[Greenbuilding] Aggressively Passive: Building Homes to to the Passive House Standard

[John Straube]

Yes, I think this is part of the problem.  I have the PHPP 2007, having paid my money several years ago and have used it
As I have said, it is a very good spreadsheet.
There are many programs like PHPP that have been developed and calibrated with houses in North America too (and Sweden, UK, etc).
The CEPHEUS reports show that it is about is accurate (or inaccurate, as the results are +/-50%) as other programs.  No better, sometimes a little worse than many other programs. We regularily use hourly programs for the design of all our low-energy houses since they are easy to use and fairly accurate.
I am well aware of the requirements of PH.  

The questions are "Why"? Where is the scientific justification for 10W/m2?  And the 4 C asymmetry? Why?
I understand these are edicts from Darmstadt, but I would like to understand the science so that I can explain and modify the results for other climates.


On 2011-01-27, at 1:02 PM, John Daglish wrote:

> Bonjour jfstraube,
> 
> The PassivOn project has been calibrated for some European climates.
> www.passive-on.org
> 
> But using the PHPP planning package (15 or so linked excel
> spreadsheets) with your monthly climate data you can modulate the u
> values, etc. which does a fair stab at it for a static /steady state
> calculation provided
> you take into account the minimum requirements eg 10W/m2 max heat/cool load,
> asymetric radiant temperature différences less than 4C, etc.
> The PHPP package is correlated against constructed project operational
> data * and
> the PHI Passiv Haus Institutes inhouse dynamic (hourly) calculation
> program.
> 
> * eg. Cephus project measured results
> http://www.passivehouse.com/07_eng/news/CEPHEUS_final_long.pdf