Xsurf

title: xsurf ---

  • .name: is that of of surface, door, window, perimeter, or mass (see x.ty) 1-92
  • .ownTi: ZNR subscript
Name Type Variability Description/Comments
nxXsurf TI Start of run 0 or XSRAT subscr of next record for zone. Chain head is ZNR.xsurf1.
nxXsSpecT TI Start of run addl chain of records w/ x.sfExCnd==C_EXCNDCH_SPECT: used hourly. Head is ZNR.xsSpecT1.
Name Type Variability Description/Comments
ty number Start of run type CTEXTWALL, CTINTWALL, CTWINDOW, CTMXWALL, CTPERIM, CTKIVA set by cult or code.

inputs. *r's where set by topCkf in at least some cases.

Name Type Variability Description/Comments
area AREA_GZ Start of run (net) area, ft2. Reflects window multiplier.
areaGlz AREA_GZ Start of run
  • glazed area, ft2. nz iff window
  • reflects window multiplier and frame fraction
azm ANGLE Start of run azimuth (radians, 0 = North, Pi/2 = East)
tilt ANGLE Start of run tilt (radians, 0 = horiz up, Pi/2 = vert.
dircos[index] number Array [3] Start of run outward normal direction cosines for given azm/tilt
depthBG FLOAT_GEZ Start of run depth below grade of bottom of wall, ft
height FLOAT_GEZ Start of run height of surface, ft (currently only used for Kiva)
model choice:SFMODEL Start of run
  • surface model: user input
  • quick/auto/delayed(massive)/delayed_hour/delayed_subhour/forward_difference/kiva
modelr choice:SFMODEL Start of run
  • resolved to quick (runtime XSURF generated),
  • or to delayed_hour or _subhour (runtime MASS generated)
  • or to kiva (runtime KIVA generated)
lThkF number Start of run
  • thickness factor, adjusts max thickness allowed for mass sublayers
  • default = 0.5
Name Type Variability Description/Comments
gti TI Start of run window glazeType subscript. Used at runtime re incidence angle.
sco number Start of monthly-hourly window: SMSO: Solar Heat Gain Coef multiplier, shades Open
scc number Start of monthly-hourly window: SMSC: Solar Heat Gain Coef, shades Closed
sbcI
  • inside (zone side) surface boundary conditions
  • ASHWAT windows: BCs at inside face of inside layer (glazing or shade; frame excluded, see xs_frmSbcI)
SBC
Name Type Variability Description/Comments
sbcI.absSlr number Start of monthly-hourly solar (SW) absorptance, dimless
sbcI.awAbsSlr DBL Start of monthly-hourly
  • area-weighted solar absorptance
  • = sb_absSlr * area / zn_surfASlr
  • exterior surf outside: always 0
  • windows inside: TBD 12-8-10
  • ducts: always 0
sbcI.epsLW number Start of run thermal (LW) emittance
sbcI.zi TI Start of run adjacent zone idx, 0 if exposed to ambient
sbcI.F DBL Start of run solar (short wave) fraction ? TODO: NOT USED? as of 4-2012
sbcI.Fp DBL Start of run
  • "view factor" to zone radiant temp, dimless. Includes Oppenheim surface conductance.
  • aka "F-prime" in CZM documentation.
Name Type Variability Description/Comments
sbcI.frRad DBL Start of run re radiant to radiant temp (room radiant node or sky)
sbcI.fSky DBL Start of run "view factor" to radiant surround at sky temp
sbcI.fAir DBL Start of run "view factor" to radiant surround at air temp (ground, horizon)
Name Type Variability Description/Comments
sbcI.hcNat FLOAT_GEZ End of subhour surface natural convection coefficient, Btuh/ft2-F
sbcI.hcFrc FLOAT_GEZ End of subhour surface forced (wind) convection coefficient, Btuh/ft2-F
sbcI.hcMult FLOAT_GEZ End of subhour surface convection coefficient multiplier, dimless
sbcI.hxa FLOAT_GEZ End of subhour overall coeff to sb_txa = sb_hcMult*(sb_hcNat + sb_hcFrc), Btuh/ft2-F
sbcI.hxr FLOAT_GEZ End of subhour
  • surface (linearized) radiative coefficient, Btuh/ft2-F
  • = coupling to sb_txr
sbcI.hxtot number End of subhour sb_hxa + sb_hxr
sbcI.uRat DBL End of subhour
  • ratio uC/(sb_hxa + sb_hxr + uC)
  • = 1/(1 + rC*(sb_hxa + sb_hxr))
  • where uC = surface-to-surface conductance
  • rC = 1/uC
  • but: duct model outside surf to duct air
Name Type Variability Description/Comments
sbcI.fRat DBL End of subhour
  • sb_hxtot * sb_uRat, Btuh/ft2-F
  • = overall conductance not including other side
  • surface resistances
  • (ducts: overall conductance from duct air to sb_txe)
sbcI.cx DBL End of subhour air/radiant coupling due to this surface, Btuh/ft2-F
Name Type Variability Description/Comments
sbcI.sgTarg solar gain target: bm, df gain from insolation
SGTARG
Name Type Variability Description/Comments
sbcI.sgTarg.bm DBL End of subhour beam
sbcI.sgTarg.df DBL End of subhour diffuse
sbcI.sgTarg.tot DBL End of subhour total
sbcI.sg DBL End of subhour absorbed solar total, Btuh (NOT Btuh/ft2), summed from sb_sgTarg
Name Type Variability Description/Comments
sbcI.tSrf number End of subhour most recently calculated surface temp, F
sbcI.tSrfls number Start of subhour
  • last step surface temp, F
  • copied from sb_tSrf at step end
  • not *e (available for probing)
sbcI.qrAbs DBL End of subhour
  • total absorbed radiant heat gain at surface, Btuh/ft2 (+ = into surface)
  • = (sb_sg + sb_rIg)/area
sbcI.txa number End of subhour
  • adjacent air temp, F (from prior step)
  • inside: prior step zone tz
  • outside: current step ambient dry bulb temp
sbcI.txr number End of subhour
  • adjacent radiant temp, F
  • inside: prior step zone tr
  • outside: current step sky temp
sbcI.txe number End of subhour
  • adjacent environmental temp, F
  • combined sb_txa and sb_txr; simplifies calcs in some cases
  • set but unused? for inside
  • set/used for ASHWAT outside
sbcI.w DBL End of subhour
  • adjacent air humidity ratio if known (else 0)
  • used re duct leakage
sbcI.qSrf DBL End of subhour
  • conduction into surface, Btuh/ft2
  • updated at end of timestep
Name Type Variability Description/Comments
sbcI.pXS XSURFP Start of run parent pointer
sbcI.si number Start of run
  • side of *sb_pXS represented by this SBC
  • 0=inside, 1=outside
sbcI.fcWind DBL Start of run
  • wind constant re sb_hcFrc (includes roughness, unit conversion, height adj, ...)
  • value is model specific
  • Walton: sb_hcFrc = sb_fcWind * Top.windSpeedSqrtSh
  • Unified: sb_hcFrc = sb_fcWind * Top.windSpeedPt8
sbcI.fcWind2 DBL Start of run unified: add'l constant re sb_eta
sbcI.eta DBL End of subhour
  • unified: wind speed adjustment included in sb_hcNat
  • windV=0: sb_eta=1, sb_hcNat=still-air value
  • windv>0: sb_eta<1, sb_hcNat is reduced
  • characteristic dimensions re convection models
  • not always set or used
  • Note: may be derived from parent surface TODO
Name Type Variability Description/Comments
sbcI.widNom DBL Start of run nominal width, ft (smaller dimension assuming rectangle)
sbcI.lenNom DBL Start of run nominal length, ft (larger dimension assuming rectangle)
sbcI.lenCharNat DBL Start of run characteristic length for some natural convection models, ft
sbcI.lenEffWink DBL Start of run effective length for Winkelmann forced convection model, ft
Name Type Variability Description/Comments
sbcI.cosTilt DBL Start of run
  • cos( Tilt ) for the boundary -- note parent surface tilt is defined
  • relative to outside normal (sbcO), so inside sb_cosTilt is oposite (+180 deg)
sbcI.atvDeg DBL Start of run angle-to-vertical, deg (inside: 90-tilt; outside: tilt-90)
sbcI.cosAtv DBL Start of run cos( angle to vertical) 0 - 1 (never < 0)
sbcI.hcModel choice:CONVMODEL Start of run
  • surface convective coefficient model
  • specifies calc method sb_hcNat and sb_hcFrc
sbcI.hcFrcOptions number Start of run
  • options re inside forced convection model
  • 1: use sb_hcFrcCoeffs (see code), else zn_hcFrc
sbcI.hcFrcCoeffs[index] number Array [4] Start of run
  • coefficients for forced convection model (inside only)
  • 1 extra array member required by cul
sbcI.hcLChar number Start of run
  • characteristic length, ft
  • used in derivation of exterior forced convective coeff
  • default = 10 ft
  • unused re natural convective coeff (interior or exterior)
sbcI.hcConst[index] DBL Array [3] Start of run
  • convection coefficient model constants
  • Unified: exposure to zone or ambient
  • hcNat = sb_hcConst[]*abs( TD)^.33)
  • [ 0]: tAir<=tSrf, [ 1]: tAir>tSrf
  • [ 2]: unused
  • ASHRAE: exposure to zone, hcNat = sb_hcConst[]
  • [ 0]: sys off, tAir<=tSrf, [ 1]: sys off, tAir>tSrf
  • [ 2]: sys on
  • re [sfExCnd][sfexcnd] = GROUND: conductances to weather vars, Btuh/ft2-F
  • correlation values derived by Bazjanac/Huang for various
  • insulation configurations
Name Type Variability Description/Comments
sbcI.groundModel choice:GROUNDMODEL Start of run
  • ground model in use (not input 1/1/2015)
  • C_GROUNDMODELCH_D2INP: DOE-2 model w/ user coeffs
  • C_GROUNDMODELCH_D2COR: DOE-2 model w/ correlation coeffs
sbcI.cTaDbAvgYr FLOAT_GEZ Start of run to annual avg taDb
sbcI.cTaDbAvg31 FLOAT_GEZ Start of run to last 31 day avg taDb
sbcI.cTaDbAvg14 FLOAT_GEZ Start of run to last 14 day avg taDb
sbcI.cTaDbAvg07 FLOAT_GEZ Start of run to last 7 day avg taDb
sbcI.cTGrnd FLOAT_GEZ Start of run to computed ground temp
sbcI.rGrnd FLOAT_GEZ Start of run resistance = 1/(sum of above) (0 if sum=0)
sbcI.rConGrnd FLOAT_GEZ Start of run
  • ground model implicit construction resistance, ft2-F/Btuh
  • = approx resistance of construction film/carpet/slab/soil
  • Caution: construction should be consistent with configuration
  • implicit in coefficient values.
sbcO
  • outside (ambient or adjacent zone) surface boundary conditions
  • ASHWAT windows: BCs at outside face of outside layer (glazing, screen, or shade; frame excluded, see xs_frmSbcO)
SBC
Name Type Variability Description/Comments
sbcO.absSlr number Start of monthly-hourly solar (SW) absorptance, dimless
sbcO.awAbsSlr DBL Start of monthly-hourly
  • area-weighted solar absorptance
  • = sb_absSlr * area / zn_surfASlr
  • exterior surf outside: always 0
  • windows inside: TBD 12-8-10
  • ducts: always 0
sbcO.epsLW number Start of run thermal (LW) emittance
sbcO.zi TI Start of run adjacent zone idx, 0 if exposed to ambient
sbcO.F DBL Start of run solar (short wave) fraction ? TODO: NOT USED? as of 4-2012
sbcO.Fp DBL Start of run
  • "view factor" to zone radiant temp, dimless. Includes Oppenheim surface conductance.
  • aka "F-prime" in CZM documentation.
Name Type Variability Description/Comments
sbcO.frRad DBL Start of run re radiant to radiant temp (room radiant node or sky)
sbcO.fSky DBL Start of run "view factor" to radiant surround at sky temp
sbcO.fAir DBL Start of run "view factor" to radiant surround at air temp (ground, horizon)
Name Type Variability Description/Comments
sbcO.hcNat FLOAT_GEZ End of subhour surface natural convection coefficient, Btuh/ft2-F
sbcO.hcFrc FLOAT_GEZ End of subhour surface forced (wind) convection coefficient, Btuh/ft2-F
sbcO.hcMult FLOAT_GEZ End of subhour surface convection coefficient multiplier, dimless
sbcO.hxa FLOAT_GEZ End of subhour overall coeff to sb_txa = sb_hcMult*(sb_hcNat + sb_hcFrc), Btuh/ft2-F
sbcO.hxr FLOAT_GEZ End of subhour
  • surface (linearized) radiative coefficient, Btuh/ft2-F
  • = coupling to sb_txr
sbcO.hxtot number End of subhour sb_hxa + sb_hxr
sbcO.uRat DBL End of subhour
  • ratio uC/(sb_hxa + sb_hxr + uC)
  • = 1/(1 + rC*(sb_hxa + sb_hxr))
  • where uC = surface-to-surface conductance
  • rC = 1/uC
  • but: duct model outside surf to duct air
Name Type Variability Description/Comments
sbcO.fRat DBL End of subhour
  • sb_hxtot * sb_uRat, Btuh/ft2-F
  • = overall conductance not including other side
  • surface resistances
  • (ducts: overall conductance from duct air to sb_txe)
sbcO.cx DBL End of subhour air/radiant coupling due to this surface, Btuh/ft2-F
Name Type Variability Description/Comments
sbcO.sgTarg solar gain target: bm, df gain from insolation
SGTARG
Name Type Variability Description/Comments
sbcO.sgTarg.bm DBL End of subhour beam
sbcO.sgTarg.df DBL End of subhour diffuse
sbcO.sgTarg.tot DBL End of subhour total
sbcO.sg DBL End of subhour absorbed solar total, Btuh (NOT Btuh/ft2), summed from sb_sgTarg
Name Type Variability Description/Comments
sbcO.tSrf number End of subhour most recently calculated surface temp, F
sbcO.tSrfls number Start of subhour
  • last step surface temp, F
  • copied from sb_tSrf at step end
  • not *e (available for probing)
sbcO.qrAbs DBL End of subhour
  • total absorbed radiant heat gain at surface, Btuh/ft2 (+ = into surface)
  • = (sb_sg + sb_rIg)/area
sbcO.txa number End of subhour
  • adjacent air temp, F (from prior step)
  • inside: prior step zone tz
  • outside: current step ambient dry bulb temp
sbcO.txr number End of subhour
  • adjacent radiant temp, F
  • inside: prior step zone tr
  • outside: current step sky temp
sbcO.txe number End of subhour
  • adjacent environmental temp, F
  • combined sb_txa and sb_txr; simplifies calcs in some cases
  • set but unused? for inside
  • set/used for ASHWAT outside
sbcO.w DBL End of subhour
  • adjacent air humidity ratio if known (else 0)
  • used re duct leakage
sbcO.qSrf DBL End of subhour
  • conduction into surface, Btuh/ft2
  • updated at end of timestep
Name Type Variability Description/Comments
sbcO.pXS XSURFP Start of run parent pointer
sbcO.si number Start of run
  • side of *sb_pXS represented by this SBC
  • 0=inside, 1=outside
sbcO.fcWind DBL Start of run
  • wind constant re sb_hcFrc (includes roughness, unit conversion, height adj, ...)
  • value is model specific
  • Walton: sb_hcFrc = sb_fcWind * Top.windSpeedSqrtSh
  • Unified: sb_hcFrc = sb_fcWind * Top.windSpeedPt8
sbcO.fcWind2 DBL Start of run unified: add'l constant re sb_eta
sbcO.eta DBL End of subhour
  • unified: wind speed adjustment included in sb_hcNat
  • windV=0: sb_eta=1, sb_hcNat=still-air value
  • windv>0: sb_eta<1, sb_hcNat is reduced
  • characteristic dimensions re convection models
  • not always set or used
  • Note: may be derived from parent surface TODO
Name Type Variability Description/Comments
sbcO.widNom DBL Start of run nominal width, ft (smaller dimension assuming rectangle)
sbcO.lenNom DBL Start of run nominal length, ft (larger dimension assuming rectangle)
sbcO.lenCharNat DBL Start of run characteristic length for some natural convection models, ft
sbcO.lenEffWink DBL Start of run effective length for Winkelmann forced convection model, ft
Name Type Variability Description/Comments
sbcO.cosTilt DBL Start of run
  • cos( Tilt ) for the boundary -- note parent surface tilt is defined
  • relative to outside normal (sbcO), so inside sb_cosTilt is oposite (+180 deg)
sbcO.atvDeg DBL Start of run angle-to-vertical, deg (inside: 90-tilt; outside: tilt-90)
sbcO.cosAtv DBL Start of run cos( angle to vertical) 0 - 1 (never < 0)
sbcO.hcModel choice:CONVMODEL Start of run
  • surface convective coefficient model
  • specifies calc method sb_hcNat and sb_hcFrc
sbcO.hcFrcOptions number Start of run
  • options re inside forced convection model
  • 1: use sb_hcFrcCoeffs (see code), else zn_hcFrc
sbcO.hcFrcCoeffs[index] number Array [4] Start of run
  • coefficients for forced convection model (inside only)
  • 1 extra array member required by cul
sbcO.hcLChar number Start of run
  • characteristic length, ft
  • used in derivation of exterior forced convective coeff
  • default = 10 ft
  • unused re natural convective coeff (interior or exterior)
sbcO.hcConst[index] DBL Array [3] Start of run
  • convection coefficient model constants
  • Unified: exposure to zone or ambient
  • hcNat = sb_hcConst[]*abs( TD)^.33)
  • [ 0]: tAir<=tSrf, [ 1]: tAir>tSrf
  • [ 2]: unused
  • ASHRAE: exposure to zone, hcNat = sb_hcConst[]
  • [ 0]: sys off, tAir<=tSrf, [ 1]: sys off, tAir>tSrf
  • [ 2]: sys on
  • re [sfExCnd][sfexcnd] = GROUND: conductances to weather vars, Btuh/ft2-F
  • correlation values derived by Bazjanac/Huang for various
  • insulation configurations
Name Type Variability Description/Comments
sbcO.groundModel choice:GROUNDMODEL Start of run
  • ground model in use (not input 1/1/2015)
  • C_GROUNDMODELCH_D2INP: DOE-2 model w/ user coeffs
  • C_GROUNDMODELCH_D2COR: DOE-2 model w/ correlation coeffs
sbcO.cTaDbAvgYr FLOAT_GEZ Start of run to annual avg taDb
sbcO.cTaDbAvg31 FLOAT_GEZ Start of run to last 31 day avg taDb
sbcO.cTaDbAvg14 FLOAT_GEZ Start of run to last 14 day avg taDb
sbcO.cTaDbAvg07 FLOAT_GEZ Start of run to last 7 day avg taDb
sbcO.cTGrnd FLOAT_GEZ Start of run to computed ground temp
sbcO.rGrnd FLOAT_GEZ Start of run resistance = 1/(sum of above) (0 if sum=0)
sbcO.rConGrnd FLOAT_GEZ Start of run
  • ground model implicit construction resistance, ft2-F/Btuh
  • = approx resistance of construction film/carpet/slab/soil
  • Caution: construction should be consistent with configuration
  • implicit in coefficient values.
frmSbcI ASHWAT windows: frame inside (zone side) surface boundary conditions
SBC
Name Type Variability Description/Comments
frmSbcI.absSlr number Start of monthly-hourly solar (SW) absorptance, dimless
frmSbcI.awAbsSlr DBL Start of monthly-hourly
  • area-weighted solar absorptance
  • = sb_absSlr * area / zn_surfASlr
  • exterior surf outside: always 0
  • windows inside: TBD 12-8-10
  • ducts: always 0
frmSbcI.epsLW number Start of run thermal (LW) emittance
frmSbcI.zi TI Start of run adjacent zone idx, 0 if exposed to ambient
frmSbcI.F DBL Start of run solar (short wave) fraction ? TODO: NOT USED? as of 4-2012
frmSbcI.Fp DBL Start of run
  • "view factor" to zone radiant temp, dimless. Includes Oppenheim surface conductance.
  • aka "F-prime" in CZM documentation.
Name Type Variability Description/Comments
frmSbcI.frRad DBL Start of run re radiant to radiant temp (room radiant node or sky)
frmSbcI.fSky DBL Start of run "view factor" to radiant surround at sky temp
frmSbcI.fAir DBL Start of run "view factor" to radiant surround at air temp (ground, horizon)
Name Type Variability Description/Comments
frmSbcI.hcNat FLOAT_GEZ End of subhour surface natural convection coefficient, Btuh/ft2-F
frmSbcI.hcFrc FLOAT_GEZ End of subhour surface forced (wind) convection coefficient, Btuh/ft2-F
frmSbcI.hcMult FLOAT_GEZ End of subhour surface convection coefficient multiplier, dimless
frmSbcI.hxa FLOAT_GEZ End of subhour overall coeff to sb_txa = sb_hcMult*(sb_hcNat + sb_hcFrc), Btuh/ft2-F
frmSbcI.hxr FLOAT_GEZ End of subhour
  • surface (linearized) radiative coefficient, Btuh/ft2-F
  • = coupling to sb_txr
frmSbcI.hxtot number End of subhour sb_hxa + sb_hxr
frmSbcI.uRat DBL End of subhour
  • ratio uC/(sb_hxa + sb_hxr + uC)
  • = 1/(1 + rC*(sb_hxa + sb_hxr))
  • where uC = surface-to-surface conductance
  • rC = 1/uC
  • but: duct model outside surf to duct air
Name Type Variability Description/Comments
frmSbcI.fRat DBL End of subhour
  • sb_hxtot * sb_uRat, Btuh/ft2-F
  • = overall conductance not including other side
  • surface resistances
  • (ducts: overall conductance from duct air to sb_txe)
frmSbcI.cx DBL End of subhour air/radiant coupling due to this surface, Btuh/ft2-F
Name Type Variability Description/Comments
frmSbcI.sgTarg solar gain target: bm, df gain from insolation
SGTARG
Name Type Variability Description/Comments
frmSbcI.sgTarg.bm DBL End of subhour beam
frmSbcI.sgTarg.df DBL End of subhour diffuse
frmSbcI.sgTarg.tot DBL End of subhour total
frmSbcI.sg DBL End of subhour absorbed solar total, Btuh (NOT Btuh/ft2), summed from sb_sgTarg
Name Type Variability Description/Comments
frmSbcI.tSrf number End of subhour most recently calculated surface temp, F
frmSbcI.tSrfls number Start of subhour
  • last step surface temp, F
  • copied from sb_tSrf at step end
  • not *e (available for probing)
frmSbcI.qrAbs DBL End of subhour
  • total absorbed radiant heat gain at surface, Btuh/ft2 (+ = into surface)
  • = (sb_sg + sb_rIg)/area
frmSbcI.txa number End of subhour
  • adjacent air temp, F (from prior step)
  • inside: prior step zone tz
  • outside: current step ambient dry bulb temp
frmSbcI.txr number End of subhour
  • adjacent radiant temp, F
  • inside: prior step zone tr
  • outside: current step sky temp
frmSbcI.txe number End of subhour
  • adjacent environmental temp, F
  • combined sb_txa and sb_txr; simplifies calcs in some cases
  • set but unused? for inside
  • set/used for ASHWAT outside
frmSbcI.w DBL End of subhour
  • adjacent air humidity ratio if known (else 0)
  • used re duct leakage
frmSbcI.qSrf DBL End of subhour
  • conduction into surface, Btuh/ft2
  • updated at end of timestep
Name Type Variability Description/Comments
frmSbcI.pXS XSURFP Start of run parent pointer
frmSbcI.si number Start of run
  • side of *sb_pXS represented by this SBC
  • 0=inside, 1=outside
frmSbcI.fcWind DBL Start of run
  • wind constant re sb_hcFrc (includes roughness, unit conversion, height adj, ...)
  • value is model specific
  • Walton: sb_hcFrc = sb_fcWind * Top.windSpeedSqrtSh
  • Unified: sb_hcFrc = sb_fcWind * Top.windSpeedPt8
frmSbcI.fcWind2 DBL Start of run unified: add'l constant re sb_eta
frmSbcI.eta DBL End of subhour
  • unified: wind speed adjustment included in sb_hcNat
  • windV=0: sb_eta=1, sb_hcNat=still-air value
  • windv>0: sb_eta<1, sb_hcNat is reduced
  • characteristic dimensions re convection models
  • not always set or used
  • Note: may be derived from parent surface TODO
Name Type Variability Description/Comments
frmSbcI.widNom DBL Start of run nominal width, ft (smaller dimension assuming rectangle)
frmSbcI.lenNom DBL Start of run nominal length, ft (larger dimension assuming rectangle)
frmSbcI.lenCharNat DBL Start of run characteristic length for some natural convection models, ft
frmSbcI.lenEffWink DBL Start of run effective length for Winkelmann forced convection model, ft
Name Type Variability Description/Comments
frmSbcI.cosTilt DBL Start of run
  • cos( Tilt ) for the boundary -- note parent surface tilt is defined
  • relative to outside normal (sbcO), so inside sb_cosTilt is oposite (+180 deg)
frmSbcI.atvDeg DBL Start of run angle-to-vertical, deg (inside: 90-tilt; outside: tilt-90)
frmSbcI.cosAtv DBL Start of run cos( angle to vertical) 0 - 1 (never < 0)
frmSbcI.hcModel choice:CONVMODEL Start of run
  • surface convective coefficient model
  • specifies calc method sb_hcNat and sb_hcFrc
frmSbcI.hcFrcOptions number Start of run
  • options re inside forced convection model
  • 1: use sb_hcFrcCoeffs (see code), else zn_hcFrc
frmSbcI.hcFrcCoeffs[index] number Array [4] Start of run
  • coefficients for forced convection model (inside only)
  • 1 extra array member required by cul
frmSbcI.hcLChar number Start of run
  • characteristic length, ft
  • used in derivation of exterior forced convective coeff
  • default = 10 ft
  • unused re natural convective coeff (interior or exterior)
frmSbcI.hcConst[index] DBL Array [3] Start of run
  • convection coefficient model constants
  • Unified: exposure to zone or ambient
  • hcNat = sb_hcConst[]*abs( TD)^.33)
  • [ 0]: tAir<=tSrf, [ 1]: tAir>tSrf
  • [ 2]: unused
  • ASHRAE: exposure to zone, hcNat = sb_hcConst[]
  • [ 0]: sys off, tAir<=tSrf, [ 1]: sys off, tAir>tSrf
  • [ 2]: sys on
  • re [sfExCnd][sfexcnd] = GROUND: conductances to weather vars, Btuh/ft2-F
  • correlation values derived by Bazjanac/Huang for various
  • insulation configurations
Name Type Variability Description/Comments
frmSbcI.groundModel choice:GROUNDMODEL Start of run
  • ground model in use (not input 1/1/2015)
  • C_GROUNDMODELCH_D2INP: DOE-2 model w/ user coeffs
  • C_GROUNDMODELCH_D2COR: DOE-2 model w/ correlation coeffs
frmSbcI.cTaDbAvgYr FLOAT_GEZ Start of run to annual avg taDb
frmSbcI.cTaDbAvg31 FLOAT_GEZ Start of run to last 31 day avg taDb
frmSbcI.cTaDbAvg14 FLOAT_GEZ Start of run to last 14 day avg taDb
frmSbcI.cTaDbAvg07 FLOAT_GEZ Start of run to last 7 day avg taDb
frmSbcI.cTGrnd FLOAT_GEZ Start of run to computed ground temp
frmSbcI.rGrnd FLOAT_GEZ Start of run resistance = 1/(sum of above) (0 if sum=0)
frmSbcI.rConGrnd FLOAT_GEZ Start of run
  • ground model implicit construction resistance, ft2-F/Btuh
  • = approx resistance of construction film/carpet/slab/soil
  • Caution: construction should be consistent with configuration
  • implicit in coefficient values.
frmSbcO ASHWAT windows: frame outside (ambient) surface boundary conditions
SBC
Name Type Variability Description/Comments
frmSbcO.absSlr number Start of monthly-hourly solar (SW) absorptance, dimless
frmSbcO.awAbsSlr DBL Start of monthly-hourly
  • area-weighted solar absorptance
  • = sb_absSlr * area / zn_surfASlr
  • exterior surf outside: always 0
  • windows inside: TBD 12-8-10
  • ducts: always 0
frmSbcO.epsLW number Start of run thermal (LW) emittance
frmSbcO.zi TI Start of run adjacent zone idx, 0 if exposed to ambient
frmSbcO.F DBL Start of run solar (short wave) fraction ? TODO: NOT USED? as of 4-2012
frmSbcO.Fp DBL Start of run
  • "view factor" to zone radiant temp, dimless. Includes Oppenheim surface conductance.
  • aka "F-prime" in CZM documentation.
Name Type Variability Description/Comments
frmSbcO.frRad DBL Start of run re radiant to radiant temp (room radiant node or sky)
frmSbcO.fSky DBL Start of run "view factor" to radiant surround at sky temp
frmSbcO.fAir DBL Start of run "view factor" to radiant surround at air temp (ground, horizon)
Name Type Variability Description/Comments
frmSbcO.hcNat FLOAT_GEZ End of subhour surface natural convection coefficient, Btuh/ft2-F
frmSbcO.hcFrc FLOAT_GEZ End of subhour surface forced (wind) convection coefficient, Btuh/ft2-F
frmSbcO.hcMult FLOAT_GEZ End of subhour surface convection coefficient multiplier, dimless
frmSbcO.hxa FLOAT_GEZ End of subhour overall coeff to sb_txa = sb_hcMult*(sb_hcNat + sb_hcFrc), Btuh/ft2-F
frmSbcO.hxr FLOAT_GEZ End of subhour
  • surface (linearized) radiative coefficient, Btuh/ft2-F
  • = coupling to sb_txr
frmSbcO.hxtot number End of subhour sb_hxa + sb_hxr
frmSbcO.uRat DBL End of subhour
  • ratio uC/(sb_hxa + sb_hxr + uC)
  • = 1/(1 + rC*(sb_hxa + sb_hxr))
  • where uC = surface-to-surface conductance
  • rC = 1/uC
  • but: duct model outside surf to duct air
Name Type Variability Description/Comments
frmSbcO.fRat DBL End of subhour
  • sb_hxtot * sb_uRat, Btuh/ft2-F
  • = overall conductance not including other side
  • surface resistances
  • (ducts: overall conductance from duct air to sb_txe)
frmSbcO.cx DBL End of subhour air/radiant coupling due to this surface, Btuh/ft2-F
Name Type Variability Description/Comments
frmSbcO.sgTarg solar gain target: bm, df gain from insolation
SGTARG
Name Type Variability Description/Comments
frmSbcO.sgTarg.bm DBL End of subhour beam
frmSbcO.sgTarg.df DBL End of subhour diffuse
frmSbcO.sgTarg.tot DBL End of subhour total
frmSbcO.sg DBL End of subhour absorbed solar total, Btuh (NOT Btuh/ft2), summed from sb_sgTarg
Name Type Variability Description/Comments
frmSbcO.tSrf number End of subhour most recently calculated surface temp, F
frmSbcO.tSrfls number Start of subhour
  • last step surface temp, F
  • copied from sb_tSrf at step end
  • not *e (available for probing)
frmSbcO.qrAbs DBL End of subhour
  • total absorbed radiant heat gain at surface, Btuh/ft2 (+ = into surface)
  • = (sb_sg + sb_rIg)/area
frmSbcO.txa number End of subhour
  • adjacent air temp, F (from prior step)
  • inside: prior step zone tz
  • outside: current step ambient dry bulb temp
frmSbcO.txr number End of subhour
  • adjacent radiant temp, F
  • inside: prior step zone tr
  • outside: current step sky temp
frmSbcO.txe number End of subhour
  • adjacent environmental temp, F
  • combined sb_txa and sb_txr; simplifies calcs in some cases
  • set but unused? for inside
  • set/used for ASHWAT outside
frmSbcO.w DBL End of subhour
  • adjacent air humidity ratio if known (else 0)
  • used re duct leakage
frmSbcO.qSrf DBL End of subhour
  • conduction into surface, Btuh/ft2
  • updated at end of timestep
Name Type Variability Description/Comments
frmSbcO.pXS XSURFP Start of run parent pointer
frmSbcO.si number Start of run
  • side of *sb_pXS represented by this SBC
  • 0=inside, 1=outside
frmSbcO.fcWind DBL Start of run
  • wind constant re sb_hcFrc (includes roughness, unit conversion, height adj, ...)
  • value is model specific
  • Walton: sb_hcFrc = sb_fcWind * Top.windSpeedSqrtSh
  • Unified: sb_hcFrc = sb_fcWind * Top.windSpeedPt8
frmSbcO.fcWind2 DBL Start of run unified: add'l constant re sb_eta
frmSbcO.eta DBL End of subhour
  • unified: wind speed adjustment included in sb_hcNat
  • windV=0: sb_eta=1, sb_hcNat=still-air value
  • windv>0: sb_eta<1, sb_hcNat is reduced
  • characteristic dimensions re convection models
  • not always set or used
  • Note: may be derived from parent surface TODO
Name Type Variability Description/Comments
frmSbcO.widNom DBL Start of run nominal width, ft (smaller dimension assuming rectangle)
frmSbcO.lenNom DBL Start of run nominal length, ft (larger dimension assuming rectangle)
frmSbcO.lenCharNat DBL Start of run characteristic length for some natural convection models, ft
frmSbcO.lenEffWink DBL Start of run effective length for Winkelmann forced convection model, ft
Name Type Variability Description/Comments
frmSbcO.cosTilt DBL Start of run
  • cos( Tilt ) for the boundary -- note parent surface tilt is defined
  • relative to outside normal (sbcO), so inside sb_cosTilt is oposite (+180 deg)
frmSbcO.atvDeg DBL Start of run angle-to-vertical, deg (inside: 90-tilt; outside: tilt-90)
frmSbcO.cosAtv DBL Start of run cos( angle to vertical) 0 - 1 (never < 0)
frmSbcO.hcModel choice:CONVMODEL Start of run
  • surface convective coefficient model
  • specifies calc method sb_hcNat and sb_hcFrc
frmSbcO.hcFrcOptions number Start of run
  • options re inside forced convection model
  • 1: use sb_hcFrcCoeffs (see code), else zn_hcFrc
frmSbcO.hcFrcCoeffs[index] number Array [4] Start of run
  • coefficients for forced convection model (inside only)
  • 1 extra array member required by cul
frmSbcO.hcLChar number Start of run
  • characteristic length, ft
  • used in derivation of exterior forced convective coeff
  • default = 10 ft
  • unused re natural convective coeff (interior or exterior)
frmSbcO.hcConst[index] DBL Array [3] Start of run
  • convection coefficient model constants
  • Unified: exposure to zone or ambient
  • hcNat = sb_hcConst[]*abs( TD)^.33)
  • [ 0]: tAir<=tSrf, [ 1]: tAir>tSrf
  • [ 2]: unused
  • ASHRAE: exposure to zone, hcNat = sb_hcConst[]
  • [ 0]: sys off, tAir<=tSrf, [ 1]: sys off, tAir>tSrf
  • [ 2]: sys on
  • re [sfExCnd][sfexcnd] = GROUND: conductances to weather vars, Btuh/ft2-F
  • correlation values derived by Bazjanac/Huang for various
  • insulation configurations
Name Type Variability Description/Comments
frmSbcO.groundModel choice:GROUNDMODEL Start of run
  • ground model in use (not input 1/1/2015)
  • C_GROUNDMODELCH_D2INP: DOE-2 model w/ user coeffs
  • C_GROUNDMODELCH_D2COR: DOE-2 model w/ correlation coeffs
frmSbcO.cTaDbAvgYr FLOAT_GEZ Start of run to annual avg taDb
frmSbcO.cTaDbAvg31 FLOAT_GEZ Start of run to last 31 day avg taDb
frmSbcO.cTaDbAvg14 FLOAT_GEZ Start of run to last 14 day avg taDb
frmSbcO.cTaDbAvg07 FLOAT_GEZ Start of run to last 7 day avg taDb
frmSbcO.cTGrnd FLOAT_GEZ Start of run to computed ground temp
frmSbcO.rGrnd FLOAT_GEZ Start of run resistance = 1/(sum of above) (0 if sum=0)
frmSbcO.rConGrnd FLOAT_GEZ Start of run
  • ground model implicit construction resistance, ft2-F/Btuh
  • = approx resistance of construction film/carpet/slab/soil
  • Caution: construction should be consistent with configuration
  • implicit in coefficient values.
Name Type Variability Description/Comments
fenModel choice:FENMODEL Start of run fenestration model: user input
SHGC number Start of run rated SHGC of assembly
fMult FLOAT_GEZ Start of run window frame/mullion multiplier (input or from GT)
UNFRC UH_GZ Start of run overall U-factor evaluated under per NFRC heating conditions
NGlz number Start of run # of glazings bare-glass assembly
exShd choice:EXSHD Start of run exterior shade (ASHWAT only)
inShd choice:INSHD Start of run interior shade (ditto)
dirtLoss FLOAT_GEZ Start of run window dirt loss factor (input or from GT)

next 3 are input for surface, copied from surface of door or window

Name Type Variability Description/Comments
sfExCnd choice:EXCND Start of run adjacent cond: adiabatic/ambient/specT/adjZn.
sfExT TEMP Start of subhour outside temp if .sfExCnd==C_EXCNDCH_SPECT
sfAdjZi TI Start of run zone for sfExCnd==ADJZN, or 0 for exterior surface/door/window.
uI UH_GZ Start of run interior surf (air film) conductance. input.
uC UH_GZ Start of run uval of construction, excl surfaces (air films). From CON, GT, or SFI.sfU user input.
uX UH_GZ Start of run exterior surface (air film) conductance. input.
Rf number Start of run
  • exterior roughness factor, re convection (new 10-10)
  • default: windows=1, all others=2.17
grndRefl number Start of monthly-hourly ground reflectivity, default: wall: Top.grndRefl; door/win: owning wall.

view factors for diffuse (only) radiation so user can precompute shading effects of window overhang/fins

Name Type Variability Description/Comments
vfSkyDf number Start of monthly-hourly sky view factor for diffuse solar, default .5 + .5*cos(tilt)
vfGrndDf number Start of monthly-hourly ground view factor for diffuse solar, default .5 - .5*cos(tilt)

view factors re outside surface LW (thermal) radiant exchange

Name Type Variability Description/Comments
vfSkyLW number Start of run sky view factor for long-wave radiation, hard-coded .5 + .5*cos( tilt)
vfGrndLW number Start of run ground view factor for long-wave radiation, hard-coded .5 - .5*cos( tilt)
Name Type Variability Description/Comments
uval UH_GZ Start of run
  • Overall air-to-air conductance, Btuh/sf-F
  • includes uX and uC surf cond
  • *Nominal* U-factor etc including ASHRAE heating surface resistance
  • documentation only!
Name Type Variability Description/Comments
UNom UH_GZ Start of run nominal air-to-air U-factor, Btuh/sf-F
UANom UA Start of run
  • area * xs_UNom, Btuh/F
  • surface values, [0]=inside, [1]=outside
rSrfNom[index] number Array [2] Start of run surface resistance sf-F/Btuh
hSrfNom[index] number Array [2] Start of run surface conductance (1/xs_rSrfNom), Btuh/sf-F
Name Type Variability Description/Comments
cFctr UH_GZ Start of run surface-to-surface conductance (not populated!)
Name Type Variability Description/Comments
iwshad TI Start of run 0 if none or subscr in WSHADRAT of overhang/fin info for a shaded window
msi TI Start of run 0, or mass (MsR) subscript for CTMXWALL.

solar gain distributions: [partly] based on SGDIST inputs

Name Type Variability Description/Comments
nsgdist number Start of run
  • Number of SG distributions
  • [SGDIST][sgdist] sgdist[ HSMXSGDIST]:
sgdist[index] Array [8]
  • =8 (2-95), cndefns.h. explicit solar gain distribs
  • *r -> min variation here: no members set at input time
  • *nest [SGDIST][sgdist] sgdist -> solar gain distribution (struct just above). set: cncult3.cpp:cnuSgDist().
SGDIST
Name Type Variability Description/Comments
sgdist[index].targTy number Start of run
  • target type: define (cnguts.h) basAnc & member
  • zone air SGDTTZNAIR ZNR.qSgAir
  • (zone check/results total SGDTTZNTOT ZNR.qSgTot/qSgTotSh (not here; gen'd in cgsolar 2-95)
  • surface in/outside SGDTSURFI/O
sgdist[index].targTi TI Start of run subscript of targeted entry in RAT above: *i in SGI; *nest merges variation flags.
sgdist[index].FSO number Start of monthly-hourly frac of gain to target, shades open
sgdist[index].FSC number Start of monthly-hourly frac of gain to target, shades closed (defaults to sgd_FSO)

runtime values

Name Type Variability Description/Comments
glzTrans number End of subhour ASHWAT windows: transmitted solar gain, Btuh/ft2 (w/o cavity absorp adjustment)
glzInward number End of subhour ASHWAT windows: inward flowing convective and LW radiant gain to zone, Btuh/ft2
Name Type Variability Description/Comments
tLrB[index] number Array [10] End of hour
  • layer boundary temps re probes
  • populated at end of hour