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  • in reply to: Insulation around window in 9" brickwall #39241
    Tom Foster
    Participant

      You simply (if only it were simple) have to put a good thickness of insulation between inside air and any part of the external-skin brickwork. How thick the brickwork; where does the window sit in that thickness; therefore how much brickwork 'shows' inboard of the window frame?

      In addition, the frame will be a 'colder' thing, being in full contact with the cold outer skin and also not having any insulation brought across its outside face. So the frame will preferably have best possible PH-grade (or better) insulation within its section.

      Tom Foster
      Participant

        Carry the EWI down to base of foundation in a trench backfilled as a french drain! and minimise or omit the suspended floor insulation. Esp as it looks like you'd get a good deep downstand of insulation hence a good long path-length through soil, of heat passing down through the basement floor, curving out and up to surface. That 'thickness' of soil makes a good insulator. You'd also get a bone-dry basement and it would be part of the heated/habitable volume.

        in reply to: Purge Ventilation in Basements #39218
        Tom Foster
        Participant

          The current re-write of AD F makes a covert necessity of 24/7 Mechanical ventilation or MHRV – the hole-in-wall-type vent rates are eye-watering. In a current change-of-use 1 bed single aspect flat conversion 90,000mm2 'background ventilation; is required – equiv to a 12″ square hole! That's in addition to 'purge' (opening windows) and Kit/Bath 'extract'. Insane. By contrast. MHRV looks convincing – but client's not ready for that yet!

          in reply to: Re: Re: EWI using direct or ventilated rendered finish? #39221
          Tom Foster
          Participant

            How well were the joints between boards corked? Where they simply abutted? Were they sealed with spray foam?

            That's got to be the prime suspect, and 20yrs ago, and now even, there was no understanding (and still today) of that. Mark has highlighted by-pass air movement – even an apparently tight fag-paper joint is relatively a path for the quite powerful convection drive from warm to cold.

            It's classic pattern-staining, familiar even with render on concrete block – the mortar joints, or the open EWI joints, are different temp from the body of the wall, causing differential water content by condensation, hence differential freeze-thaw and solar expand/contract effects, and biological growth (if any), hence colouring.

            If there are open joints between insulation boards then render will be fed into the joint

            More of the same effects – and it's even more the EWI bedding/fixing adhesive. I've seen EWI fitters buttering the ends of EPS blocks with fixative!

            Given the above, resorting to ventilated render is overkill – just attend to the joints in future.

            in reply to: Icynene – alternative to Warmcel? #35835
            Tom Foster
            Participant

              That was 4 months ago …?

              in reply to: EWI insulation shrinkage #38537
              Tom Foster
              Participant

                Yes AFAIK all the artificial insulations pay for themselves multi multi times over. Insulation is the best possible use of oil/hydrocarbons, if you must. What was that podcast?

                … to take embodied energy into consideration. I think it would kill the standard if every item used in the building, and presumably all of the energy of the building process, had to be recorded

                It surely should be an essential part of the building process in general – though we and the world are still practically a long way from taking that on board – otherwise we're knowingly omitting about half the point.

                Paperwork – well that's something that's potential with BIM – on-the-fly embodied energy (in fact whole LCA) totalling as the design/documentation progresses – though again, the BIM cos haven't go round to incorporating that data/facility yet. Strangely, mech eng/product design software is much further aheads on just this, than building's, even though sustainability awareness is much higher in building than in engineering.

                in reply to: Breathable walls without MVHR #39175
                Tom Foster
                Participant

                  Clare or anyone interested if I reply to this rather old thread? It's interesting but full of misconceptions, maybe by the German architect, I think.

                  in reply to: Highest SAP rating? #39182
                  Tom Foster
                  Participant

                    You mean because the energy generated, which is supposed to cancel the heating demand, all comes in the summer/daytime and is largely fed-back into the grid for paltry payment – leaving the winter/night heating demand to be expensively bought from the grid?

                    Yes, come to think, it's as clear as that – which makes that 'trading' aspect of mainstay SAP completely irrelevant to reducing occupants' fuel bills (indeed systematically misleading) – therefore irrelevant also to 'fighting fuel poverty'.

                    I wonder whether the politicians appreciate the latter effect of SAP? Someone needs to publicly trip a politician or two up, when they're boasting about what they're doing to reduce fuel poverty. That might bring a change in this anomaly.

                    in reply to: Highest SAP rating? #39181
                    Tom Foster
                    Participant

                      Is that bad actually? If it allows good SAP for a merely medium-insulation building, it's substituting capital expenditure on hi-tech for same on average-tech insulation and airtightness, for same result as far as carbon, energy demand etc.

                      Yes, having installed energy generation equipment, it's then depriving the nation of that energy product, by 'squandering' it. There might be questions about uncounted eco-footprint resulting from hi-tech, compared to lots of EPS and sticky tape. What else makes the SAP trade-off wrong? It's against 'fabric-first' ideology, but what really is the objection?

                      I sometimes think this kind of thing is OK as long as the energy product is so lo-grade that it can't possibly be seen as tradeable energy commodity – can't be used anywhere except very close to where it's generated (or captured). That is, lo-grade heat. The building itself captures its residual heat demand from the sun. That seems OK as long as it's coming in through windows, but not OK if it's done via solar collectors on the roof.

                      in reply to: Highest SAP rating? #39179
                      Tom Foster
                      Participant

                        Interesting – anything more on this?

                        in reply to: Passivhaus Modelling with Ecotect #39185
                        Tom Foster
                        Participant

                          What a great and painstaking reply from Adesk – wish my chosen Cad provider could or would express themselves so well.

                          in reply to: Re: Re: HRV for comercial kitchen (school) #36962
                          Tom Foster
                          Participant

                            Thanks Kate, also Nick & Coleagues – good stuff.

                            Except, at a glance they don't seem to have taken on board the bit about capture of volatiles causing smell escape. i wonder how their otherwise excellent re-think principles perform smell-wise. I'd love to know what Nick says about that

                            Tom Foster
                            Participant

                              Don't know if this will throw any light, from some genned-up guys on the Bentley forum about running Microstation on Mac; attached

                              in reply to: Re: Re: PHPP sensitivity to air tightness #39063
                              Tom Foster
                              Participant

                                Tom,
                                Please could you provide a link to Fraunhoffer info that you have (assuming that they are online resources.)

                                I did, above, in my post of 24 Nov 2013. That's all there is AFAIK!

                                At a WUFI teach-in where all this was strongly emphasised verbally, it was said that this issue was a major line of development for WUFI/Fraunhofer, to improve on the present guess-a-figure stopgap tool – but since then, on WUFI forum, there seems no interest or even awareness from 'the factory' – indeed even denial of the importance of e.g. testing OSB for air permeance.

                                The latter indifference is not shared by the OSB industry, which luckily is well aware of the need to quality-control the present considerable variability of air permeance from batch to batch.

                                in reply to: Passive irrigation #39146
                                Tom Foster
                                Participant

                                  Going to consult online leaky pipe specialists – any day now! Tell me what you find out?

                                Viewing 15 posts - 1 through 15 (of 330 total)