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A_L last won the day on October 12 2017

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  1. A_L

    Rockwool EWI ?

    Just to double-check. The extra insulation is on the cold (out)side of the vapour membrane?
  2. A_L

    Rockwool EWI ?

    Only if the insulation has relatively high vapour resistance and performs as a vapour check, i.e. PIR/PUR/XPS. Possibly EPS. i.e. not rockwool or any fibrous insulation.
  3. O.K., my tuppence worth. Over any five year period oil will only rise at a little more than inflation. Why? Renewables/CO2 Emissions restrictions/EVs will reduce demand and limit price rises. This will leave oil for what it should always have been reserved for, a chemical feedstock (utterly invaluable source of molecules)/lubrication/fertiliser🙄
  4. Knauf Omnifit comes in 90mm, claimed to be suitable for acoustic insulation but lower density than the Rockwools you have posted, so have to double check performance. https://www.knaufinsulation.co.uk/products/earthwool-omnifit-slab
  5. A_L

    Proposed Roof Details

    Not necessarily, 0.15 is better than 0.2, but any serious calculation of U-value must include the timber present in layer three. With at least a 15% timber fraction it will make a significant difference.
  6. @PeteTheSwede If it is t least 30yrears old then it is most likely Urea Formaldehyde foam. It will probably be white and if you squeeze it will crumble as it has become brittle with age. How much this would affect its insulation qualities I do not know. Assuming a lambda value of 0.029W/m.K it gives a U value of 0.44W/m2.K in the build up below.
  7. A_L

    Sunamp installation

    Based on attached pdf the UniQ dPV models appear to do this (fig 1.9 page 7) but it appears to be all the PV output is sent to the Sunamp. Which would be a waste in summer and not enough in winter. Edit - note Sunamp have mislabelled Fig 1.9 as a UniQ ePV. Sunamp pdf2040.pdf
  8. A_L

    Kingspan Insulation equivalents

    How about extruded polystyrene (XPS). You are going to need about 30% more by thickness. https://www.jackon-insulation.co.uk/products/detail/jackodur-plus-300-gefiniert-gl/ There is always mineral wool batts (e.g. prorox SL920) or expanded polystyrene. Both with a lambda of 0.035 so about 70% more by thickness
  9. A_L

    UFH system lots of help required

    The short answer is no, but with much of the house buried in ground it should be possible. The joists of the first storey floor and ceiling are likely to major contributors to air leakage if they penetrate the inner leaf of the cavity wall, taping membrane to them is a laborious and finicky job, with the roof off there may be opportunities to place membrane advantageously. All Kingspan will have to have taped joins. If modifying window reveals, adding insulation to reduce thermal bridging, it should be possible to tape windows to reveals.
  10. A_L

    UFH system lots of help required

    When you mention insulation give the type, it makes a lot of difference to the thermal qualities and as Mike has mentioned other characteristics. You do not mention insulation of the attic ceiling, insulating to U=0.15 is a must. The solid walls, have they any insulation? particularly those which presumably are only partially embedded in the hillside? 50mm of insulation is not enough for the exposed wall, 100mm of insulation of conductivity (k/lambda) less than 0.03 would be better. What direction is the window and single/double/triple glazed? The ground floor should be O.K. with UFH in screed as long as window at least double glazed. As for the attic, if only for occasional bedroom use consider radiators on a separate zone here if you are not using a heat pump for CH. As regards MVHR you need to get total uncontrolled ventilation below about 3m3/m2(external area)/hr to benefit. As explained by Temp above carpet acts as an insulator but you can increase the flow temperature as long as the surface temp does not exceed 27/28°C. It gets cold quickly because there is little storage of heat in a lightweight floor. It does not affect the fuel bill which is determined by heat losses.
  11. Why not just close one valve? This assumes this is not a 'bypass' radiator. Water expands by about 3.5% over the range 20°C/70°C https://www.engineeringtoolbox.com/volumetric-temperature-expansion-d_315.html Edit - forget this 'idea' Or leave enough air in radiator to absorb this without significant pressure increase, assuming this does not affect thermosyphon/circulation within radiator.
  12. I think they are a bit optimistic, even with a 10% timber fraction (38mm@400mm centres) I get 0.13
  13. Not totally familiar with Irish regs but I think they are substantially similar to U.K. On that basis it would be difficult to get an all electric house to have a Dwelling Emission Rate below the Target Emission Rate if no help from a heat pump and insulation levels around building regs values. It should be possible with PH levels of insulation/infiltration however.
  14. A_L

    Hi from Devon

    hello and welcome, I think @pdf27 was thinking along these lines but is now going for knockdown and rebuild, maybe he will be along shortly. https://forum.buildhub.org.uk/topic/4184-in-a-bit-of-a-dilemma/?tab=comments#comment-66331
  15. here is a BBA cert for a very similar Pavatex Diffutherm system bba-certificate-for-nbt-timber-frame-rendered.pdf