[Bldg-sim] Impact of Overhangs - Modelling of Fenestration
mike barker
mike at mikebarker.co.za
Wed Feb 10 20:31:44 PST 2010
. 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
BuildingPhysics
Johannesburg, South Africa
mike at mikebarker.co.za
+27 (0) 83 627 7673
skype mike.barker.mba
_____
From: James V Dirkes II, PE [mailto:jvd2pe at tds.net]
Sent: 10 February 2010 04:02 PM
To: 'BldgSim Mailing List'
Subject: Re: [Bldg-sim] Impact of Overhangs
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.
The Building Performance Team
James V. Dirkes II, P.E., LEED AP
1631 Acacia Drive NW
Grand Rapids, MI 49504
616 450 8653
From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Nick Caton
Sent: Tuesday, February 09, 2010 6:13 PM
To: Maria Kordjamshidi; BldgSim Mailing List;
equest-users at lists.onebuilding.org; trace-users at lists.onebuilding.org;
Fareed Syed; John Aulbach
Subject: Re: [Bldg-sim] Impact of Overhangs
Maria, John, Fareed et al:
http://www.buildingscience.com/documents/insights/bsi-007-prioritizing-green
2014it-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
cid:489575314 at 22072009-0ABB
NICK CATON, E.I.T.
PROJECT ENGINEER
25501 west valley parkway
olathe ks 66061
direct 913 344.0036
fax 913 345.0617
Check out our new web-site @ www.smithboucher.com
cid:489575314 at 22072009-0ABB
NICK CATON, E.I.T.
PROJECT ENGINEER
25501 west valley parkway
olathe ks 66061
direct 913 344.0036
fax 913 345.0617
Check out our new web-site @ www.smithboucher.com
From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Maria
Kordjamshidi
Sent: Sunday, February 07, 2010 6:03 AM
To: BldgSim Mailing List; equest-users at lists.onebuilding.org;
trace-users at lists.onebuilding.org; Fareed Syed; John Aulbach
Subject: Re: [Bldg-sim] Impact of Overhangs
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
--- On Sat, 2/6/10, John Aulbach <jra_sac at yahoo.com> wrote:
From: John Aulbach <jra_sac at yahoo.com>
Subject: Re: [Bldg-sim] Impact of Overhangs
To: "Maria Kordjamshidi" <m_kordjamshidi at yahoo.com>, "BldgSim Mailing List"
<bldg-sim at onebuilding.org>, equest-users at lists.onebuilding.org,
trace-users at lists.onebuilding.org, "Fareed Syed" <syedf at progressiveae.com>
Date: Saturday, February 6, 2010, 8:29 PM
Maria:
Excellent information.
Would you please describe what you mean by "free running mode"?
Thank you.
_____
From: Maria Kordjamshidi <m_kordjamshidi at yahoo.com>
To: BldgSim Mailing List <bldg-sim at onebuilding.org>;
equest-users at lists.onebuilding.org; trace-users at lists.onebuilding.org;
Fareed Syed <syedf at progressiveae.com>
Sent: Fri, February 5, 2010 9:47:04 PM
Subject: Re: [Bldg-sim] Impact of Overhangs
Fareed
I have examined the effect of many parameters on the thermal performance of
6 typical houses (single storey and double storey houses) for a moderate
climate of Sydney. a part of my report comes in the following for your
consideration.
"Adding an overhang above all windows improved annual thermal performance of
the typical houses in conditioned mode. However, this was not the case for
the houses in free running mode. The houses presented different patterns of
annual thermal performance in the different modes, responding to increments
in overhang width.
Increases in overhang width of 1m resulted in an average of 4.8% enhancement
in the house's annual thermal performance in conditioned mode. The same
overhang generally caused 3.7% deterioration in annual free running
performance, while a slight improvement was observed in thermal performance
in some cases. The reason for these different results is made clear when
comparing the seasonal performances of each house in two different house
modes.
When all the overhang widths were increased to 1m, the summer performance
improved by an average of 26.6% in conditioned mode. The improvement
decreased to an average of 8% for all houses in free running mode. The
winter performance of the typical houses in this situation deteriorated by
an average of 8.2% in conditioned mode and 11.7% in the free running mode.
Thus the deterioration that was observed in the annual free running
performance of some of the houses in response to the setting of overhang
with a width of 1m for all windows would appear to owe more to deterioration
in their winter performance and less improvement in their summer performance
in free running mode than in conditioned mode."
Hope this help
Maria
--- On Sat, 2/6/10, Fareed Syed <syedf at progressiveae.com> wrote:
From: Fareed Syed <syedf at progressiveae.com>
Subject: [Bldg-sim] Impact of Overhangs
To: "BldgSim Mailing List" <bldg-sim at onebuilding.org>,
equest-users at lists.onebuilding.org, trace-users at lists.onebuilding.org
Date: Saturday, February 6, 2010, 12:22 AM
Folks,
Does anyone have good research data using simulations on the impact of
overhangs and shadings for a typical building?
I am having hard time convincing architects to reduce the glazing. They will
make it a glass building if they are given a chance.
I want to show them that for a 2 or 3 storied building with ton of glazing
and few feet of overhang will not help the cooling/heating loads at all.
I would appreciate your input.
Thanks much.
Fareed Syed EIT, LEEDR AP
Mechanical Engineer
cid:image001.png at 01C9B834.C9D7E7F0
1811 4 Mile Rd NE
Grand Rapids, MI 49525
Phone: 616.361.2664 ext. 3247
Direct: 616.447.3447
Fax: 616.361.1493
<http://us.mc514.mail.yahoo.com/mc/compose?to=syedf@progressiveae.com>
syedf at progressiveae.com
<http://www.progressiveae.com/> www.progressiveae.com
-----Inline Attachment Follows-----
_______________________________________________
Bldg-sim mailing list
http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
To unsubscribe from this mailing list send a blank message to
<http://us.mc514.mail.yahoo.com/mc/compose?to=BLDG-SIM-UNSUBSCRIBE@ONEBUILDI
NG.ORG> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20100211/5fa7e851/attachment-0002.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 2452 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20100211/5fa7e851/attachment-0004.jpeg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 1459 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20100211/5fa7e851/attachment-0005.jpeg>
More information about the Bldg-sim
mailing list