Whoa......<div><br></div><div>John,Corwyn, and whomever else is on this DOS based list from 1995.</div><div><br><div>Pump the breaks folks.</div><div><br></div><div>First of all, I did not report anything. Ted Cushman did. Furthermore, what I said is being spun and twisted into some sort of malignant half truth.</div>
<div><br></div><div>Its funny to me to walk through life and have people comment
on your work. Funny in a good way. After all, at one point I was hanging out on Shakedown Street trying to get miracle’d. It never happened for mem(although I have seen the Dead a hundred times), and like
the lottery, that was a lesson in knowing that I would always have to work for it (whatever
arbitrary thing "it" could be).</div><div><br></div><div>That work is designing and building high performance,healthy homes. </div><div><br></div><div>So, at least, lets keep things real. Starting with not using words like Dogma. Seriously. I'm meta religious anyway, so we can all give that a rest. PH dogma? WTF?</div>
<div><br></div><div>Now, I can assure you that there are example of PH's in the Northeast that overheat. That is for sure true, and for the sake of being polite I will refrain from pointing them out. They are NOT mine.</div>
<div><br></div><div>My own house even with high SHGC 0.494 windows barely overheats. Once more. It is not even finished. The final design calls for exterior shading in an already heavily shaded area. The house isn't even completely sided yet.The point I was making to Ted was that even with out shading and de-humidification the house is still within PH limits for overheating. Those limits stretch what I consider to be comfortable. Ironic since PH comfort criteria are so stringent and they are totally focused on heating dominated climates, but can be applied both ways.</div>
<div><br></div><div>Yes, the shoulder seasons are rough. especially when counting on deciduous trees for shading. Ext shading is always best whether active or passive with active being superior. It is a retro fit that has gone from 1200 gal/oil yr for DHW and space heat to less than 100gal/oil for DWH only. The mini split is not yet installed either so I have 3/4 of a EnerPHit retro. Flame me, but I dig breaking the house away from the thermal envelope too.</div>
<div><br></div><div><br></div><div>High solar heat gain windows are fine. This isnt a PH thing, its an energy balance thing. If you are creating 20,000Kbtu/yr with tons of south facing glass and SHGC's of .62 , you better god damn well put some shading up. I'll wont ever argue that. I will argue shading on the interior. Once the radiation is in the house its in the house.</div>
<div><br></div><div>The house I designed and built in Knox is performing just fine. Now I just need to get paid for it. It Doesn't overheat. Its comfortable, and so is mine. It will just be better when the shading is up and the mini-split is </div>
<div>installed...........in two years....or whenever.</div><div><br></div><div>A few points</div><div><br></div><div>AHD- is not arbitrary</div><div>SPED- is</div><div>PHPP is fine when used properly. It does account for overheating ,but like ANY model it is just that. A tool for design guidance. Shading is often improperly entered. If you can meet PH in New England with 4" of eps everywhere you model is frigged up. Its not the model but the data enrty that is the key here.</div>
<div>a PH like any super-insulated home should be well designed, that includes balancing loads, with money,with best practice,with research, etc. BALANCE.</div><div>Daylighting is a good thing</div><div><br></div><div><br>
</div><div><br></div><div>John, Thanks for all of your hard work,NESEA talks, and acerbic wit. Maybe you'll invite me to Sommerville some day. I have all kinds of stuff for the hot box. Including our wall assembly.</div>
<div><br></div><div>Corwyn, Thanks for the heads up.</div><div><br></div><div>Everyone else, thanks for a real good time!</div><div><br></div><div>small windows suck</div><div>c</div><div><br></div><div><br></div><div><br>
</div><div><br></div><div><br></div><div><br></div><div><p class="MsoNormal"></p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><br></p></div><div><br clear="all"><font color="#ff6600"><i>Christian Corson</i><br><i>EcoCor Design/Build</i></font><br><a href="http://ecocor.us" target="_blank"><font color="#3333ff">ecocor.us</font></a><br>
<a href="mailto:chris@ecocor.us" target="_blank"><font color="#3333ff">chris@ecocor.us</font></a><br><font color="#ff6600">207 930-5088 </font><br><br>
<br><br><div class="gmail_quote">On Thu, Aug 16, 2012 at 3:17 PM, John Straube <span dir="ltr"><<a href="mailto:jfstraube@gmail.com" target="_blank">jfstraube@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div><font face="Helvetica, Arial,
sans-serif">I dont understand what you are suggesting then
Corwyn if not 1-4. <br>
So you say: 1. dont lower the window SHGC, 2. dont use operable
shades and 3. dont change comfort expectation.<br>
Sounds like that is exactly what Corson has, and he reports, to
no surprise to me, that there is overheating. <br>
<br>
I am arguing against the dogma of "high SHGC windows are
generally a good solution for low energy homes". I beleive they
are generally a bad solution.<br>
Also I am arguing that current models dont properly predict
overheating (even the much lauded PHPP) and that fixating on a
specific space heating target rather than a total primary energy
target can lead one to poor designs than otherwise. <br>
<br>
Your 1. You are making a major assumption that a house with a
SHGC of 0.23 (pretty low, probably too low to get decent
daylight) is a bad house. What tools do you use to support that
and what metric do you use to measure this?<br>
<br>
Your 2. I was proposing 3-5 time reduction in primary energy use
of homes. Who said anything about status quo? Where did I ever
suggest that this was good enough or the right direction?<br>
<br>
Your 3. All energy targets are dependent on occupant choice.
People can choose to run their homes at 74 or 65F for example.
The target is a modeled number using fixed specified inputs to
avoid this. They can however install, gasp, curtains, and
reduce solar gain or they might even plant trees outside. No
target is immune from this. While we as designers have more
control over space heating and cooling than, say hot water or
computers, I do not think there is much evidence to support the
contention that rigorous space heating targets are much easier
to hit than rigorous primary energy targets. In fact, if you
look at the measured space heating usage of the famous
Krongsberg study, which was a PassivHaus development of a row of
townhouses, the actual space heating energy use varied by a
factor of over 5 from lowest space heating usage to highest
space heating usage even with a consistent target of the same
building design built by the same people, eg almost all of this
variation was due to occupancy. This is MORE variation than one
would see for houses built to the same total energy use. <br>
It is not my experience that a heating target gets more
attention from a builder than a total energy target. Having a
target is what seems to matter.<br>
And of course the environment cares only about total energy use
and energy type, not wether that energy is used for heating,
lighting cooking or TV.<br>
<br>
<br>
</font><div class="im">
<div>Dr John Straube, P.Eng. <br>
<a href="http://www.BuildingScience.com" target="_blank">www.BuildingScience.com</a></div></div>
On 12-08-16 2:28 PM, Corwyn wrote:<br>
</div>
<blockquote type="cite">On
8/16/2012 12:17 PM, <a href="mailto:jfstraube1@bell.blackberry.net" target="_blank">jfstraube1@bell.blackberry.net</a> wrote:
<br>
<blockquote type="cite">This whole thread started by mean pointing
out that an obsession with hitting an arbitrary heating number
can result in overheating and high SHGC are part of the problem.
<br>
Without asking people to make many changes in their comfort and
their lifestyle superinsulated homes can make very large
reductions (eg 3 to 5 times less energy that code built) in
their energy use.
<br>
Yes one may be able to get to 5.5 times less energy by asking
people to accept higher temperatures, operate shades or pay 10K
for automatic shades.
<br>
My argument is that there are small benefits to some of these
approaches and high social or economic costs.
<br>
Low SHGC windows, tighter comfort, giving up the arbitrary 15
kwh/m2 heating limit while still accepting the 120 kWh primary
energy number hardly seems like that flawed of a way forward.
<br>
</blockquote>
<br>
I did not say:
<br>
1) People should accept higher temperatures
<br>
2) Operate Shades
<br>
3) Pay 10k for automatic shades
<br>
4) Make ANY changes in their comfort level
<br>
<br>
I am not sure what you are arguing against.
<br>
<br>
My points:
<br>
<br>
1) Low SHGC windows in the house under discussion would *increase*
total energy usage, at the *same* comfort level. I never
recommend compromising comfort levels; I often recommend improving
them.
<br>
<br>
If he replaced his high SGHC windows with ones with s SHGC of 0.23
or lower, the windows would no longer be energy positive, and he
would be better off with a wall instead (which would do nothing to
cause overheating). In general, from a heating/cooling
standpoint, having windows which aren't energy positive is
counter-productive, especially if we expect that people can't be
bothered to open them. (There are, of course, other valid reasons
for having windows.)
<br>
<br>
2) The status quo is not sustainable. Attaining something
sustainable might require a live style realignment. Not attaining
something sustainable will definitely require a new life style.
<br>
<br>
3)(new) I agree that the arbitrary heating limit might not be
ideal. For a builder like Chris Corson, it really isn't, when he
is renovating, and hitting the limit is impossible, he gets as
close as he can. When he is building new, he sees how far *past*
it he can go. For other builders, having that goal actually gets
them to go out of their way to improve heating efficiency; without
the goal they would not have any incentive. For yet others, it
might be a spot where they say 'eh, good enough', when without it,
they would have gone further. My guess would be that most
builders around here fall into category 2, YMMV.
<br>
<br>
A total energy limit does not accomplish quite the same thing, in
that it is so dependent on changeable occupant choices.
<br><div class="im">
<br>
<br>
Thank You Kindly,
<br>
<br>
Corwyn
<br>
Topher Belknap
<br>
<br>
</div></blockquote>
<br>
</div>
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