User Expression for Infiltration Neutral Zone Height

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Hi All

Help please, I am struggling with User Expression that calculates the Neutral Zone Height for high rise infiltration. It's something like:

((Parent("Z")-0)+Local("Height")/2)*-1+(BH/2 - BG)

BH = Building Height
BG = Total of Below Grade FL to FL Height

Also the default expression includes a switch statement. I don't thin I need a switch statement, so how is it formatted?

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Thank you

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Melissa Crowe, LEED AP, BEMP
Senior Mechanical/Energy Engineer

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Melissa Page Crowe's picture
Joined: 2011-09-30
Reputation: 1

Hi Melissa,
Try this expression for NEUTRAL-ZONE-HT:

switch (#SV(#L("INF-METHOD")))
case 0 : unused
case 1 : unused
case 2 : NPL-(#P("Z")+#P("FLOOR-HEIGHT")/2)
case 3 : unused
case 4 : unused
default : unused

Calculate the neutral pressure level for your building and replace "NPL" in the expression with the calculated value.


William Bishop, PE, BEMP, BEAP, CEM, LEED AP
Senior Energy Engineer

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Bill Bishop's picture
Joined: 2012-02-25
Reputation: 7

Bless you ~Bill!

Melissa Crowe, LEED AP, BEMP
508-647-9200 ext. 1225


Melissa Page Crowe's picture
Joined: 2011-09-30
Reputation: 1