[Greenbuilding] Passivhaus propaganda
nick pine
nick at early.com
Thu Dec 5 09:04:39 CST 2013
john daglish writes:
> Passivhaus standard with little cost penalty if carefully designed.
With little cost penalty compared to what?
> par ex. Oakmeadow Primary school, Wolverhampton in England built for the
> same budget as a basic thermal regulation UK standard school.
Why not build something that costs less than "a basic thermal regulation UK
standard school" and also needs less than 15 kWh/m^2 of primary heating
energy in a typical meteorological year?
> Note Passivhaus is just an energy standard, any style will work.
Yes, but every actual Passiv building seems to have too much insulation and
airtightness and triple-glazed direct gain windows vs air heaters or
low-mass sunspaces. Is this a prescriptive requirement or a lack of
imagination? Does the PHPP only allow direct gain solar heat? Is it capable
of evaluating other designs, with 2 thermal masses at different
temperatures? Can it even do the equivalent of a single-zone HEED or
Energy-10 simulation?
> Good video technical presentation
> https://www.youtube.com/watch?v=MffKNX5qlLw&playnext=1&list=PLAD94D448BBA00BB9&feature=results_main
Jonathan Hines begins by saying the challenge is to build Passiv "at no
extra cost," then goes on to say that extra Passiv insulation and
airtightness really do cost more, so they simplified the building design to
make the total come out the same (as what?) But the final design still has
about 5 shoeboxes with different roof slopes, vs a simple single shoebox.
Why not use a single simple shoebox for cost and performance comparison? And
why all the triple-glazed direct gain windows and their overhangs and brises
soleils, vs air heaters with natural summertime ventilation instead of
shading, in this "physics-based" standard? If schools perform better without
lots of building thermal mass, why not use a solar heat storage tank with
fan-coils in a lightweight school building? Why daylight, vs fluorescent
lights? Or prismatic diffusing skylights and complex dimming fluorescents, a
la Walmart?
Topher writes:
>There are a number of Passivhaus houses here in Maine. If you would like
>to come see what they are all about, I can arrange for you to be given a
>tour and a complete explanation.
Thanks for the offer. I'll think about that. I get up to see Rich Komp and
Elliot Coleman once in a while, preferably in summertime. When Norman
Saunders and I were at a solar conference at Bates college in February, the
outdoor temperature got above 0, which the locals called "unseasonably
waham."
The Passivehaus standard brings out my anti-Nazi sentiments.
Nick
More information about the Greenbuilding
mailing list