User Expression for Infiltration Neutral Zone Height

3 posts / 0 new
Last post

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)

Where:
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?

[cid:image002.png at 01D5FC44.8B3B4270]
Thank you

[cid:image003.png at 01D5FC44.8B3B4270]
Melissa Crowe, LEED AP, BEMP
Senior Mechanical/Energy Engineer

[cid:image001.jpg at 01D5FC3E.6F425E10]

Boston Office
161 Worcester Road
Suite 305
Framingham, MA 01701
508-647-9200 ext. 1225
www.cmta.com
Follow us on Facebook, Twitter and LinkedIn

We've moved! Our new location is noted above - please update your records.
Look for an invitation to our Open House event to showcase the new space in the coming months.

Melissa
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
endswitch

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

Regards,
~Bill

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

[Pathfinder-EA-logo-2]T: (585) 698-1956 F: (585) 325-6005
bbishop at pathfinder-ea.com www.pathfinder-ea.com
134 South Fitzhugh Street
Rochester, NY 14608 [cid:image008.png at 01D5FC51.3BD960B0] Ask me why Carbon Fee & Dividend may be right for you.

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

Bless you ~Bill!

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

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