pipe, filters and strainer etc.
  3. JohnMo
    Really depends on what the OP wants
  4. JohnMo
    Battery - so only pay 15p max for electric. But air fryer most evenings instead of a big oven (only two of us)
  5. JohnMo
    Do everything a tight fit and foam any small gaps, rather than wholesale foam every piece. I did every joint tight and knocked in place with a piece of wood to spread load and a mallet. Go around edge slowly to insert square not at an angle. Ideal is it needs no foam, but sure that is realistic. Then I taped all the joints.
  6. JohnMo
    So has most other companies if you want any fixed price tariff. But luckily I fixed in September for a year. Hopefully everything will have stabilised or normalised by then.
  7. JohnMo
    Sorry confused - the way you want to operate isn't efficient anyway. So are you fussed about efficiency? You seem willing to spend thousands to get a poor efficiency system anyway. I'm not even convinced you need you need two boilers, but hay ho. I keep looking at this thread and I shouldn't.
  8. JohnMo
    So cosy is cheaper and you get better user experience if you need to speak to anyone etc.
  9. JohnMo
    You can circumvent the system if you want. By simulation of the temperature probe and external control. You need a normal cylinder thermostat - not the probe that is normally used, something with an adjustable hysterisis (e.g. EPH EDBS), and a timer. You then need two resisters 5.6kΏ and 4.1kΏ. A 5.6kΏ resister is equal to 41 degs, you put this across the heat pump terminals where you probe originally connected. The timer/thermostat (zero volt connection, and normally closed) needs to connected in parallel to the 5.6kΏ resistor, and you add a 4.1kΏ resistor in one of the wires from timer. The time/cylinder thermostat then simulate two cylinder temps 41 and 51 degs. You set the ASHP to DHW always on. You use timer and thermostat to achieve what you need. If you cannot wire zero volt switching, you need to add a relay to do that for you.
  10. JohnMo
    Think you may need to install a staircase. If they have done that what have they done you don't see? Run away unless super cheap.
  11. JohnMo
    I added mine after sign off, just incase they said variation. Then did what I felt was ok. Most batteries for houses seem to be a safer rather than less safe battery technology now.
  12. JohnMo
    But if you need to go that level detail, that's ok, but do you really need too? If your that marginal and you need in depth calculations, good chance you are putting an additional pump in anyway. Or someone will add glycol and screw up the theory anyway. Or existing piping has some scale or biofilm which changes roughness and dia and turbulence factors, from poor chemical treatment in the past, and then all bets are off anyway.
  13. JohnMo
    Simple diagram to use, join the dots as demonstrated with the red line
  14. JohnMo
    You only need to take the single most onerous UFH loop, as the UFH run in parallel. Plus the feed and return pipes to manifold from ASHP and manifold.
  15. JohnMo
    We bought loads at the start of COVID, boiler, solar, cylinder, MVHR, all our floor insulation etc. Most came from sales prior to shutting down for lockdown. But it's sensible, if you know what you need, to look out for seasonal sales anyway.
  16. JohnMo
    So if you use 2 zone control, you may need the volumiser with a 7kW heat pump, but if you just run as a single zone I would just take the buffer out the pipe work and slot a couple of spool pieces in. Why - General rule of thumb, and a specific requirement for some heat pumps is 20L per kW of heat output at min ASHP turn down. The 20L is calculated on the smallest zone that can call for heat. If you have a well zoned house (lots of thermostats), leave the buffer as it is.
  17. JohnMo
    I could have asked, but you posted an image that stated 1/2", so would have been a wasted question. But as your using 16mm, all is good. But your loops are really only designed to fit the space, not to match the room heat loss. The loops per room, should be matched to heat loss. Balancing is possible with manipulation of flow rates through each loop, but there is a limited effect, if your circulation pump modulates.
  18. JohnMo
    Never meant to be aggressive.
  19. JohnMo
    All I can say is they are pretty pictures. But unless both spaces are fully open plan, there is zero design work going on. Pipe sizes is questionable. 1/2" pipe isn't really suitable, you should be using 16mm. Your loop length can be around 100m, so the smaller loops can be deleted and incorporated into other loops if you wanted. For info I am doing 7 loops in total for the same heat load.
  20. JohnMo
    Move on to another, one that brings their own tools - will treat their own tools correctly.
  21. JohnMo
    I would suspect for 90% of the year velocity will below min rates anyway. Most heat pumps will modulate circulation pump flow to match heat demand, heat demand will vary and only duty demand rate being required on the coldest days. The rest of the time heat pump should be running close to minimum modulation. Example -my heat pump this morning was circulating at 7L/min, so pretty much well below and min velocity rates.
  22. JohnMo
    Have you cast the concrete yet? Do you have insulation below it? Are your waste pipes there already? Is this a new build or renovation?
  23. JohnMo
    All our trades supplied their own tools, they were responsible for accuracy. If they were after additional costs for tool hire - bye bye, would find a different company. Yes, and the digger and everything else they need. I would expect the basis of the scope to be fully coated and an agreed fixed cost.
  24. JohnMo
    But you may have issues doing DHW - I say this from experience, the heat pump circulation pump runs full speed in most situations. My system drops from 28mm to 22mm for the run to the cylinder - around 10m each way and it needs an additional pump to get adequate flow.
  25. JohnMo
    But it is within flex conduit not directly embedded, - for clarity States similar to this - https://www.multipipe.co.uk/knowledge-base/do-you-install-your-hot-cold-pipes-in-floors/?srsltid=AfmBOopxxCCySW4Q1pdnV0rpxDKf6TCdk71yIPUyWcaBhL6S0K1AMi5D
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