Zone

title: zone --- ZNISUB general user inputs

Name Type Variability Description/Comments
znModel choice:ZNMODEL input time zone model (CNE, CSE, CZM, UZM, UZX)
znArea AREA_GZ input time flrarea Conditioned floor area of zone (ft2)
znVol VOL_GZ input time zone nominal volume (ft3)
floorZ number input time
  • zone floor Z above ground, ft. Used re airNet vent Z etc.
  • (can be <0 re below grade spaces)
ceilingHt LEN_GZ Start of run zone nominal ceiling height, ft. default = znVol / znArea
znCAir HC_GZ input time
  • effective "air" heat cap (Btu/F): models all non-mass heat cap in zone.
  • defaults to 3.5*area. heat cap of surfaces not modelled as "massive" may be added.
HIRatio FLOAT_GZ Start of run
  • hygric inertia ratio for zone, default 1
  • for moisture balance calcs in non-CNE zones,
  • effective dry-air mass = zn_HIRatio * zn_dryAirMass
znAzm ANGLE input time zone azimuth wrt bldgAzm, deg. + = clockwise
plenumRet BOO input time
  • TRUE for plenum return, FALSE for ducted return, for all air from this zone. default FALSE. 3-92.
  • not yet inputtable 10-92. If changed eg to yes-no fix cncult5 errmsg "...when zone plenumRet is 0".
  • ** where is the plenum, and whether it is active or passive, specified?
znSC number Start of hour
  • zone Shade Closure optional hourly expression, 0. open, 1. closed.
  • default: closed if cooling in prior hour (cnloads::loadsAfterHour) (see ZNR:znSCF)
  • Determines choice between window sco/scc, [SGDIST][sgdist] sgd_FSC/sfFSC, via cgsolar.cpp.
  • Pointed to by .cppontrol of SgR entries (whose factors are (neg) closed-shade gain reductions).
  • Subhourly variablility desirable (rob's opinion); requires duplicating
  • loadsHourBeg solar gain code in loadsSubhr with [znSC][znsc]-change trigger.
Name Type Variability Description/Comments
znTH TEMP_GZ Start of subhour base heating set point, F (from input, may be modified for autosizing)
znTD TEMP_GZ Start of subhour base desired temp (vent) set point, F (from input, may be modified for autosizing)
znTC TEMP_GZ Start of subhour base cooling set point, F (from input, may be modified for autosizing)

available nominal system capacity, Btuh (added 9-10)

Name Type Variability Description/Comments
znQMxH number Start of hour heating cap for current hour (>= 0)
znQMxHRated number Start of run heating cap rated (>=0, constant for run) TODO: s/b autosizable?
znQMxC number Start of hour cooling cap for current hour (<= 0)
znQMxCRated number Start of run cooling cap rated (<=0, constant for run) TODO: s/b autosizable?
loadMtri TI Start of run idx of LOADMETER for accumulation of zone heating and cooling loads
Name Type Variability Description/Comments
rsi TI Start of run idx of RSYS serving zone
Name Type Variability Description/Comments
hcFrcF number Start of hour
  • forced convection coefficient factor, default = 0.2
  • interior hcFrc = zn_hcFrcF * zn_hcAirX^.8
hcAirX number End of subhour
  • zone air change rate (1/hr), input for testing
  • else calculated subhourly in zn_AirXMoistureBal()
hcAirXIsSet number Start of run
  • 1 iff zn_hcAirX is set from input (for testing)
  • WHY: ZNI status bytes not passed to ZNR, need flag

Zone exhaust fan members (from Taylor's terminal description 3-92)

Name Type Variability Description/Comments
xfanFOn number Start of hour zone exhaust fan schedule, fraction on, hourly scheduleable, default 1
xfan
  • subrecord for other fan members.
  • if xfan.vfDs is not given, no fan, other inputs disallowed.
FAN
Name Type Variability Description/Comments
xfan.fanTy choice:FANTY Start of phase
  • fan position choice, according to application as follows; constant.
  • air handler supply: DRAWTHRU (default) or BLOWTHRU
  • ah return/relief: NONE (default), RETURN, or RELIEF
  • terminal: NONE (default), SERIES, or PARALLEL
  • zone exhaust fan: NONE or EXHAUST (no types, just whether exists)
  • AirNet ([IZXFER][izxfer]): ditto
xfan.vfDs AFLOW_GZ End of subhour design volumetric flow (cfm actual air). constant, RQD except as noted. *s cuz varies when autoSizing.
xfan.vfDs_As AFLOW Start of phase autoSized ditto for ah sfan and rfan for naming consistency. 6-95.
xfan.vfDs_AsNov AFLOW Start of phase
  • raw autoSized ditto b4 overSize added, for report/probes. 7-95.
  • cnausz.cpp code ASSUMES x, x_As, x_AsNov together for access thru one ptr. cuprobe.cpp's name search also requires together.
xfan.vfMxF number Start of phase
  • factor by which fan flow will exceed vfDs (at reduced pressure). default 1.3. constant.
  • Error if < 1.0; typically <= 1.5.
Name Type Variability Description/Comments
xfan.press PRESAIR_GEZ Start of run
  • system design pressure, "H2O (inches of water), constant, used in defaulting power / efficiency.
  • default: supply 3, r/r .75, tu .3, zx ???.
  • 0 allowed 5-1-92 to eliminate fan heat for test/calibration purposes.
only one of eff and shaftPwr may be given:
Name Type Variability Description/Comments
xfan.eff FRAC_GZ Start of run
  • fan (hydraulic) efficiency at vfDs and press (any temp), constant,
  • default from power if given, else .65. (1-eff) of fan shaft power is converted to heat in airstream.
xfan.shaftPwr BHP_GZ Start of run
  • fan shaft power at vfDs and press (any temp). constant. default: from eff
  • Btuh internally, entered in BHP (user name 'shaftBhp') (cvpak converts).
  • ^^^^make user name 'shaftBhp'. field type name??
xfan.elecPwr FLOAT_GZ Start of run
  • motor input power, W/cfm (based on vfDs); shaftPwr and elecPwr cannot both be
  • input
Name Type Variability Description/Comments
xfan.motTy choice:MOTTY Start of run
  • motor type (C_MOTTYCH_PSC or C_MOTTYCH_BPM)
  • [RSYS][rsys] only minimal use 4-12, could effect defaults
Name Type Variability Description/Comments
xfan.motEff FRAC_GZ Start of phase motor/drive efficiency, constant, default .9.
Name Type Variability Description/Comments
xfan.motPos choice:MOTPOS Start of phase
  • motor/drive position: choice of INFLO (default), INRETURN, EXTERNAL. constant.
  • INRETURN is for supply fans only and will be deferred/omitted if difficult
  • chip per taylor 3-4-92).
Name Type Variability Description/Comments
xfan.curvePy fan part-load energy consumption curve cubic polynomial coefficients with x0
PYCUBIC2
Name Type Variability Description/Comments
xfan.curvePy.k[index] number Array [6] Start of phase FLOAT k[6]. [0..3] are coeff, [4] is minimum x, [5] is terminator needed by cul.cpp.
Name Type Variability Description/Comments
xfan.mtri TI input time subscript of meter (MTR) to which energy consumption is charged
xfan.endUse choice:ENDUSE Start of phase
  • end use to which energy consumption is charged
  • not used for all fans (many implicitly default to "fan")
Name Type Variability Description/Comments
xfan.ausz BOO Start of run
  • non-0 if fan being autoSized (AH sfan, rfan): input contained [AUTOSIZE][autosize] _fanVfDs. 7-1-95.
  • see also AH::fanAs, asRfan, asFlow. 7-1-95. */
  • FAN setup time members, set by cnfan.cpp:FAN::setup. May be resetup during autoSize run.
  • also cMx may be init by setup, to be non-0.
Name Type Variability Description/Comments
xfan.outPower number Start of subhour
  • motor output power (work done by fan), member 7-95 for one setup check in cncult5.cpp
  • inPower = shaftPwr/motEff is computed as needed.
xfan.airPower number Start of subhour
  • fan heat to air (Btuh) at vfDs (& pressure): work done by fan, plus motor/drive inefficiency if in flow.
  • Note work done by fan is modelled as HEAT ADDED TO AIR AT FAN per Chip/Niles (3-92, undocumented)
  • heat to air around motor (in return air etc) at design flow is: (inPower - airPower). this is 0 if motor in air flow.
FAN runtime members, set by cnah.cpp:FAN::pute( cFlow, temp)
Name Type Variability Description/Comments
xfan.cMx CFLOW End of subhour max heat cap flow (Btuh/F) at curr air temp & run press & ref w: .vfMx * air vsh * 60 (min/hr)
xfan.c CFLOW End of subhour current average flow in heat cap units (Btuh/F): input saved for probing by last call to FAN::pute()
xfan.t TEMP End of subhour current air temp, input saved ditto, used in converting BtuF/F to cfm
xfan.frOn number End of subhour
  • fraction of time fan is on, saved input
  • made local to pute()to save members 10-92:
  • *s *e FRAC relFlow // fraction of design flow
  • *s *e FRAC relLoad // fraction of full load per part load curve for fan type (1.0 if over design flow: assume pressure drops)
xfan.p number End of subhour (motor) power consumption for subhour -- inPower * relLoad. *subhrDur for meter.
xfan.q number End of subhour heat (power) to air this subhour: airPower * relLoad. Member needed in addition to c and dT??
xfan.dT TEMPDIFF End of subhour temp difference due to fan: q/c
xfan.qAround number End of subhour heat to air around motor, if not in air flow, for use re supply fan motor in return air

ZNISUB infiltration inputs.

Name Type Variability Description/Comments
infAC FLOAT_GEZ Start of hour ac Base air changes/hr, for q proportional to tempDiff ("constant" portion). (1/hr)
infELA AREA2 Start of hour
  • ela Zone effective leakage area, for q prop to tempDiff ^ 3/2 (cuz flow prop to sqrt(tDiff))
  • (in2 to user, ft2 internally)
infShld SI_GZ constant local shielding (obstructions) class (1 - 5)
infStories SI_GZ constant # stories in zone (1-3); provides default for zn_eaveZ else unused
eaveZ LEN_GZ Start of run
  • zone nominal eave Z above ground, ft re wind speed adjustment
  • default = zn_floorZ + zn_infStories * 8.f;
windFLkg number Start of subhour
  • wind factor for infiltration and airnet, dimless
  • default derived from zn_infShld and zn_eaveZ
  • else input
  • Note: Top.[windF][windf] also applied
afMtri TI Start of run
  • AFMTR (air flow meter) idx, 0 if none
  • provides default for IZXRAT.iz_afMtri in this zone
  • perhaps additional?

ZNISUB setup time: reports. (Most zone report info is in DvriB, accessed by interval via list heads in Top.)

Name Type Variability Description/Comments
vrZdd number Start of run
  • 0 (report not requested) or vrh (virtual report handle) for zone description (ZDD report).
  • in ZNISUB to persist from autosize to main sim, when most runtime stuff is cleared & resetup,
  • incl zones but excluding most report stuff.

ZNR setup time: zone's objects

Name Type Variability Description/Comments
xsurf1 TI Start of run chain head (XSRAT subscr) of zone's XSURFs: surface/window/perim/massWall info. next: XSRAT.nxXsurf.
xsSpecT1 TI Start of run 0 or chain head of zn's XSURFs with .sfExCnd==C_EXCNDCH_SPECT: used hourly. next: XSRAT.nxXsSpecT.
tu1 TI Start of run head of chain of zone's terminals: 0 or TuB subscript. next: TU.nxTu.
zhx1 TI Start of run chain head of zone's ZHX's (Zone Hvac Xfers): 0 or ZhxB subscript. next: ZHX.nxZhx4z.
zhx1St TI Start of run ... zone's cmStxx (tstat-ctrl'd) ZHX's. next: ZHX.nxZhzSt4z.
airTerminalCount number Start of run
  • # of terminals serving this zone that can supply air
  • known after all TU::tu_Setup()s complete
anPathLenToAmbient number Start of run
  • zone shortest path length to ambient pressure
  • based on [IZXFER][izxfer] network
  • -1: no path (AirNet troubles probable)
  • 0: this zone has exterior vents
  • 1: an [IZXFER][izxfer]-adjacent zone has exterior vents
  • 2: etc.
anVentCount[index] number Array [3] Start of run
  • count of airnet vents connected to this zone
  • re validation of AIRNET configuration
  • [0]=exterior pressure-dependent [1] IZ pressure dependent [2]=fixed flow

ZNR setup time: other

Name Type Variability Description/Comments
znSCF BOO Start of run non-0 if i.znSC given by user; 0 to default Shade Closure in cnloads.cpp

ZNR infiltration setup time info, set by ZNR.zn_InfilSetup() for cnloads:loadsHourBeg. Double infiltration model is supported.

Name Type Variability Description/Comments
stackc number Start of run stack coefficient for zone height (Sherman-Grimsrud model)
windc number Start of run wind coefficient for zone height and shielding (Sherman-Grimsrud model)
  • ZNR radiant internal gain setup time info, 11-95
  • Radiant internal gains distribution table entry use: Much redundant info for debugging / poss future repoint needs.
  • struct { RIGTARGTY targTy; TI targTi; float targFr; RIGTARG * targP; }; (cndtypes.def)
  • .targTy .targTi is for target member description
  • znTot ZNR .qrIgTot zone total rIg, for ebal check
  • znTotO -- .qrIgTotO loss thru light surf to outdoors, for conduction in ebal check
  • znTotIz ZNR .qrIgTotIz to adjacent zone thru light surf (entries for both zones, + and -)
  • [znCAir][zncair] ZNR .qrIgCAir to zone CAir (light surface)
  • massI MSRAT .inside.qIg to mass inside in this zone
  • massO MSRAT .outside.qIg to mass outside in this zone
Name Type Variability Description/Comments
rIgDistNAl USI Start of run 0 or number of allocated entries in...
rIgDistN USI Start of run 0 or number of used entries in...
rIgDist RIGDISTP Start of run NULL or ptr to heap array of distrubution info for rad int gain originating in zone.
  • ZNR solar gain targeting and radiation exchange variables set at setup time for use at runtime
  • added re cavity absorptance, 1995
  • reworked re CSE radiant exchange, 2010
Name Type Variability Description/Comments
surfA DBL Start of run
  • total surface area in zone, ft2 (surfaces, doors, windows, ducts)
  • (includes exterior of C_EXCNDCH_ADJZN surfaces)
surfASlr DBL Start of run
  • total "short wave" surface area in zone, ft2
  • = opaque area that participates in solar gain distribution
  • = surfaces and doors but not windows and ducts
  • Note: ducts cannot receive solar gain as of 4-2012
ductA DBL Start of run
  • total duct surface area in zone, ft2 (included in zn_surfA)
  • (info only)
surfEpsLWAvg DBL Start of run area-weighted surface LW emissivity = SUM( surfArea * surfEpsLW) / zn_surfA
airRadXC1 DBL Start of run constants re zn_airRadXarea calc
airRadXC2 DBL Start of run
airRadXArea DBL Start of run
  • area of air "surface", ft2
  • participates in LW exchange network
FAir DBL Start of run air F "view factor" (constant during simulation)
airCxF DBL End of hour
  • air factor for zn_cxSh re LW exchange
  • = zn_airRadXarea * zn_FAir * sigmaSB, Btuh/R^4
airCx DBL End of subhour air contribution to zn_cxSh, Btuh/F
  • ZNR solar gain targeting runtime variables 2-95
  • #define OC 2 above // shades Open/Closed array dimension. subscripts: 0 = open, 1 = closed.
  • temporaries used during one hour's m-h solar calculations in cgsolar.cpp. m-h cuz inputs include [gtSMSO][gtsmso]/C, sfIn/ExAbs.
Name Type Variability Description/Comments
rmTrans[index] DBL Array [OC] End of monthly-hourly
  • area-weighted summed diffuse transmissivity of windows in zone,
  • shades open/closed, re adjRmAbs
rmAbs number End of monthly-hourly sum of area-weighted solar (SW) absorptivity for opaque room surfaces (dimensionless).
adjRmAbs[index] DBL Array [OC] End of monthly-hourly
  • rmAbs adjusted for reflected energy that goes out windows (m-h):
  • divisor in computing cavAbs's for [znCAir][zncair] and massive surfaces
rmAbsCAir DBL End of monthly-hourly sum of area-weighted absorptivity for non-massive room surfaces
cavAbsCAir[index] DBL Array [OC] End of monthly-hourly zone CAIR cavity absorptance === portion insolation to no particular surface
sgfCavBm[index] DBL Array [OC] End of monthly-hourly zone's solar gain factors from its windows not explicitly targeted for hour,
sgfCavDf[index] DBL Array [OC] End of monthly-hourly .. to be distributed amoung surface and CAir SgR entries after accumulation.
sgSaBm[index] DBL Array [OC] End of monthly-hourly CAIR adjustments to above for gains getting to other side of (quick) surface or
sgSaDf[index] DBL Array [OC] End of monthly-hourly .. lost to outdoors due to surface film vs conductance thru (quick) surface
sgfCAirBm[index] DBL Array [OC] End of monthly-hourly beam solar gain factor this hour to zone CAir
sgfCAirDf[index] DBL Array [OC] End of monthly-hourly diffuse .. These are multipliers for wthr data, later, via SgR

ZNR loads setup time variables: ua's (uval*area), used for zn_aqLdHr for 'a' for "Tz = (a + q)/b".

Name Type Variability Description/Comments
uaSpecT DBL Start of run light surface UA to specified temps (exCnd=specT surfaces), for zn_bcon, Btuh/F
ua DBL Start of run
  • light surface UA to ambient (sum uval*area), constant for run, for zn_bcon and zn_aqLdHr. Btuh/F.
  • Accumulation to double found nec for CEC custom budget *EXACT* match: float sometimes
  • gave 1 part in 100000 differences (CEC certification test calls for 2-digit match).
UANom DBL Start of run All-surface UA to ambient (sum of surface UNom derived with default surf conductances), Btuh/F
ductCondUANom DBL Start of run nominal total UA of ducts in zone, Btuh/F (due to conduction, not air leakage)
Name Type Variability Description/Comments
haMass DBL Start of run Total ha (surf conductance * area) to mass (Btuh/F)
  • re determination of below grade floor coefficients
  • floor coupling depends on wall insulation
  • walls processed first and accumulate here
Name Type Variability Description/Comments
BGWallPerim DBL Start of run total below grade wall perimeter, ft
BGWallPA4 DBL Start of run sum (perim*a4)
BGWallPA5 DBL Start of run sum (perim*a5)

ZNR loads runtime: hourly q's for Tz = (a + q)/b.

Name Type Variability Description/Comments
qSgTot number End of hour
  • hour total solar gain to zone, Btuh
  • = zn_sgTotTarg.st_tot
sgTotTarg
  • hourly part of s g total (Btuh) for zone: hourly mass insides.
  • Added to in cnloads.cpp:loadsHour via pointers in SgR entries made monthly
  • in cgsolar.cpp per info in XSURFs made in cncultn.cpp. Used: cnztu.cpp re results qSlr
  • radiant internal gain from [GAIN][gain] inputs. All POWER (Btuh). Next 4 set via rIgDist. 11-95.
SGTARG
Name Type Variability Description/Comments
sgTotTarg.bm DBL End of subhour beam
sgTotTarg.df DBL End of subhour diffuse
sgTotTarg.tot DBL End of subhour total
qrIgTot RIGTARG End of hour total originating in this zone: redundant total for energy balance check only.
qrIgTotO RIGTARG End of hour subtotal lost to outdoors thru light surfaces, to show in ZEB rpt as -Cond.
qrIgTotIz RIGTARG End of hour
  • net subtotal to other zones thru light surfaces, to show in ZEB rpt as -Izone.
  • energy balance: qrIgTot - qIgTotIz - qIgTotO = qrIgAir + qrIgMs
qrIgAir RIGTARG End of hour rad int gain to this zone's CAir (for light surfaces/windows), for zn_aqLdHr. 11-95.
qrIgMs number End of hour rad int gain to mass sides in this zone, for energy balance, set in cnLoads. 11-95.

e? next five contain prior hour's value at start hour expr time, new value by 2nd subhour. see note 1, 1-92. e's 11-95.

Name Type Variability Description/Comments
znSGain DBL End of hour
  • POWER
  • zn's hr's sens gain (Btuh), total from zn's [GAINs][gain], to qsIgHr.
  • set cnguts, used cnloads.
  • qsIgHr (just below) includes znSGain but excludes qrIgAir.
znLGain DBL End of hour
  • POWER
  • latent gain (Btuh), from ditto, used by ZNR::znW.
  • additional accumulators for lighting end use gains, re daylighting, for NREL. set cnguts, used cnztu.cpp. 9-94.
znLitDmd DBL End of hour
  • POWER
  • lighting demand (before reduction by [gnDlFrPow][gndlfrpow])
znLitEu DBL End of hour
  • POWER
  • lighting energy use (after reduction by [gnDlFrPow][gndlfrpow]; also posted to znS/LGain & meter).
Name Type Variability Description/Comments
znXLGain DBL End of subhour
  • POWER
  • excess latent gain (Btuh) rejected in znW() to prevent over-saturated w. 10-96.
znXLGainLs DBL End of subhour
  • POWER
  • previous subhour ditto: added to sensible gain to simulate condensation in zone, 5-97.

b's (sigma(UAi))

Name Type Variability Description/Comments
bcon DBL Start of run portion of b constant for run: ua + uaSpecT. setup time.

ZNR loads runtime: subhourly q's, a's, b's for Tz = (a + q)/b.

Name Type Variability Description/Comments
qMsSg DBL End of subhour
  • POWER
  • subhour's solar gain rate (Btuh) to mass surfaces in zn, to subtract from subhour results qMass.
  • note 2.
qSgAir DBL End of subhour subhour's solar gain rate (Btuh) to air
sgAirTarg
  • Solar gain (Btuh) target (float) for zone air: all sun thru windows not [SGDIST][sgdist]'d to a mass.
  • Added to in cnloads.cpp:loadsSubhr via pointers in SgR entries made monthly
  • in cgsolar.cpp per info in XSURFs made in cncultn.cpp. Used: cnloads.cpp re aqLdSh. */
SGTARG
Name Type Variability Description/Comments
sgAirTarg.bm DBL End of subhour beam
sgAirTarg.df DBL End of subhour diffuse
sgAirTarg.tot DBL End of subhour total
Name Type Variability Description/Comments
sgTotShTarg
  • subhourly part of s g total (Btuh) for zone: air + mass insides.
  • Added to in cnloads.cpp:loadsSubhr via pointers in SgR entries made monthly
  • in cgsolar.cpp per info in XSURFs made in cncultn.cpp. Used: cnztu.cpp re results qSlr */
SGTARG
Name Type Variability Description/Comments
sgTotShTarg.bm DBL End of subhour beam
sgTotShTarg.df DBL End of subhour diffuse
sgTotShTarg.tot DBL End of subhour total
qSgTotSh number End of subhour
  • Total solar gain to room, including transmitted and inward flowing fraction, Btuh
  • = zn_sgTotShTarg.st_tot + inward flowing from ASHWAT glazing
qIzXAnSh DBL End of subhour subhourly gain due to non-airnet IZXFERs (Btuh, +=into zone)
qIzSh DBL End of subhour
  • subhourly part of interzone gain rate (Btuh, +=into zone)
  • due to non-airnet [IZXFERs][izxfer]
  • subhourly values re airnet heat gains (see [IZXFER][izxfer])
  • [ 0]=minimum (generally infil only)
  • [ 1]=maximum (generally infil+vent)
Name Type Variability Description/Comments
pz0W[index] DBL Array [2] End of subhour
  • working zone pressures relative to patm at nominal z=0, lbf/sf
  • [ 0]=infil only; [ 1]=infil+ven
pz0WarnCount[index] number Array [2] End of run
  • # of unreasonable pressure warnings issued for this zone
  • [0]=infil only; [1]=infil+vent
Name Type Variability Description/Comments
pz0 DBL End of subhour
  • final zone pressure relative to patm at nominal z=0, lbf/sf
  • = zn_fVent-weighted avg of zn_pz0W[ 0] and zn_pz0W[ 1]
ventUt number End of subhour
  • vent utility for this substep
  • <0=bad (don't vent), 0=don't care, 1=maybe helpful
  • subhour zone gains from duct conduction losses, Btuh
  • (convective/radiant only)
  • CAUTION: subhr initialization not at beginning of step
  • re lagged values in zone balance
Name Type Variability Description/Comments
qDuctCondAir DBL End of subhour to ta (convection)
qDuctCondRad DBL End of subhour to tr (radiation)
qDuctCond DBL End of subhour sum FROM LAST STEP (else energy balance trouble)
  • subhour DHW zone transfers, Btuh
  • (convective/radiant only)
Name Type Variability Description/Comments
qDHWLossAir DBL End of subhour to ta (convection)
qDHWLossRad DBL End of subhour to tr (radiation)
qDHWLoss DBL End of subhour sum
qHPWH DBL End of subhour
  • heat extracted from zone by heat pump DHWHEATER(s)
  • assumed from ta (convective) (always <=0)
  • Included in zone balance as heat, not air flow,
  • else energy bal error possible
hpwhAirX number End of subhour
  • approximate zone air change rate due to
  • heat pump water heater source air (changes/hr)
  • air assumed returned to source zone
  • affects zn_hcFrc but not pressure balance
Name Type Variability Description/Comments
anVentEffect number End of hour
  • # of IZXRATs that could impact airnet
  • zone vent flow. Derived from ad_Ae/ad_mdotP,
  • ok whether zn_airNetI[ 1] is calc'd or not
airNetI[index] Array [2]
  • total *possible* airnet flow into zone
  • note actual flow depends of zn_fVent
  • [ 0]=infil only
  • [ 1]=infil+vent (calc'd only if needed)
AIRFLOW
Name Type Variability Description/Comments
airNetI[index].tdb DBL End of subhour air dry-bulb temp, F
airNetI[index].w DBL End of subhour air humidity ratio, lb moisture/lb dry air
Name Type Variability Description/Comments
airNetI[index].amf DBL End of subhour
  • mass flow rate, lb/hr dry air
  • *s *e DBL as_tdb // from AIRSTATE
  • *s *e DBL as_w
Name Type Variability Description/Comments
fVentPrf number End of subhour
  • preferred vent fraction for this zone in isolation
  • (not limited by e.g. C_VENTAVAILVC_WHOLEBLDG)
tzVent number End of subhour
  • zone air temp with full vent, F (debug aid)
  • 0 if vent not possible
fVent number End of subhour
  • vent fraction actual; venting used to hold zone at zn_tzspD
  • = (actual mCp) / (possible mCp)
anAmfCpVent DBL End of subhour vent flow (in excess of zn_airNetI[ 0]), Btuh/F
anAmfCpTVent DBL End of subhour vent flow*temp (in excess of zn_airNetI[ 0]), Btuh
  • total HVAC-related air flows for step
  • includes run fract (i.e. =0 when system off)
Name Type Variability Description/Comments
ductLkI duct leak into zone
AIRFLOW
Name Type Variability Description/Comments
ductLkI.tdb DBL End of subhour air dry-bulb temp, F
ductLkI.w DBL End of subhour air humidity ratio, lb moisture/lb dry air
Name Type Variability Description/Comments
ductLkI.amf DBL End of subhour
  • mass flow rate, lb/hr dry air
  • *s *e DBL as_tdb // from AIRSTATE
  • *s *e DBL as_w
ductLkO duct leak out of zone
AIRFLOW
Name Type Variability Description/Comments
ductLkO.tdb DBL End of subhour air dry-bulb temp, F
ductLkO.w DBL End of subhour air humidity ratio, lb moisture/lb dry air
Name Type Variability Description/Comments
ductLkO.amf DBL End of subhour
  • mass flow rate, lb/hr dry air
  • *s *e DBL as_tdb // from AIRSTATE
  • *s *e DBL as_w
sysAirI HVAC air into zone (supply)
AIRFLOW
Name Type Variability Description/Comments
sysAirI.tdb DBL End of subhour air dry-bulb temp, F
sysAirI.w DBL End of subhour air humidity ratio, lb moisture/lb dry air
Name Type Variability Description/Comments
sysAirI.amf DBL End of subhour
  • mass flow rate, lb/hr dry air
  • *s *e DBL as_tdb // from AIRSTATE
  • *s *e DBL as_w
sysAirO HVAC air out of zone (return)
AIRFLOW
Name Type Variability Description/Comments
sysAirO.tdb DBL End of subhour air dry-bulb temp, F
sysAirO.w DBL End of subhour air humidity ratio, lb moisture/lb dry air
Name Type Variability Description/Comments
sysAirO.amf DBL End of subhour
  • mass flow rate, lb/hr dry air
  • *s *e DBL as_tdb // from AIRSTATE
  • *s *e DBL as_w
OAVRlfO
  • HVAC OAV air out
  • in OAV mode, zn_sysAirO = 0 and zn_OAVRlfO > 0
AIRFLOW
Name Type Variability Description/Comments
OAVRlfO.tdb DBL End of subhour air dry-bulb temp, F
OAVRlfO.w DBL End of subhour air humidity ratio, lb moisture/lb dry air
Name Type Variability Description/Comments
OAVRlfO.amf DBL End of subhour
  • mass flow rate, lb/hr dry air
  • *s *e DBL as_tdb // from AIRSTATE
  • *s *e DBL as_w
Name Type Variability Description/Comments
sysDepAirIls
  • total system dependant flow into zone from prior step
  • = zn_ductLkI
  • lagged value used in zone HB re duct leaks, etc.
  • that depend on HVAC performance.
  • * does NOT include zn_sysAirI
  • * NOT used in mass balance
AIRFLOW
Name Type Variability Description/Comments
sysDepAirIls.tdb DBL End of subhour air dry-bulb temp, F
sysDepAirIls.w DBL End of subhour air humidity ratio, lb moisture/lb dry air
Name Type Variability Description/Comments
sysDepAirIls.amf DBL End of subhour
  • mass flow rate, lb/hr dry air
  • *s *e DBL as_tdb // from AIRSTATE
  • *s *e DBL as_w
Name Type Variability Description/Comments
qCondQS DBL End of subhour total quick surface conduction, Btuh (+ = into zone)
qCondMS DBL End of subhour
  • total mass exterior surface conduction, Btuh (+ = into zone)
  • computed/unused 12-21-10
rsAmfSysReq[index] DBL Array [2] End of subhour
  • requested [RSYS][rsys] air mass flow (at system) to hold current step set point, lbm/hr
  • [ 0]=with main source
  • [ 1]=with main+aux (ASHP only)
rsFSize number End of subhour fraction of requested air that RSYS could provide
rsAmfSup DBL End of subhour final RSYS supply air mass flow (at register, +=in), lbm/hr
rsAmfRet DBL End of subhour final RSYS return air mass flow (out of zone at grille, +=out), lbm/hr
rsAmfRetLs DBL Start of subhour last step zn_rsAmfRet (+ = out)
Name Type Variability Description/Comments
tzsp TEMP_GZ End of subhour
  • current step controlling set point, F
  • may not be reliably set for all modes
  • 0 if no active setpoint
tzspH TEMP_GZ End of subhour current step heating set point, F
tzspD TEMP_GZ End of subhour current step desired temp set point, F
tzspC TEMP_GZ End of subhour current step cooling set point, F
Name Type Variability Description/Comments
tzspHlh TEMP_GZ Start of hour end-of-last-hour heating set point (re autosize setpoint ramping), F
tzspDlh TEMP_GZ Start of hour end-of-last-hour desired temp set point (re autosize setpoint ramping), F
tzspClh TEMP_GZ Start of hour end-of-last-hour cooling set point (re autosize setpoint ramping), F
Name Type Variability Description/Comments
hcMode number End of subhour
  • heating / cooling mode required per set point (rsmHEAT, rsmCOOL, )
  • (may not match [RSYS][rsys].rs_mode due to e.g. [RSYS][rsys] availability or
  • conflicting zone requests)

HVAC convective delivery fraction (TODO: now all 1, 6-2012)

Name Type Variability Description/Comments
fConvH number Start of subhour heating
fConvC number Start of subhour cooling
fConv number Start of subhour current step
Name Type Variability Description/Comments
qsHvac DBL End of subhour
  • subhour total (sensible) power of all hvac, Btuh
  • NB: power (Btuh) q is *subhrDur'd to yield energy (Btu) q's for results.
qlHvac DBL End of subhour subhour total latent power (Btuh) (moisture * 1061) likewise
qlIz DBL End of subhour
  • latent gain from [IZXFER][izxfer] sources (infil, vent, and duct leakage), Btuh
  • does NOT include HVAC
rho DBL End of subhour zone moist air density at nominal w=tp_refW, lb/cf
rho0ls DBL Start of subhour prior step zone moist air density at nominal z=0, lb/cf; computed from tzls and zn_pz0[ 0]
dryAirMass DBL End of subhour total mass of *dry* air in zone, lbm
dryAirMassEff DBL End of subhour
  • effective dry air mass in zone, lbm
  • = zn_dryAirMass*i.zn_HIRatio except when zone moisture time constant
  • requires increase for numerical stability
  • See zn_AirXMoistureBal()
ivAirX number End of subhour
  • zone infiltration/ventilation air change rate (changes/hr)
  • includes flow induced by system (HVAC, duct leakage, )
  • but not system flows
airX number End of subhour
  • overall zone air change rate (changes/hr)
  • includes *all* air flows; used re convective coeff determination
  • *s *e FLOAT i.zn_hcAirX // zn_airX + add'l 4.8 ACH for non-air zones having HVAC loads, changes/hr
  • inputable for testing; used re convection coeff model
Name Type Variability Description/Comments
hcAirXls number Start of subhour prior subhour value of i.zn_hcAirX, change/hr
hcAirXComb number End of subhour
  • combined zone air change rate for this subhour, changes/hr
  • = zn_hcAirXls + zn_hpwhAirX
hcFrc number End of subhour inside surface forced convection coefficient, Btuh/ft2-F
windPresV number Start of subhour
  • wind velocity pressure, lbf/ft2
  • zone-specific per zn_EaveZ and zn_infShield

ZNR runtime zone temps and w's

Name Type Variability Description/Comments
tz DBL End of subhour
  • TEMP
  • zone air temp: official copy for results: active setpoint or floating
aTz DBL End of subhour
  • TEMP
  • air handler working copy of tz, possibly abandoned if change very small.
wz DBL End of subhour
  • HUMRAT
  • zone humidity ratio (w)
relHum number End of subhour zone relative humidity, 0 - 1
relHumls number Start of subhour zone relative humidity, end last subhour, 0 - 1
relHumlh number Start of hour zone relative humidity, end last hour, 0 - 1
twb DBL End of subhour zone wet bulb temp, F
aWz DBL End of subhour
  • HUMRAT
  • air handler working copy of wz, possibly abandoned if change very small.
tzls DBL Start of subhour
  • TEMP
  • zone temp, end last subhour, F
wzls DBL Start of subhour
  • HUMRAT
  • zone hum rat, end last subhour (same as wz in 1st iteration of subhr)
tzlh DBL Start of hour
  • TEMP
  • zone temp, end last hour
tzlsDelta DBL Unknown
  • TEMPDIFF
  • zone temp change during last subhour: tzls - tz at end subhour
wzlsDelta DBL Unknown
  • HUMRAT
  • zone hum rat change during last subhour: wzls - wz at end subhour

re radiant/convective model

Name Type Variability Description/Comments
tr DBL End of subhour
  • TEMP
  • zone radiant temp, F
trls DBL End of subhour
  • TEMP
  • zone radiant temp, end last subhour, F
trlh DBL Start of hour
  • TEMP
  • zone radiant temp, end last hour, F

ZNR runtime hvac internal, mostly sub or hourly

Name Type Variability Description/Comments
md number End of subhour current hvac mode: subscript of mdSeq