[Bldg-sim] Impact of Overhangs

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Maria:

Excellent information.

Would you please describe what you mean by "free running mode"?

Thank you.

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Maria, John, Fareed et al:

http://www.buildingscience.com/documents/insights/bsi-007-prioritizing-green2014it-s-the-energy-stupid

These guys have a good bit of interesting reading ? recommend bookmarking this link if you also have the capacity to be entertained/chuckling with this kind of thing =). As I read this call for reason/logic, I recalled this article they put out (linked above) that pretty well spells out the logic to a layman behind ?less glass > better glass.?

That article above is probably worth your time and your architects? to read over to get the point across. If/when they want you to drive it home, I?d suggest simply building your site-specific 2/3 story building model and running it once with something like 30% glazing (with a picture so they can visually see that?s a lot of glass), and again with 100% storefront glass box and let their eyes bug at the energy cost differences.

Impact of overhangs for a ?typical building? is something you?ll have trouble finding an answer to, as it?s obviously quite site and orientation specific. Again I?d suggest running two models and observing the differences with/without the overhangs in question. eQuest is one of many tools appropriate to the task-at-hand.

NICK CATON, E.I.T.

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John
?
Free running: refers to the state of a building that is naturally ventilated and does not use any mechanical equipment to maintain or improve its indoor thermal condition.
?
Maria

Maria Kordjamshidi's picture
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Maria, John, Fareed et al:

http://www.buildingscience.com/documents/insights/bsi-007-prioritizing-green2014it-s-the-energy-stupid

These guys have a good bit of interesting reading ? recommend bookmarking this link if you also have the capacity to be entertained/chuckling with this kind of thing =). As I read this call for reason/logic, I recalled this article they put out (linked above) that pretty well spells out the logic to a layman behind ?less glass > better glass.?

That article above is probably worth your time and your architects? to read over to get the point across. If/when they want you to drive it home, I?d suggest simply building your site-specific 2/3 story building model and running it once with something like 30% glazing (with a picture so they can visually see that?s a lot of glass), and again with 100% storefront glass box and let their eyes bug at the energy cost differences.

Impact of overhangs for a ?typical building? is something you?ll have trouble finding an answer to, as it?s obviously quite site and orientation specific. Again I?d suggest running two models and observing the differences with/without the overhangs in question. eQuest is one of many tools appropriate to the task-at-hand.

NICK CATON, E.I.T.

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This article (or a version of it) appeared in the ASHRAE Journal a few months back and lit a firestorm of letters to the Editor. I think the author is on target and also excellent at getting his readers to think in greater depth about some of the common design issues of our day.

James V. Dirkes II, P.E., LEED AP

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. and if you are an Architect and modeling is new to you, you may want to
take a look at COMFEN 3 from the famous LBNL -
http://windows.lbl.gov/software/comfen/comfen.html

It's free and will allow you to test the 20% vs 30% vs 40% WWR debate for
your particular climate, including all sorts of shading, building
orientation, and glass types too.

There is another package called EFEN that does much the same for whole
buildings - http://www.designbuildersoftware.com/efen.php

Try them - it will take you 2 hours to get your first model out and you will
probably find this approach better than the usual rules-of-thumb :-)

Thanks,

Mike Barker, LEED AP


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Dear Maria,

The test cells in Launceston and the test houses in Hobart were operating in
free running mode.

Mark Dewsbury

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