<div dir="ltr">every orthodoxy, including passive house, exposes its fallacies and contradictions when pushed to the limit. I'm tripping over one of them on a current project that is precertified by PHIUS. Now, in mid construction, the owners wish to turn what was planned as an unheated 3 season space into heated space. In itself, this is neither unreasonable nor unusual. But the masonry piers are already in place, and furthermore, this space is small to begin with, and shoved up against two setbacks, so there is no reasonable way to develop the 16" wall thickness the rest of the house is built with. Connecting it to a meticulously designed mechanical system would compromise performance elsewhere in the house.<br>
<br>So the certification is probably blown. What's left is to sort out what levels of insulation and fenestration make the most sense, and what sort of independent mechanical system to use. <div><br></div><div>But even so, there is one important result from this exercise: that is a better understanding of heat losses and gains, and the ability to make a reasonable prediction of the energy performance of this house. This is only possible with a systematic approach. <br>
<br>Whether other systems do it more accurately, or faster, or with fewer calories than PHPP is a somewhat different question. In fact, PHPP is fundamentally obsolete, superceded by WUFI-Passive, which not only analyzes heat gain and loss on an hourly basis, but also charts the accumulation of water vapor in envelop assemblies--and does this over the course of many years.<br>
<br>It goes to ultimate objectives. If it is accepted that our society should be carbon neutral by 2030, then we must use a systematic approach to get there. <br><br>AA </div></div><div class="gmail_extra"><br><br><div class="gmail_quote">
On Thu, Dec 5, 2013 at 10:04 AM, nick pine <span dir="ltr"><<a href="mailto:nick@early.com" target="_blank">nick@early.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
john daglish writes:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Passivhaus standard with little cost penalty if carefully designed.<br>
</blockquote>
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With little cost penalty compared to what?<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
par ex. Oakmeadow Primary school, Wolverhampton in England built for the same budget as a basic thermal regulation UK standard school.<br>
</blockquote>
<br>
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?<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Note Passivhaus is just an energy standard, any style will work.<br>
</blockquote>
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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?<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Good video technical presentation<br>
<a href="https://www.youtube.com/watch?v=MffKNX5qlLw&playnext=1&list=PLAD94D448BBA00BB9&feature=results_main" target="_blank">https://www.youtube.com/watch?<u></u>v=MffKNX5qlLw&playnext=1&list=<u></u>PLAD94D448BBA00BB9&feature=<u></u>results_main</a><br>
</blockquote>
<br>
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?<div class="im">
<br>
<br>
Topher writes:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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.<br>
</blockquote>
<br></div>
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."<br>
<br>
The Passivehaus standard brings out my anti-Nazi sentiments.<span class="HOEnZb"><font color="#888888"><br>
<br>
Nick <br></font></span><div class="HOEnZb"><div class="h5">
<br>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><font><font><span style="color:rgb(102,0,0)">Alan Abrams</span></font><b style="color:rgb(102,0,0)"><br></b><i><span style="color:rgb(102,102,102)">certified professional building designer, AIBD<br>
certified passive house consultant, PHIUS</span></i></font><div><i><span style="color:rgb(102,102,102)">certified passive house builder, PHIUS</span></i><font><span style="color:rgb(102,0,0)"><font color="#666666"><i><br>
</i></font></span><font><span style="color:rgb(102,0,0)">Abrams Design Build LLC</span></font><font size="4"><br style="color:rgb(102,0,0)"><font><i style="color:rgb(102,0,0)">sustainable design for <font>intentional</font> living</i></font></font></font><font style="color:rgb(102,102,102)" size="1"><font><br>
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