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<DIV><FONT face="Book Antiqua">Ian,</FONT></DIV>
<DIV><FONT face="Book Antiqua"></FONT> </DIV>
<DIV><FONT face="Book Antiqua">Search the database at Air Infiltration and
Ventilation Center website (aivc.org). You might find something.</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>Best regards,</DIV>
<DIV> </DIV>
<DIV>Gaurav Mehta</DIV>
<DIV> </DIV>
<DIV><FONT face="Book Antiqua"></FONT> </DIV>
<DIV> </DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=Ian.Doebber@arup.com href="mailto:Ian.Doebber@arup.com">Ian
Doebber</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=bldg-sim@gard.com
href="mailto:bldg-sim@gard.com">bldg-sim@gard.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, February 10, 2006
12:15</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [bldg-sim] Insect screens on
restricting flow</DIV>
<DIV><BR></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=022091219-10022006>Does anyone know of any research or published papers
on ventilated facades for extreme climates (~100°F for several months in the
summer and around freezing for several winter months). I am interested
in the application of a ventilated facade in Sacramento California. To
add on that, does anyone know of a ventilated facade building currently
constructed in Sacramento.<BR><BR>Thanks</SPAN></FONT></DIV>
<DIV align=left><FONT face=Arial size=2>Ian Doebber</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>Graduate Mechanical
Engineer</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>Arup</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>901 Market Street Suite 260 San
Francisco CA 94103</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>tel: 415-946-0292</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>fax: 415-957-9096</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>cell: 415-613-4314</FONT></DIV>
<DIV align=left><FONT face=Arial size=2><A
href="mailto:ian.doebber@arup.com">ian.doebber@arup.com</A></FONT></DIV>
<DIV align=left><FONT face=Arial size=2>www.arup.com</FONT></DIV>
<DIV> </DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> bldg-sim@gard.com
[mailto:bldg-sim@gard.com] <B>On Behalf Of </B>Gaurav Mehta<BR><B>Sent:</B>
Thursday, January 12, 2006 5:53 AM<BR><B>To:</B>
bldg-sim@gard.com<BR><B>Subject:</B> [bldg-sim] Insect screens on restricting
flow<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV><FONT face="Book Antiqua">
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">Ian,</FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P><FONT face="Times New Roman">
<DIV dir=ltr><FONT face=Arial size=2>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"></FONT></FONT><FONT
face="Times New Roman"></FONT> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">You raised a very good point. Here are some of the
things that I would like to share and I would appreciate some input
myself:</FONT></P></DIV>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">1. You wrote:</FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">[I'm concerned about insect
screens affecting the buoyancy driven airflow for a double skin
façade.]<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">Dr. Karl Gertis (director of the Fraunhofer Institute
of Building Physics in <st1:place><st1:City>Stuttgart</st1:City>,
<st1:country-region>Germany</st1:country-region></st1:place>) provides a
critical review of double-skin façades in one of his article and cites some
problems in the literature regarding research related to Glass Double Facade
e.g. “<I style="mso-bidi-font-style: normal">window insect screens cannot be
used with natural ventilation because the airflow is too weak to overcome the
pressure loss over the air filter.</I>”<I
style="mso-bidi-font-style: normal"><o:p></o:p></I></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">For more information about the article please go to the
following link:<o:p></o:p></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><A
href="http://gaia.lbl.gov/hpbf/perfor_c.htm">http://gaia.lbl.gov/hpbf/perfor_c.htm</A><o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">2. You wrote:</FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">[I was wondering if anyone new of
some papers that have covered the airflow properties of insect screens or can
give me some information off hand.]<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"></FONT></o:p> </P><o:p>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman"
size=3> Jun Tanimoto,
Jun and Kimura, Ken-ichi (1997), <I
style="mso-bidi-font-style: normal">Simulation study on an air flow window
system with an integrated roll screen</I>, </FONT><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Energy and Buildings
26(3):
317-325.<o:p></o:p></SPAN></P></o:p>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p> </o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman"></FONT> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">There are a few sources that also deal with the effect
of insect screen on airflow but they are specific to <U>wind driven</U>
natural ventilation. <o:p></o:p></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P>
<P class=MsoNormal
style="MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: -0.5in"><FONT
face="Times New Roman"><SPAN
style="mso-tab-count: 1"> </SPAN></FONT><FONT
face="Times New Roman">Swami, M.V. and Chandra, S. (1988),<I
style="mso-bidi-font-style: normal"> Correlations for pressure distribution on
buildings and calculation of natural ventilation airflow</I>, ASHRAE
Transactions, Vol. 94, Part 1, pp 243-266.<o:p></o:p></FONT></P>
<P class=MsoNormal
style="MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: -0.5in"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">This paper provides a procedure for determining
ventilation rates based on the Vickery algorithm (1983), however, assumption
inherent in this procedure is that there is no stack
effect.<o:p></o:p></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal
style="MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: -0.5in"><FONT
face="Times New Roman"><SPAN
style="mso-tab-count: 1">
</SPAN>Givoni, B. (1981), <I style="mso-bidi-font-style: normal">Man, Climate
and Architecture</I>, <st1:State><st1:place>New York</st1:place></st1:State>:
Van Nostrand Reinhold.<o:p></o:p></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="mso-tab-count: 1"><FONT
face="Times New Roman">
</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman">On
pp 304 Section 15.8 Givoni discusses the effect of fly-screens on ventilation.
He quotes van Straaten, the decrease in total airflow, caused by a 16 mesh, 30
gauge wire screen is about 60% and 50% when the wind speeds are respectively
1.5 and 2 mph and only about 25% when the wind speed is 10 mph.</FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt 0.5in"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt 0.5in"><FONT
face="Times New Roman">Straateen, J. F. van, (1967), <I
style="mso-bidi-font-style: normal">Thermal performance of buildings</I>,
Elsevier Publishing Co Ltd<o:p></o:p></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">3. You wrote:</FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">[I'm also wondering how to
incorporate their effects on the flow by use of discharge coefficients and
pressure loss coefficients.]<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P><FONT
face="Times New Roman">
<P class=MsoNormal style="MARGIN: 0in 0in 0pt 0.5in"><FONT
face="Times New Roman">Andersen, Karl T. (1995), <I
style="mso-bidi-font-style: normal">Theoretical considerations on natural
ventilation by thermal buoyancy,</I> ASHRAE Trans. 1995, Vol.101, Part 2,
Paper number SD-95-14-1, 1103-1117</FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">For abstract please visit the following
link:</FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><A
href="http://resourcecenter.ashrae.org/store/ashrae/newstore.cgi?itemid=17248&view=item&categoryid=452&categoryparent=452&page=1&loginid=1357156"><FONT
face="Times New Roman">http://resourcecenter.ashrae.org/store/ashrae/newstore.cgi?itemid=17248&view=item&categoryid=452&categoryparent=452&page=1&loginid=1357156</FONT></A></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman">In
the section ‘coefficients of interest’ the author discusses velocity,
contraction, discharge, and resistance coefficients and may provide insight
into the effect of insect screen on airflow, however, the author does not
directly relate it to the insect screen.</FONT></P></FONT>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman"></FONT> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT
face="Times New Roman">There is a gap in the computation of natural
ventilation research especially in terms of discharge coefficients and
pressure loss coefficients as Ansyley (1999) and Linden (1999) point out that
the computation of natural ventilation lacks experimental data and borrows the
discharge coefficient and flow resistance of openings derived from data
traditionally used for fluid flow in pipes and resistance values traditionally
used in computation of mine ventilation. <SPAN
style="mso-spacerun: yes"> </SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.5in"><FONT
face="Times New Roman">Ansyley R. (1999), <I
style="mso-bidi-font-style: normal">Unresolved Issues in Natural Ventilation
for Thermal </I></FONT><FONT face="Times New Roman"><I
style="mso-bidi-font-style: normal">Comfort, </I>HybVent Forum’99</FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.5in"><o:p><FONT
face="Times New Roman"> </FONT></o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt 0.5in"><FONT
face="Times New Roman"><st1:City><st1:place>Linden</st1:place></st1:City>,
P.F, (1999), <I style="mso-bidi-font-style: normal">Fluid Mechanics of Natural
Ventilation, </I>Annu. Rev. Fluid Mech. 1999. 31:201–38<o:p></o:p></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><I
style="mso-bidi-font-style: normal"><o:p><FONT
face="Times New Roman"> </FONT></o:p></I></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p></o:p> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p></o:p> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p></o:p> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p>Best regards,</o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p></o:p> </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p>Gaurav Mehta</o:p></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p></o:p> </P>
<P class=MsoNormal
style="MARGIN: 0in 0in 0pt"><o:p></o:p> </P></FONT></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=Ian.Doebber@arup.com href="mailto:Ian.Doebber@arup.com">Ian
Doebber</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=bldg-sim@gard.com
href="mailto:bldg-sim@gard.com">bldg-sim@gard.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, January 11, 2006
15:28</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [bldg-sim] Insect screens on
restricting flow</DIV>
<DIV><BR></DIV><!-- Converted from text/rtf format -->
<P><FONT face=Arial size=2>I'm concerned about insect screens affecting the
buoyancy driven airflow for a double skin façade. I was wondering if
anyone new of some papers that have covered the airflow properties of insect
screens or can give me some information off hand. I'm also wondering
how to incorporate their effects on the flow by use of discharge
coefficients and pressure loss coefficients. </FONT></P><BR>
<P><FONT face=Arial size=2>Thanks</FONT> </P>
<P><FONT face=Arial size=2>Ian Doebber</FONT> <BR><FONT face=Arial
size=2>Graduate Mechanical Engineer</FONT> <BR><FONT face=Arial
size=2>Arup</FONT> <BR><FONT face=Arial size=2>901 Market Street Suite 260
San Francisco CA 94103</FONT> <BR><FONT face=Arial size=2>tel:
415-946-0292</FONT> <BR><FONT face=Arial size=2>fax: 415-957-9096</FONT>
<BR><FONT face=Arial size=2>cell: 415-613-4314</FONT> <BR><A
href="mailto:ian.doebber@arup.com"><U><FONT face=Arial color=#0000ff
size=2>ian.doebber@arup.com</FONT></U></A> <BR><A
href="file://www.arup.com"><U><FONT face=Arial color=#0000ff
size=2>www.arup.com</FONT></U></A> </P><PRE>____________________________________________________________
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