4.25 RSYS
RSYS constructs an object representing an air-based residential HVAC system.
rsName
Optional name of HVAC system; give after the word “RSYS” if desired.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| 63 characters | none | No | constant |
rsType=choice
Type of system.
| rsType | Description |
|---|---|
| ACFURNACE | Compressor-based cooling modeled per SEER and EER. Fuel-fired heating. Primary heating input energy is accumulated to end use HTG of meter rsFuelMtr. |
| ACPMFURNACE | Compressor-based cooling modeled per PERFORMANCEMAP specified in rsPerfMapClg. Fuel-fired heating. Primary heating input energy is accumulated to end use HTG of meter rsFuelMtr. |
| ACRESISTANCE | Compressor-based cooling and electric (‘strip’) heating. Cooling performance based on SEER and EER. Primary heating input energy is accumulated to end use HTG of meter rsElecMtr. |
| ACPMRESISTANCE | Cooling based on PERFORMANCEMAP specified in rsPerfMapClg. Primary heating input energy is accumulated to end use HTG of meter rsElecMtr. |
| ASHP | Air-source heat pump (compressor-based heating and cooling). Primary (compressor) heating input energy is accumulated to end use HTG of meter rsElecMtr. Auxiliary and defrost heating input energy is accumulated to end use HPBU of meter rsElecMtr or meter rsFuelMtr (depending on rsTypeAuxH). |
| ASHPKGROOM | Packaged room air-source heat pump. |
| ASHPHYDRONIC | Air-to-water heat pump with hydronic distribution. Compressor performance is approximated using the air-to-air model with adjusted efficiencies. |
| ASHPPM | Air-to-air heat pump modeled per PERFORMANCMAPs specified via rsPerfMapHtg and rsPerfMapClg. |
| WSHP | Water-to-air heat pump. |
| AC | Compressor-based cooling; no heating. Required ratings are SEER and capacity and EER at 95 oF outdoor dry bulb. |
| ACPM | Compressor-based cooling modeled per PERFORMANCEMAP specified in rsPerfMapClg; no heating. |
| ACPKGROOM | Packaged compressor-based cooling; no heating. Required ratings are capacity and EER at 95 oF outdoor dry bulb. |
| FURNACE | Fuel-fired heating. Primary heating input energy is accumulated to end use HTG of meter rsFuelMtr. |
| RESISTANCE | Electric heating. Primary heating input energy is accumulated to end use HTG of meter rsElecMtr. |
| ACPKGROOMFURNACE | Packaged room cooling and (separate) furnace heating. |
| ACPKGROOMRESISTANCE | Packaged room cooling and electric resistance heating. |
| COMBINEDHEATDHW | Combined heating / DHW. Use rsCHDHWSYS to specify the DHWSYS that provides hot water to the coil in this RSYS. No cooling. |
| ACCOMBINEDHEATDHW | Compressor-based cooling; COMBINEDHEATDHW heating. |
| ACPMCOMBINEDHEATDHW | Compressor-based cooling modeled per PERFORMANCEMAP specified in rsPerfMapClg; COMBINEDHEATDHW heating. |
| FANCOIL | Coil-based heating and cooling. No primary (fuel-using) equipment is modeled. rsLoadMtr, rsHtgLoadMtr, and rsClgLoadMtr are typically used to record loads for linking to an external model. |
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| one of above choices | ACFURNACE | No | constant |
rsDesc=string
Text description of system, included as documentation in debugging reports such as those triggered by rsGeneratePerfMap=YES
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| string | none | No | constant |
rsModeCtrl=choice
Specifies systems heating/cooling availability during simulation.
| OFF | System is off (neither heating nor cooling is available) |
| HEAT | System can heat (assuming rsType can heat) |
| COOL | System can cool (assuming rsType can cool) |
| AUTO | System can either heat or cool (assuming rsType compatibility). First request by any zone served by this RSYS determines mode for the current time step. |
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| OFF, HEAT, COOL, AUTO | AUTO | No | hourly |
rsGeneratePerfMap=choice
Generate performance map(s) for this RSYS. Comma-separated text is written to file PM_[rsName].csv. This is a debugging capability that is not necessarily maintained. The format of the generated csv text file may change and is unrelated to the PERFORMANCEMAP input scheme used via rsPerfMapHtg and rsPerfMapClg.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| YES, NO | NO | No | constant |
rsFanTy=choice
Specifies fan (blower) position relative to primary heating or cooling source (i.e. heat exchanger or heat pump coil for heating and AC coil for cooling). The blower position determines where fan heat is added to the RSYS air stream and thus influences the coil entering air temperature.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| BLOWTHRU, DRAWTHRU | BLOWTHRU | No | constant |
rsFanMotTy=choice
Specifies type of motor driving the fan (blower). This is used in the derivation of the coil-only cooling capacity for the RSYS.
| PSC | Permanent split capacitor |
| BPM | Brushless permanent magnet (aka ECM) |
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| PSC, BPM | PSC | No | constant |
rsAdjForFanHt=choice
Fan heat adjustment with two options Yes or no. Yes: fanHtRtd derived from rsFanTy and removed from capacity and input values. No: no rated fan heat adjustments.
rsElecMtr=mtrName
Name of METER object, if any, by which system’s electrical energy use is recorded (under appropriate end uses).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| name of a METER | none | No | constant |
rsFuelMtr =mtrName
Name of METER object, if any, by which system’s fuel energy use is recorded (under appropriate end uses).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| name of a METER | none | No | constant |
rsLoadMtr =ldMtrName
rsHtgLoadMtr =ldMtrName
rsClgLoadMtr =ldMtrName
Names of LOADMETER objects, if any, to which the system’s heating and/or cooling loads are recorded. Loads are the gross heating and cooling energy added to (or removed from) the air stream. Fan heat, auxiliary heat, and duct losses are not included in loads values.
rsLoadMtr accumulates both heating (> 0) and cooling (< 0) loads. rsHtgLoadMtr accumulates only heating loads. rsClgLoadMtr accumulates only cooling loads. This arrangement accomodates mixed heating and cooling source configurations. For example, loads can be tracked appropriately in a building that has multiple cooling sources and a single heating source.
rsLoadMtr should not specify the same LOADMETER as rsHtgLoadMtr or rsClgLoadMtr since this would result in double counting.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| name of a LOADMETER | none | No | constant |
rsSrcSideLoadMtr=ldMtrName
rsHtgSrcSideLoadMtr =ldMtrName
rsClgSrcSideLoadMtr =ldMtrName
Name of LOADMETER objects, if any, to which the system’s source-side heat transfers are recorded. For DX systems, this is the outdoor coil heat transfer. For other types, source-side values are the same as the indoor coil loads reported via rsLoadMtr.
rsSrcSideLoadMtr accumulates both heating (> 0) and cooling (< 0) transfers. rsHtgSrcSideLoadMtr accumulates only heating transfers. rsClgSrcSideLoadMtr accumulates only cooling transfers. This arrangement accomodates mixed heating and cooling source configurations.
rsSrcSideLoadMtr should not specify the same LOADMETER as rsHtgSrcSideLoadMtr or rsClgSrcSideLoadMtr since this would result in double counting.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Name of a LOADMETER | No | constant |
rsCHDHWSYS=dhwsysName
DHWSYS hot water source for this RSYS, required when rsType is COMBINEDHEATDHW or ACCOMBINEDHEATDHW. The specified DHWSYS must include a DHWHEATER of whType=ASHPX or RESISTANCEX.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Name of a DHWSYS | none | if combined heat/DHW | constant |
rsAFUE=float
Heating Annual Fuel Utilization Efficiency (AFUE).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| 0 \(<\) x \(\le\) 1 | 0.9 if furnace, 1.0 if resistance | No | constant |
rsCapH=float
Heating capacity, used when rsType is ACFURNACE, ACRESISTANCE, FURNACE, WSHP or RESISTANCE.
If rsType=WSHP, rsCapH is at source fluid temperature = 68 oF.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/hr | AUTOSIZE or x \(\ge\) 0 | 0 | No | constant |
rsTdDesH=float
Nominal heating temperature rise (across system, not at zone) used during autosizing (when capacity is not yet known) and to derive heating air flow rate from heating capacity.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| oF | x \(>\) 0 | 30 oF if heat pump else 50 oF | No | constant |
rsFxCapH=float
Heating autosizing capacity factor. If AUTOSIZEd, rsCapH or rsCap47 is set to rsFxCapH \(\times\) (peak design-day load). Peak design-day load is the heating capacity that holds zone temperature at the thermostat set point during the last substep of all hours of all design days.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 1.4 | No | constant |
rsFanPwrH=float
Heating operating fan power. For most rsTypes, heating air flow is calculated from heating capacity and rsTdDesH. The default value of rsFanPwrH is .365 W/cfm except 0.273 W/cfm is used when rsType=COMBINEDHEATDHW and rsType=ACCOMBINEDHEATDHW.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| W/cfm | x \(\ge\) 0 | see above | No | constant |
rsHSPF=float
For rsType=ASHP, Heating Seasonal Performance Factor (HSPF).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/Wh | x \(>\) 0 | none | Yes if rsType=ASHP | constant |
rsCap47=float
For rsType=ASHP, rated heating capacity at outdoor dry-bulb temperature = 47 oF.
If rsType=ASHP and both rsCapC and rsCap47 are autosized, both are set to the larger consistent value using rsCapRat9547 (after application of rsFxCapH and rsFxCapC).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/Wh | AUTOSIZE or x \(>\) 0 | Calculated from rsCapC | No | constant |
rsCap35=float
For rsType=ASHP, rated heating capacity at outdoor dry-bulb temperature = 35 oF. rsCap35 typically reflects reduced capacity due to reverse (cooling) heat pump operation for defrost.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/Wh | x \(>\) 0 | Calculated from rsCap47 and rsCap17 | No | constant |
rsCap17=float
For rsType=ASHP, rated heating capacity at outdoor dry-bulb temperature = 17 oF.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/Wh | x \(>\) 0 | Calculated from rsCap47 | No | constant |
rsCOP95=float
For rsType=ASHP, rated heating coefficient of performance at outdoor dry-bulb temperature = 95 oF.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | Calculated from rsCap95 | No | constant |
rsCOP47=float
For rsType=ASHP, rated heating coefficient of performance at outdoor dry-bulb temperature = 47 oF. For rsType=WSHP, rated heating coefficient of performance at source fluid temperature = 68 oF.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | Estimated from rsHSPF, rsCap47, and rsCap17 | No | constant |
rsCOP35=float
For rsType=ASHP, rated heating coefficient of performance at outdoor dry-bulb temperature = 35 oF.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | Calculated from rsCap35, rsCap47, rsCap17, rsCOP47, and rsCOP17 | No | constant |
rsCOP17=float
For rsType=ASHP, rated heating coefficient of performance at outdoor dry-bulb temperature = 17 oF.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | Calculated from rsHSPF, rsCap47, and rsCap17 | No | constant |
rsCapRat1747=float
Ratio of rsCAP17 over rsCAP47.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | Based on HSPF or other correlations | No | Start of a run |
rsCapRat9547=float
Ratio of rsCAP95 to rsCAP47. This ratio is used for inter-defaulting rsCap47 and rsCapC such that they have consistent values as is required given that a heat pump is a single device. If not given, rsCapRat9547 is determined during calculations using the relationship cap95 = 0.98 * cap47 + 180 (derived via correlation of capacities of a set of real units).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | See above | No | constant |
rsCapRatCH=float
For WSHP only: ratio of rsCapC to rsCapH. Used to derive capacity during autosizing or when only one capacity is specified.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| .3 \(\leq\) x \(<\) 2 | 0.8 | No | Start of a run |
rsPerfMapHtg=performanceMapName
Specifies the heating performance PERFORMANCEMAP for RSYSs having rsType=ASHPPM. The PERFORMANCEMAP must have grid variables outdoor drybulb and compressor speed (in that order) and lookup values of net capacity ratios and COP. See example in PERFORMANCEMAP.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Name of a PERFORMANCEMAP | if rsType specifies a performance map model | Start of a run |
rsPerfMapClg=performanceMapName
Specifies the cooling performance PERFORMANCEMAP for RSYSs having rsType=ASHPPM, ACPM, ACPMFURNACE, ACPMRESISTANCE, or ACPMCOMBINEDHEATDHW. The PERFORMANCEMAP must have grid variables outdoor drybulb and compressor speed (in that order) and lookup values of net capacity ratios and COP. See example in PERFORMANCEMAP.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Name of a PERFORMANCEMAP | if rsType specifies a performance map model | Start of a run |
rsTypeAuxH=choice
For rsType=ASHP, type of auxiliary heat. Auxiliary heating is used when heatpump capacity is insufficient to maintain zone temperature and during reverse-cycle defrost operation (if rsDefrostModel=REVCYCLEAUX). If rsTypeAuxH=Furnace, energy use for auxiliary heat is accumulated to end use HPBU of meter rsFuelMtr (if specified). If rsTypeAuxH=Resistance, energy use for auxiliary heat is accumulated to end use HPBU of meter rsElecMtr (if specified).
| Choice | Description |
|---|---|
| NONE | No auxiliary heat |
| RESISTANCE | Electric resistance (aka strip heat) |
| FURNACE | Fuel-fired |
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| See table above | RESISTANCE | No | constant |
rsCtrlAuxH=choice
For rsType=ASHP, type of auxiliary heating control.
| Choice | Description |
|---|---|
| LOCKOUT | Compressor locked out if any auxiliary heating control |
| CYCLE | Compressor runs continuously and auxiliary cycles |
| ALTERNATE | Alternates between compressor and auxiliary |
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| See table above | ALTERNATE if rsTypeAuxH=FURNACE else CYCLE | No | Start of a run |
rsCapAuxH=float
For rsType=ASHP, auxiliary heating capacity. If AUTOSIZEd, rsCapAuxH is set to the peak heating load evaluated at the heating design temperature (Top.heatDsTDbO).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/hr | AUTOSIZE or x \(\ge\) 0 | 0 | No | constant |
rsAFUEAuxH=float
For rsType=ASHP, auxiliary heat annualized fuel utilization efficiency.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 0.9 if rsTypeAuxH=FURNACE else 1 | No | constant |
rsDefrostModel=choice
Selects modeling options for ASHP outdoor coil defrosting when 17 oF < TDbO < 45 oF. In this temperature range, heating capacity and/or efficiency are typically reduced due to frost accumulation on the outdoor coil.
| NONE | Defrost is not modeled. When 17 oF < TDbO < 45 oF, capacity and efficiency are determined by interpolation using unmodified 17 oF and 47 oF data. |
| REVCYCLE | Reverse compressor (cooling) operation. Net capacity and efficiency is derived from rsCap17/rsCOP17 and rsCap35/rsCOP35 using linear interpolation. Auxiliary heat is not modeled. |
| REVCYCLEAUX | Reverse compressor (cooling) operation with provision of sufficient auxiliary heat to make up the loss of heating capacity. Auxiliary heating is typically used to prevent cold air delivery to zones during the defrost cycle. |
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| one of above choices | REVCYCLEAUX | No | constant |
rsSHRtarget=float
Nominal target for sensible heat ratio (for fancoil).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 0.7 | No | subhour |
rsFxCapAuxH=float
Auxiliary heating autosizing capacity factor. If AUTOSIZEd, rsCapAuxH is set to rsFxCapAuxH \(\times\) (peak design-day load). Peak design-day load is the heating capacity that holds zone temperature at the thermostat set point during the last substep of all hours of all design days.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 1 | No | constant |
rsSEER=float
Cooling rated Seasonal Energy Efficiency Ratio (SEER).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/Wh | x \(>\) 0 | none | Yes | constant |
rsEER=float
Cooling Energy Efficiency Ratio (EER) at standard AHRI rating conditions (outdoor drybulb of 95 oF and entering air at 80 oF drybulb and 67 oF wetbulb). For rsType=WSHP, rated EER at fluid source temperature = 86 oF.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/Wh | x \(>\) 0 | Estimated from SEER unless WSHP | Yes for WSHP else No | constant |
rsCapC=float
Net cooling capacity at standard rating conditions (outdoor drybulb temperature = 95 oF for air source or fluid source temperature = 86 oF for water source).
If rsType=ASHP and both rsCapC and rsCap47 are autosized, both are set to the larger consistent value using rsCapRat9547 (after application of rsFxCapH and rsFxCapC).
If rsType=WSHP and both rsCapC and rsCapH are autosized, both are set to the larger consistent value using rsCapRatCH (after application of rsFxCapH and rsFxCapC).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/hr | AUTOSIZE or x \(\le\) 0 (x \(>\) 0 coverted to \(<\) 0) | none | Yes if rsType includes cooling | constant |
rsTdDesC=float
Nominal cooling temperature fall (across system, not zone) used during autosizing (when capacity is not yet known).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| oF | x \(<\) 0 | -25 | No | constant |
rsFxCapC=float
Cooling autosizing capacity factor. rsCapC is set to rsFxCapC \(\times\) (peak design-day load). Peak design-day load is the cooling capacity that holds zone temperature at the thermostat set point during the last substep of all hours of all design days.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 1.4 | No | constant |
rsFChg=float
Cooling compressor capacity factor. The gross cooling capacity is adjusted by the factor rsFChg as specified by California Title 24 procedures.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 1 (no effect) | No | constant |
rsVFPerTon=float
Standard air volumetric flow rate per nominal ton of cooling capacity.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| cfm/ton | 150 \(\le\) x \(\le\) 500 | 350 | No | constant |
rsFanPwrC=float
Cooling fan power.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| W/cfm | x \(\ge\) 0 | 0.365 | No | constant |
rsASHPLockOutT=float
Source air dry-bulb temperature below which the air source heat pump compressor does not operate.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| oF | (no lockout) | No | hourly |
rsCdH=float
Heating cyclic degradation coefficient, valid only for compressor-based heating (heat pumps).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| 0 \(\le\) x \(\le\) 0.5 | ASHPHYDRONIC: 0.25 ASHP: derived from rsHSPF | No | hourly |
rsCdC=float
Cooling cyclic degradation coefficient, valid for configurations having compressor-based cooling.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| 0 \(\le\) x \(\le\) 0.5 | 0 | No | hourly |
rsFEffH=float
Heating efficiency factor. At each time step, the heating efficiency is multiplied by rsFEffH.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 1 | No | subhourly |
rsFEffAuxHBackup=float
Backup auxiliary heating efficiency factor. At each time step, the backup heating efficiency is multiplied by rsFEffAuxHBackup. Backup auxiliary heating is typically provided by electric resistance “strip heat” but may be provided by a furnace (see rsTypeAuxH). If rsTypeAuxH is not “none”, backup heat operates when air source heat pump compressor capacity is insufficient to meet heating load. See also rsFEffAuxHDefrost.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 1 | No | subhourly |
rsFEffAuxHDefrost=float
Defrost auxiliary heating efficiency factor. At each time step, the defrost auxiliary heating efficiency is multiplied by rsFEffAuxHDefrost. Defrost auxiliary heating is typically provided by electric resistance “strip heat” but may be provided by a furnace (see rsTypeAuxH). If rsDefrostModel=REVCYCLEAUX, defrost auxiliary heat operates during air source heat pump defrost mode. Since defrost and backup heating are generally provided by the same equipment, rsFEffAuxHDefrost and rsFEffAuxHBackup are usually set to the same value, but separate inputs are available for special cases.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 1 | No | subhourly |
rsFEffC=float
Cooling efficiency factor. At each time step, the cooling efficiency is multiplied by rsEffC.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(>\) 0 | 1 | No | subhourly |
rsCapNomH=float
Heating nominal capacity. Provides type-independent probe source for RSYS heating capacity. Daily variability is specified to support value changes during AUTOSIZEing. Values set via input are typically constant.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/hr | x \(\ge\) 0 | no heating: 0 heat pump: rsCap47 (input or AUTOSIZEd) other: rsCapH (input or AUTOSIZEd) | No | daily |
rsCapNomC=float
Cooling nominal capacity. Provides type-independent probe source for RSYS cooling capacity. Daily variability is specified to support value changes during AUTOSIZEing. Values set via input are typically constant.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btu/hr | x \(\ge\) 0 | no cooling: 0 other: rsCap95 (input or AUTOSIZEd) | No | daily |
rsDSEH=float
Heating distribution system efficiency. If given, (1-rsDSEH) of RSYS heating output is discarded. Cannot be combined with more detailed DUCTSEG model.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| 0 < x < 1 | (use DUCTSEG model) | No | hourly |
rsDSEC=float
Cooling distribution system efficiency. If given, (1-rsDSEC) of RSYS cooling output is discarded. Cannot be combined with more detailed DUCTSEG model.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| 0 < x < 1 | (use DUCTSEG model) | No | hourly |
rsOAVType=choice
Type of central fan integrated (CFI) outside air ventilation (OAV) included in this RSYS. OAV systems use the central system fan to circulate outdoor air (e.g. for night ventilation).
OAV cannot operate simultaneously with whole building ventilation (operable windows, whole house fans, etc.). Availability of ventilation modes is controlled on an hourly basis via Top ventAvail.
| NONE | No CFI ventilation capabilities |
| FIXED | Fixed-flow CFI (aka SmartVent). The specified rsOAVVfDs is used whenever the RSYS operates in OAV mode. |
| VARIABLE | Variable-flow CFI (aka NightBreeze). Flow rate is determined at midnight based on prior day’s average dry-bulb temperature according to a control algorithm defined by the NightBreeze vendor. |
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| NONE, FIXED, VARIABLE | none | No | constant |
rsOAVVfDs=float
Design air volume flow rate when RSYS is operating in OAV mode.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| cfm | x \(\ge\) 0 | none | if rsOAVType $ e$ NONE | constant |
rsOAVVfMinF=float
Minimum air volume flow rate fraction when RSYS is operating in OAV mode. When rsOAVType=VARIABLE, air flow rate is constrained to rsOAVVfMinF * rsOAVVfDs or greater.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| 0 \(\le\) x \(\le\) 1 | 0.2 | No | constant |
rsOAVFanPwr=float
RSYS OAV-mode fan power.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| W/cfm | 0 < x \(\le\) 5 | per rsOAVTYPE FIXED: rsFanPwrC VARIABLE: NightBreeze vendor curve based on rsOAVvfDs | No | constant |
rsOAVTDbInlet=float
OAV inlet (source) air temperature. Supply air temperature at the zone is generally higher due to fan heat. Duct losses, if any, also alter the supply air temperature.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| oF | x \(\ge\) 0 | Dry-bulb temperature from weather file | No | hourly |
rsOAVTdiff=float
OAV temperature differential. When operating in OAV mode, the zone set point temperature is max( znTD, inletT+rsOAVTdiff). Small values can result in inadvertent zone heating, due to fan heat.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| oF | x \(>\) 0 | 5 oF | No | hourly |
rsOAVReliefZn=znName
Name of zone to which relief air is directed during RSYS OAV operation, typically an attic zone. Relief air flow is included in the target zone’s pressure and thermal balance.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| name of ZONE | none | if rsOAVType $ e$ NONE | constant |
rsParElec=float
Parasitic electrical power. rsParElec is unconditionally accumulated to end use AUX of rsElecMtr (if specified) and has no other effect.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| W | 0 | No | hourly |
rsParFuel=float
Parasitic fuel use. rsParFuel is unconditionally accumulated to end use AUX of sFuelMtr (if specified) and has no other effect.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btuh | 0 | No | hourly |
rsRhIn=float
Entering air relative humidity (for model testing).
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| W/cfm | 0 \(\le\) x \(\le\) 1 | Derived from entering air state | No | constant |
rsTdbOut=float
Air dry-bulb temperature at the outdoor portion of this system.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| oF | x \(\ge\) 0 | From weather file | No | hourly |
endRSYS
Optionally indicates the end of the RSYS definition.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| none | No | constant |
Related Probes: