Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)

Categories



Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.
Buy individually or both books together. Delivery is free!


powered by Surfing Waves




Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
 Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.




Building Regulations and Standards: Passivhaus “primary energy demand”

Bottom of Page

1 to 8 of 8

  1.  
    • CommentAuthorEd Davies
    • CommentTimeJun 29th 2012
     
    The Passivhaus standard refers to primary energy demand being less than 120 kWh/(m²·a).

    Do they actually mean “primary energy demand” in the sense it's usually used in economics and so on: the energy contained in the originating fossil fuel or whatever so if you use 4 kWh of electricity generated by a plant which is 40% efficient that counts as 10 kWh? Or do they mean energy delivered to the house via the various pipes and wires in the street?
    •  
      CommentAuthorDamonHD
    • CommentTimeJun 29th 2012
     
    I hope they mean the former as anything else is mixing apples with oranges, ie 1kWh of electricity is not the same in practical/CO2/money/other terms as 1kWh of gas.

    Rgds

    Damon
    • CommentAuthortony
    • CommentTimeJun 29th 2012
     
    It wont be long until there is no more gas oil to use compared to the life of a building.
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 30th 2012
     
    Posted By: tonyIt wont be long until there is no more gas oil to use compared to the life of a building.

    Plenty of natural gas to see all of us out, and coal, probably oil as well, though that isn't the point.

    Posted By: Ed Davieshope they mean the former

    Yes, this does cause confusion as electricity generated from gas and then used to heat a home via a heat pump as opposed to a restive heater gives very different numbers, as does burning coal in the grate compared to in a large power station to make electricity to run a telly.

    Should we distinguished kWh (or MJs) by using kWh(p) for primary energy and kWh(d) for domestic energy use in the home instead of just kWh? Or just let the reader decide.
    •  
      CommentAuthordjh
    • CommentTimeJun 30th 2012
     
    Posted By: Ed DaviesDo they actually mean “primary energy demand” in the sense it's usually used in economics and so on: the energy contained in the originating fossil fuel or whatever so if you use 4 kWh of electricity generated by a plant which is 40% efficient that counts as 10 kWh? Or do they mean energy delivered to the house via the various pipes and wires in the street?

    Yes, they follow the usual definition. They specify particular aspects of the calculation so as to get comparable figures between different houses and to minimise cheating. There's pages of stuff in the PHPP manual. The best web expalanation I can turn up in a few minutes is:

    http://www.sphc.co.uk/electricity-generation-consumption-passivhaus
    • CommentAuthorEd Davies
    • CommentTimeJun 30th 2012
     
    Thanks, djh. Good reference.

    For those figures (2.7 for electricity and 1.1 for gas), do you know if they're the same everywhere or whether they've just quoted Scottish figures? It seems to me that they could reasonably vary between countries - e.g., in a nuclear country like France the electricity figure could be a lot lower, perhaps even less than one.

    (By the way, ST, it was actually Damon who said “hope they mean the former” but it's not much of a misquote, I'd hope so too.)
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 30th 2012
     
    Strange how the quote thingy glitched, yes I hope so too.
    •  
      CommentAuthordjh
    • CommentTimeJul 1st 2012
     
    Posted By: Ed DaviesFor those figures (2.7 for electricity and 1.1 for gas), do you know if they're the same everywhere or whether they've just quoted Scottish figures?

    I believe the 2.7 is a figure used for the whole of Europe based on a DIN standard, but I've seen other things that talk about national agreements. The 2011 revision of PHPP has the 2.7 adjusted to 2.6. You'd need to talk to a certifier to get a full understanding, I think.

    (IMHO, PHI could be a lot clearer and more open about details like this - it ought to be trivial to go to their website to discover the answer to a question like this)

1 to 8 of 8

  1.  
Add your comments

    Username Password
  • Format comments as
 
Back to Discussions Top of Page
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press