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    • CommentAuthorEd Davies
    • CommentTimeMar 3rd 2014
     
    • CommentAuthortargetzero
    • CommentTimeApr 28th 2014 edited
     
    Just released at the conference last week
    PH premium
    PH plus
    PH classic
    PH Energy Conservation building

    figures on the left are your heat demand. figures on the right is the remainder of your primary energy demand (which includes DHW demand, aux electricity and domestic electricity)
    PH Classic 15kwh/m2a heat demand/ 115kwh/m2a is the remainder (120 total including 15 heat demand)

    So take a 200m2 house x 15kwh/m2a = 3000kwh/a
    to produce a kwh using oil or gas costs about 10cents per kwh. so thats 300€ per year for heating (£247/a)
    your DHW demand could be up to 30kwh/m2a.
    • CommentAuthorEd Davies
    • CommentTimeApr 28th 2014
     
    Hello targetzero, welcome to the forum.

    What's the “+RES 60” and “+RES 120” bit?
    • CommentAuthorcullym
    • CommentTimeApr 28th 2014
     
    I think its the amount of energy supplied by Renewable Energy Solutions (RES). All part of the goal to get to nearly zero energy buildings (NZEBs).
    • CommentAuthorEd Davies
    • CommentTimeApr 28th 2014
     
    Hmm, seems NZEB can stand for nearly- or net-zero energy building depending on who's using the term. Luckily there's no room for an argument there ;-)
    •  
      CommentAuthorfostertom
    • CommentTimeApr 29th 2014
     
    All good.

    In essence as far as I can see, these add in consideration of on-site PV/wind/methane generation etc as contribution to electrical/cooking/water heating demand. In 'PH Classic' you were free to do these as an alternative to (minimised) grid supply, i.e. good idea but outside the PH calc.

    Still no integrated consideration, though, of solar gain as contribution to space heating, except for that kind of solar gain that comes in thro windows and (if a bit of storage is desired) falls on heavy floors/walls.

    The latter is a primitive way of harnessing solar gain, which carries with it danger of summer overheating, and therefore must be limited in its scale and therefore in its contribution to space heating. Better ways to do it are quite capable of capturing enough, indeed surplus heat right thro Dec/Jan, without risk of summer overheating.

    Still, neither Classic PH nor the two new grades take this possibility on board - you're free to provide 'back up heating system' in this way, i.e. good idea but outside the PH calc.

    But that 'outside the PH calc' attitude closes the door on the possibility that a building-integrated solar capture/storage delivery design could produce surplus heat right thro Dec/Jan, allowing the stringency of insulation/airtighness standards to be relaxed by a calculated degree - and still fall squarely within high PH targets.
  1.  
    Does no-one else think that this has just added a layer of confusion to the PH brand?

    Part of the appeal of PH for me was that it's either a PH or it isn't (ignoring EnerPHit). Now there are Fifty Shades of Passive it seems to me that there will be even more opportunities for bogus claims to PH achievement...

    I'm reminded of the A+++++ rated appliances etc. Why not just make an A harder to achieve each year/cycle?
    • CommentAuthorEd Davies
    • CommentTimeApr 29th 2014
     
    Agree with both fostertom and Doubting_Thomas, other than that I think that the mistake was to make the appliance grading system open-ended at the wrong end. New more-efficient appliances should be getting G, H, I… ratings. Or, when they realized the problem, they should have gone to A1, A2, … A9…

    But, yes, adding complexity to the rating system doesn't help - you might was well just quote the kWh/(m²·a), etc, figures, e.g., Passive House 15/120, PH 15/90/60, etc.
    •  
      CommentAuthordjh
    • CommentTimeApr 29th 2014
     
    Err, either the explanations are wrong or PHI is guilty of an elementary arithmetic mistake!

    15 + 115 = 130 but the primary energy limit is 120.

    Also I don't understand the statement 'the new “Passive House Plus” label confirms that about as much energy is produced as is consumed' in the press release as compared to 15/90 + RES 60. 60 is not about as much as 90 let alone about as much as 15+90.

    Does anybody have a reference to an actual source document?

    Posted By: fostertomBut that 'outside the PH calc' attitude closes the door on the possibility that a building-integrated solar capture/storage delivery design could produce surplus heat right thro Dec/Jan

    That's quite deliberate I believe. "Fabric first" and all that. Building an 'inadequate' fabric and then adding high-tech (=high embodied energy) renewables energy gear to substitute for the lack of insulation is not what PHI is about, AFAIK. When there's enough as-built evidence of reduced resource usage through an alternative strategy, I expect they may reconsider.

    Posted By: Doubting_ThomasDoes no-one else think that this has just added a layer of confusion to the PH brand?

    Yes, it is quite clearly a signpost labelled 'start of the slippery slope'. I hope the label stuck to it reading 'Danger' is read by enough people.
    •  
      CommentAuthorfostertom
    • CommentTimeApr 30th 2014
     
    Apart from Ed's queries about elementary arithmetic, and leaving aside 'easier' Enerphit, these new categories don't give anything away in terms of stringent targets. So I don't see the slippery slope.
    In fact PHI has nicely drawn a line in the sand and refused those bloomin' Americans who want an 'easier' PH standard 'to suit the American market'.
    • CommentAuthorEd Davies
    • CommentTimeApr 30th 2014
     
    Posted By: fostertomApart from Ed's queries
    Djh's. I missed that. :shamed:

    In fact PHI has nicely drawn a line in the sand and refused those bloomin' Americans who want an 'easier' PH standard 'to suit the American market'.
    Yes, that's good.
    •  
      CommentAuthordjh
    • CommentTimeApr 30th 2014
     
    Posted By: fostertomthese new categories don't give anything away in terms of stringent targets

    Does that mean that you do have a good reference as to what the new targets actually are but aren't telling us, or does it mean that you haven't realized that we don't know what the targets are yet and so don't know why I asked for a reference?

    But apart from facts, back in the land of marketing, the slippery slope is all about brand dilution.
    •  
      CommentAuthorfostertom
    • CommentTimeMay 1st 2014
     
    Posted By: djhor does it mean that you haven't realized that we don't know what the targets are yet
    yes! But I don't get any hint that it's a dilution - why should it?
    • CommentAuthorEd Davies
    • CommentTimeMay 1st 2014
     
    Posted By: fostertomBut I don't get any hint that it's a dilution - why should it?
    Simply having multiple levels is a dilution of the brand - it might not weaken the actual requirements at all but still will make things less clear cut and cause confusion.
    •  
      CommentAuthorfostertom
    • CommentTimeMay 1st 2014
     
    But if these new levels are just add-ons to the otherwise untouched or at least undiluted fabric standard, then why not? They should make it clear that fabric standard is same as ever.
  2.  
    As far as I can see they are just preparing for the new Europe wide building regs that will be implemented in 2020.
    • CommentAuthorDarylP
    • CommentTimeMay 1st 2014
     
    ... except the UK...:devil:
  3.  
    Posted By: fostertomBut if these new levels are just add-ons to the otherwise untouched or at least undiluted fabric standard, then why not? They should make it clear that fabric standard is same as ever.


    Tom,

    The point is, now your average lay customer asks for a PassivHaus and the first response is "which type?" Then they have to sit through an explanation of all the models in the range.

    Although the standard may or may not have changed, the 'menu' of PH types begins to grow in the same way you can't just get a 'coffee' in most coffee shops. It has to be something like 'frothy macchiato with a hint of lemongrass'*

    *can you tell I'm a tea drinker..?!

    Most people I know just want to know how much extra it will cost (a separate argument) - having different types just makes that comparison even harder.
    •  
      CommentAuthorfostertom
    • CommentTimeMay 1st 2014
     
    I hope you tell then that a fully optimised PH will actually cost less?
    • CommentAuthorbarney
    • CommentTimeMay 1st 2014
     
    I'm pretty sure the type of customer asking for a PassiveHaus can get the concept of Classic, Plus and Premium without straining too many brain muscles

    Responding to that in terms of cost should just be a simple "Base Build plus X, Y and Z percent ", firmed up later with an appropriate LZC assessment for renewable options and a review of non heating demand and non regulated electricity consumption.

    Different criteria, but akin to say BREEAM assessments targeting Good, Very Good or Excellent - it's possible to say within a matter of minutes what the cost burden as an addition to base build will be - type of thing that cost consultants live for.

    Going back to the PH renewables, then it doesn't really matter if it's all gained from one technology, or a basket of technologies - cost per kW might vary, but cost per kWh isn't that different

    Regards

    Barney
    • CommentAuthorcullym
    • CommentTimeMay 1st 2014
     
    Trying to figure this out and it dawned on me that the primary energy limit of 120 will include the 2.7 multiplier for "dirty" electricity. If you now replace/offset some of this with PV then primary energy figure drops.

    So taking standard PHPP limit we have 120/2.7 = 44.44 (lets call it 45) is energy used without the multiplier

    So 60kwh/m2/a from PV would more than cover this load. However the primary demand is calculated based on treated floor area, but the RES is based on ground area.

    In my case it would be 116m2 TFA vs 81m2 ground area so

    116 x 45 gives 5220kwh/a

    and

    81 x 60 gives 4860kwh/a

    Not quiet net-zero but getting there. Take the new requirement of 90Kwh/m2/a and factor it down to 90/2.7 = 33.33 (34)

    116 x 34 = 3944kwh/a

    and now we are a net exporter.

    Now I might be way off with this but that's the only way it makes sense to me. My calcs could be off so please check :-)
  4.  
    We've been working on getting Passive Houses to Zero with a few years now.
    They usually use 15kWh/m2.annum for hot water, 20kWh/m2.annum for heating and 20kWh/m2.annum for electricity so 55kWh/m2.annum.
    Sufficient Solar Thermal heating reduces the heating to 1kWh/m2.annum and the hot water figure to 1kWh/m2.annum, so for a 160m2 house a 4kWhP PV array is usually sufficient to get it to zero.

    If I was launching a new Passive House standard I'd add an extra page to the PHPP calculation called Solar Heating and it would show how many m2 of solar is required to get a house to zero.
    The biggest cost in Passive Houses is still all the gadgets and machines, like ducted HRV, Heat pumps, stoves, solar hot water etc,.
    •  
      CommentAuthordjh
    • CommentTimeDec 19th 2014
     
    It's now December and I've just read Benjamin Krick's article in passive house+ magazine and I'm still none the wiser!

    It appears that the definition of passivhaus classic is different to the classic definition of passivhaus, and that seems like a catastrophic marketing mistake to me, so I hope I've misunderstood.

    But the whole scheme appears to be predicated on the definition of something called PER and the definition of PER is noticeable by its absence or by any references to its definition. It does seem though that fundamental to the definition is the concept of an entire electricity generation and distribution system based completely on renewable energy. This begs the question of whether they consider nuclear renewable or not. And they repeat the (IMHO) canard that we must build houses now assuming this to be true because the houses' current boilers will still be in place when the transition is complete. There's nowhere in the world yet that actually meets the starting condition for the definition to be usable. Pigs might fly decades earlier!

    The whole thing still looks like an (IMHO) ill-advised jump into a political minefield; not an area that science-based enterprises are best qualified for.

    Are there any published documents that actually get to the bottom of the PHI proposals, or is it still all a discussion taking part in smoke-filled rooms?
    •  
      CommentAuthorSteamyTea
    • CommentTimeDec 19th 2014
     
    That will be e-smoke filled rooms :devil:
    • CommentAuthorringi
    • CommentTimeDec 19th 2014
     
    Is still don’t understand why a large 3 bed house using x KWH per year is greener than a small 3 bed house that also uses x KWH per year.
    •  
      CommentAuthorSteamyTea
    • CommentTimeDec 20th 2014
     
    It is because we use the wrong measure. I dislike kWh/m^2.
    •  
      CommentAuthordjh
    • CommentTimeDec 20th 2014
     
    Posted By: ringiIs still don’t understand why a large 3 bed house using x KWH per year is greener than a small 3 bed house that also uses x KWH per year.

    I don't think it is. But Passivhaus doesn't measure 'greenness', it just measures the efficiency of the building. That's its appeal to me and is what worries me about the proposed extensions to the standard, since they reach far more into value judgments instead of straight physics.

    It's pretty clear to me that there isn't a single measure of 'greenness' that everybody can agree on, but even if there is, we haven't discovered what it is yet.
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