# OT: modeling moving fenestration systems

Anyone know of commonly-used software which is used to model the kinematics of active fenestration systems? Or, for that matter, any building lighting element which moves?

Enquiring minds want to know!

Randolph

Hi Randolph,

I do not know of any software that can do this inherently. We have modeled these types of systems with Radiance. We use python to script up sets of Radiance runs, and within the python we have done transforms on objects before creating octrees. There is an example of an automated vertical louver system in my presentation at this years Radiance conference. FYI - Here is the chunk of python code that rotates the louvers. E-mail me if you would like to see the full python script. This is done on a time-by-time basis, so this code is in a larger loop that is going through each time step called for.

···

-------------------------------
ifp = os.popen( 'gensky %s %s %s +%s %s' % (sMonth[iSeason], sDay, sTime, sSky, aTmp[0]), 'r')
fAzi = float(aTmp3[17+len(aTmpA)])-fBAzi

# Determine slat rotation angle
if fAzi < -45:
fSlatAngle = 90
elif fAzi > 45:
fSlatAngle = 90
else:
fSlatAngle = -2*fAzi

fpOutFile = open ((sWorkingDir + os.sep + 'louver-temp.rad' ), 'w')
fpOutFile.write ('!xform -rz %f scene/louver.rad' % (fSlatAngle))
fpOutFile.close()

# Create Octree from base octree and sky
if fAzi < -75 or fAzi > 75:
os.system( 'oconv -w -i %s %s >%s' % \
(sOctree, (sViewDir + os.sep + 'hour.sky'), \
(sViewDir + os.sep + 'tmp.oct')))
else:
os.system( 'oconv -w -i %s %s %s >%s' % \
(sOctree, (sViewDir + os.sep + 'hour.sky'), (sWorkingDir + os.sep + 'all-louvers.rad'), \
(sViewDir + os.sep + 'tmp.oct')))
-------------------------------------

In my opinion, this is one of the great things about Radiance, it is so flexible and robust. It may take several years to fully understand everything, but when you do the options are limitless!

I hope this helps!
Zack

Zack Rogers, P.E., IESNA, LEED AP
Architectural Energy Corporation
2540 Frontier Avenue, Suite 201
Boulder, CO 80301 USA

tel (303)444-4149 ext. 435
fax (303)444-4304

-----Original Message-----
From: Randolph Fritz [mailto:[email protected]]
Sent: Monday, November 12, 2007 1:31 PM
Subject: [Radiance-general] OT: modeling moving fenestration systems

Anyone know of commonly-used software which is used to model the kinematics of active fenestration systems? Or, for that matter, any building lighting element which moves?

Enquiring minds want to know!

Randolph

_______________________________________________
[email protected]

Hi Randolph:

Daysim allow you to simulate dynamic shading devices such as Venetian blinds (www.daysim.com). The Daysim GUI only allows you to model the blinds in either up or down states but, as Zack suggested, you can use scripting to add as many intermediate blind states as you want. For an automatically controlled system such a external louvers that are maintained in cutoff position modeling many louver slat angle states might be worthwhile. For your typical 'reference system' (manual controlled Venetian blinds), I think that an up or down state is largely sufficient since we still know relatively little about how occupants actually operate blinds. Daysim incorporates the lightswithch 2002 algorithm that aims to mimic occupant behavior based on field studies. An interesting extension of the lightswitch algorithm was proposed by Jan Wienold at the Building Simulation 2007 conference in Beijing in September. You should be able to find the paper somewhere online.

Christoph

···

________________________________

From: [email protected] on behalf of Randolph Fritz
Sent: Mon 11/12/2007 3:31 PM
Subject: [Radiance-general] OT: modeling moving fenestration systems

Anyone know of commonly-used software which is used to model the
kinematics of active fenestration systems? Or, for that matter, any
building lighting element which moves?

Enquiring minds want to know!

Randolph

_______________________________________________