<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=utf-8">
<META content="MSHTML 6.00.2900.3199" name=GENERATOR></HEAD>
<BODY style="MARGIN: 4px 4px 1px; FONT: 10pt Tahoma">
<DIV>I agree that the App. G fan power and PLR curves are only for Baseline fans.</DIV>
<DIV> </DIV>
<DIV>A few other comments related to your ?s:</DIV>
<DIV> </DIV>
<DIV>1. Table G3.1, No. 1(b) says that "all *conditioned* spaces in the proposed design shall be simulated as being both heated and cooled even if no heating or cooling system is to be installed..." [emphasis mine]. I wonder if what you're describing would be considered a "semi-heated" area instead of "conditioned." If it is semi-heated, C5.2 gives the guidelines that both baseline and proposed should be heated only and have 50F setpoints. Of course, the PRM doesn't specify App. C.... This is most likely intended for garages, warehouses, etc., though. If your building has office spaces where people will want to maintain more comfortable temperatures, then I would say to call it "conditioned" and model it as heated and cooled as G3.1, 1(b) says. Just something to think about.</DIV>
<DIV> </DIV>
<DIV>2. As far as how many systems to model, here is what I think. Addendum U to G3.1.1 says that for systems 1-4, each thermal block will have its own system. For systems 5-8, each floor should have its own system. The main exception would be spaces that have significantly different internal gains or schedules - they are supposed to be modeled separately as either system 3 or 4 (depending on heat source). So unless you have a bunch of these different spaces (like an auditorium, pool, cafeteria, etc.), your baseline should include only one system per thermal zone for 1-4 or per floor for 5-8. For your proposed model, it should include the exact same systems as shown in the proposed design drawings.</DIV>
<DIV> </DIV>
<DIV>3. You might want to use Addendum ac for the latest way (that I know of) to calculate baseline fan power. If this is for a LEED project, the USGBC issued something back in April saying it was OK to use addenda to App. G.</DIV>
<DIV> </DIV>
<DIV>4. Table G3.1, No. 4, Exception (a) says that if you are only including heating or cooling to comply with App. G, then you can let the fans cycle on/off during occupied hours during this mode (in your case, during cooling mode). This will affect your fan energy.</DIV>
<DIV> </DIV>
<DIV>If anyone has any comments or updates to what I wrote above, let me know!</DIV>
<DIV> </DIV>
<DIV>Kristin</DIV>
<DIV> </DIV>
<DIV>
<DIV><BR>***************************************************************</DIV>
<DIV>Kristin M. Field, EI</DIV>
<DIV>Energy Analysis Group</DIV>
<DIV>Architectural Energy Corporation</DIV>
<DIV>2540 Frontier Ave., Suite 201</DIV>
<DIV>Boulder, CO 80301</DIV>
<DIV>303.444.4149</DIV>
<DIV> </DIV>
<DIV> </DIV><BR><BR>>>> "Zarske, Jim" <jzarske@nexant.com> 11/15/2007 3:38 PM >>><BR>I've interpreted Appendix G that they fan sizing is for the baseline<BR>building only; use actual fan sizes for the proposed building.<BR><BR>The fan sizing run should only apply to the 8 predefined system options<BR>in Appendix G for your building type. So, if you're taking one of these<BR>defined systems that applies to your building and modeling it on each of<BR>your proposed spaces, you would have to do a sizing run for each system.<BR>The sizing run should be at the HVAC system level.<BR><BR>-----Original Message-----<BR>From: BLDG-SIM@gard.com [mailto:BLDG-SIM@gard.com] On Behalf Of Karen<BR>Walkerman<BR>Sent: Thursday, November 15, 2007 2:57 PM<BR>To: BLDG-SIM@gard.com<BR>Subject: [BLDG-SIM] Appendix G Supply Fan Power<BR><BR>Hi All,<BR><BR>Question about ASHRAE 90.1 Appendix G3.1.2.9 (calculation for fan energy<BR>use):<BR><BR>does this apply only to the baseline model? I assume that actual fan<BR>power should be used for the proposed design, but ASHRAE doesn't state<BR>it explicitly.<BR><BR>Also, should fan power use be calculated for each space served by an<BR>independent system, or for the whole building?<BR><BR>I am modeling a building that is supplied with baseboard heat, and no<BR>cooling. There are a number of small offices that have independent<BR>thermostats for heating. As per LEED requirements, these spaces must be<BR>modeled as having mechanical cooling. Some of the spaces only require<BR>2-300 cfm of supply air. If I do the calculation for each space, I end<BR>up with 8 watts/cfm!!! (can't be right)<BR><BR>Thanks for any input,<BR><BR>~Karen~<BR><BR>--<BR>Karen Walkerman<BR>Second Law Consulting<BR>kwalkerman@gmail.com<BR><BR>======================================================<BR>You received this e-mail because you are subscribed to the<BR>BLDG-SIM@GARD.COM mailing list. To unsubscribe from this mailing list<BR>send a blank message to BLDG-SIM-UNSUBSCRIBE@GARD.COM<BR><BR><BR><BR>=====================================================You received this e-mail because you are subscribed<BR>to the BLDG-SIM@GARD.COM mailing list. To unsubscribe<BR>from this mailing list send a blank message to<BR>BLDG-SIM-UNSUBSCRIBE@GARD.COM<BR><BR></DIV><PRE>
===========================
You received this e-mail because you are subscribed
to the BLDG-SIM@GARD.COM mailing list. To unsubscribe
from this mailing list send a blank message to
BLDG-SIM-UNSUBSCRIBE@GARD.COM
</PRE></BODY></HTML>