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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal>I’m starting to realize that there is a fairly large range of approaches when calculating the PTAC EER value for a baseline model. A simplified approach I’ve always used is to get the baseline EER is to take the total cooling capacity of all the apartments, and then divided that by the total number of units. Then use this average value to calculate EER. I’ve used this approach on a lot of LEED projects and never had a problem. I’m curious if others are calculating in on a unit by unit basis. My approach does take into account that top floor and corner units will probably need bigger and less efficient units. But calculating it on a unit by unit basis could also become very tedious, where a small change in the baseline model could necessitate the re-calculation of every system’s EIR. Also, this all assumes one PTAC unit per apartment. But in a real world design you could easily have one in the living room and a different unit in the bedroom.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I’m just curious what approach people use on this calculation.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Also, I’ve found the controls on the actual PTAC unit a little restrictive so I’ve been using PSZ to model the PTAC systems at times and changing the performance curves.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Steve<o:p></o:p></p></div></body></html>