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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Dear Forum,<o:p></o:p></p><p class=MsoNormal>I am soliciting input from you regarding your experience in using full, 8760 hour energy models for energy audits of existing buildings. I have used EnergyPlus for a few of these and am starting to get an opinion about what is important for an existing building energy model. I am convinced that the rules are different than for a new building, but would like to know what your experience has been.<o:p></o:p></p><p class=MsoNormal>My primary interest is the "big picture" factors, not so much the fine details. I have made an outline of factors and considerations below and will appreciate your feedback and comments as you are able!<o:p></o:p></p><p class=MsoNormal>p.s., I suspect that I am not the first to ask this question! If you are aware of past conferences or papers, please point me in the right direction.<o:p></o:p></p><p class=MsoNormal>Energy Audits Which Utilize an Energy Model<o:p></o:p></p><p class=MsoNormal>Factors which imply the need for an energy model<o:p></o:p></p><p class=MsoNormal>• Multi-use (different schedules for portions of the building)<o:p></o:p></p><p class=MsoNormal>• Radically different construction types in different portions of the building<o:p></o:p></p><p class=MsoNormal> o e.g., lightweight construction added to massive construction, high % glazing added to low % glazing<o:p></o:p></p><p class=MsoNormal>• Multiple air handlers of different types<o:p></o:p></p><p class=MsoNormal> o E.g., RTUs for one portion, baseboard heating only for another portion<o:p></o:p></p><p class=MsoNormal>• Anticipation of changing to one of the above<o:p></o:p></p><p class=MsoNormal>• Other???<o:p></o:p></p><p class=MsoNormal>What is the minimum data needed for a defensible / reliable energy model?<o:p></o:p></p><p class=MsoNormal>• Correct total wall area plus window area by elevation?<o:p></o:p></p><p class=MsoNormal> o With low regard for a perfect match to actual geometry<o:p></o:p></p><p class=MsoNormal>• Schedules of operation?<o:p></o:p></p><p class=MsoNormal>• Motor power for fans, pumps?<o:p></o:p></p><p class=MsoNormal>• Air and water flow for fans and pumps?<o:p></o:p></p><p class=MsoNormal>• Special uses?<o:p></o:p></p><p class=MsoNormal> o Pool<o:p></o:p></p><p class=MsoNormal> o Assembly<o:p></o:p></p><p class=MsoNormal> o Specialized equipment such as servers, X-ray<o:p></o:p></p><p class=MsoNormal>• Plug loads?<o:p></o:p></p><p class=MsoNormal>• Outdoor air flow?<o:p></o:p></p><p class=MsoNormal>• Lighting loads in W/sq.f.t? W / zone or room?<o:p></o:p></p><p class=MsoNormal>• Exterior lighting?<o:p></o:p></p><p class=MsoNormal>• Temperature / humidity setpoints?<o:p></o:p></p><p class=MsoNormal>• Air handler control setpoints?<o:p></o:p></p><p class=MsoNormal> o Which ones?<o:p></o:p></p><p class=MsoNormal>• Shading elements?<o:p></o:p></p><p class=MsoNormal>What method should be used for evaluating hard-to-measure data such as actual lighting and plug load use, outdoor air flow, heating / cooling system efficiency at part loads, infiltration, insulation (especially for old buildings with no construction drawings), process power<o:p></o:p></p><p class=MsoNormal>• Trial & error? Using user-imposed restraints?<o:p></o:p></p><p class=MsoNormal>• Benchmark or past project data?<o:p></o:p></p><p class=MsoNormal>• ???<o:p></o:p></p><p class=MsoNormal>How closely must the energy model match past energy use?<o:p></o:p></p><p class=MsoNormal>• Match annual consumption +-10%? >75% R2 month-by-month?<o:p></o:p></p><p class=MsoNormal>• Is actual weather data important? (vs. TMY / “typical”)<o:p></o:p></p><p class=MsoNormal>• ???<o:p></o:p></p><p class=MsoNormal>How carefully must the energy model match define ECMs?<o:p></o:p></p><p class=MsoNormal>• Annual? Peak? Efficiency of new components<o:p></o:p></p><p class=MsoNormal>• Generic or manufacturer-specific performance data?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><img width=336 height=192 id="Picture_x0020_1" src="cid:image003.jpg@01CC9D3B.232E2600" alt="Description: BPT BizCard JVDII Updated"><o:p></o:p></p><p class=MsoNormal><b><span style='font-size:10.0pt'><o:p> </o:p></span></b></p><p class=MsoNormal><span style='font-size:10.0pt'>Tolerance is not agreement. Tolerance is precisely the willingness to restrain from the use of coercion. (and who hasn’t experienced the benefit of respectful, constructive <u>dis</u>agreement?)</span><b><span style='font-size:10.0pt'><o:p></o:p></span></b></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>