I have an IDF file where I changed the cooling and heating thermostat setpoints and now I'm getting this warning.
SizeDXCoil: Potential issue with equipment sizing for Coil:Cooling:DX:MultiSpeed COOLING COIL
User-Specified Speed 1 Rated Air Flow Rate [m3/s] = 0.49829
differs from Design Size Speed 1 Rated Air Flow Rate [m3/s] = 0.37600
This may, or may not, indicate mismatched component sizes.
Verify that the value entered is intended and is consistent with other components.
Plus a bunch of these warnings.
SimHVAC: Maximum iterations (20) exceeded for all HVAC loops
All of my values are hardcoded in the IDF as far as I know, and I haven't been able to find any object fields that would calculate this value for the simulation. I pasted the relevant IDF objects as text below. In case you need the whole IDF file, here is a google drive link. (The IDF objects are a little weird since we're trying to verify some experimental data matches our EnergyPlus simulation data by replicating all the environment and zone conditions and comparing the experimental to simulation data.)
How do I prevent the Design Size Speed 1 Rated Air Flow Rate [m3/s] from being calculated?
!- =========== ALL OBJECTS IN CLASS: VERSION ===========
Version,
9.1; !- Version Identifier
!- =========== ALL OBJECTS IN CLASS: SIMULATIONCONTROL ===========
SimulationControl,
No, !- Do Zone Sizing Calculation
No, !- Do System Sizing Calculation
No, !- Do Plant Sizing Calculation
No, !- Run Simulation for Sizing Periods
Yes, !- Run Simulation for Weather File Run Periods
No, !- Do HVAC Sizing Simulation for Sizing Periods
1; !- Maximum Number of HVAC Sizing Simulation Passes
!- =========== ALL OBJECTS IN CLASS: AIRTERMINAL:SINGLEDUCT:UNCONTROLLED ===========
AirTerminal:SingleDuct:Uncontrolled,
Air Terminal Single Duct Uncontrolled 1, !- Name
, !- Availability Schedule Name
Node 6, !- Zone Supply Air Node Name
0.752; !- Maximum Air Flow Rate {m3/s}
!- =========== ALL OBJECTS IN CLASS: FAN:SYSTEMMODEL ===========
Fan:SystemModel,
Fan, !- Name
School in Session Boolean, !- Availability Schedule Name
Mixed Air Node, !- Air Inlet Node Name
Fan Outlet, !- Air Outlet Node Name
0.752226608765, !- Design Maximum Air Flow Rate {m3/s}
Discrete, !- Speed Control Method
0.5, !- Electric Power Minimum Flow Rate Fraction
50, !- Design Pressure Rise {Pa}
0.9, !- Motor Efficiency
1, !- Motor In Air Stream Fraction
660, !- Design Electric Power Consumption {W}
, !- Design Power Sizing Method
, !- Electric Power Per Unit Flow Rate {W/(m3/s)}
, !- Electric Power Per Unit Flow Rate Per Unit Pressure {W/((m3/s)-Pa)}
0.7, !- Fan Total Efficiency
, !- Electric Power Function of Flow Fraction Curve Name
, !- Night Ventilation Mode Pressure Rise {Pa}
, !- Night Ventilation Mode Flow Fraction
, !- Motor Loss Zone Name
, !- Motor Loss Radiative Fraction
General, !- End-Use Subcategory
3, !- Number of Speeds
0.575797872, !- Speed 1 Flow Fraction
0.192424242, !- Speed 1 Electric Power Fraction
0.658244681, !- Speed 2 Flow Fraction
0.287878788, !- Speed 2 Electric Power Fraction
1, !- Speed 3 Flow Fraction
1; !- Speed 3 Electric Power Fraction
!- =========== ALL OBJECTS IN CLASS: COIL:COOLING:DX:MULTISPEED ===========
Coil:Cooling:DX:MultiSpeed,
Cooling Coil, !- Name
, !- Availability Schedule Name
Fan Outlet, !- Air Inlet Node Name
ClgCoil Outlet, !- Air Outlet Node Name
Condenser Inlet Node, !- Condenser Air Inlet Node Name
AirCooled, !- Condenser Type
-25, !- Minimum Outdoor Dry-Bulb Temperature for Compressor Operation {C}
, !- Supply Water Storage Tank Name
, !- Condensate Collection Water Storage Tank Name
No, !- Apply Part Load Fraction to Speeds Greater than 1
No, !- Apply Latent Degradation to Speeds Greater than 1
, !- Crankcase Heater Capacity {W}
10, !- Maximum Outdoor Dry-Bulb Temperature for Crankcase Heater Operation {C}
, !- Basin Heater Capacity {W/K}
, !- Basin Heater Setpoint Temperature {C}
, !- Basin Heater Operating Schedule Name
Electricity, !- Fuel Type
2, !- Number of Speeds
10961.28898, !- Speed 1 Gross Rated Total Cooling Capacity {W}
0.7, !- Speed 1 Gross Rated Sensible Heat Ratio
4.25328452245, !- Speed 1 Gross Rated Cooling COP {W/W}
0.498289495362, !- Speed 1 Rated Air Flow Rate {m3/s}
773.3, !- Speed 1 Rated Evaporator Fan Power Per Volume Flow Rate {W/(m3/s)}
Measured_C_Cap_FunctionOfTemp_LowSpeed, !- Speed 1 Total Cooling Capacity Function of Temperature Curve Name
Constant 1, !- Speed 1 Total Cooling Capacity Function of Flow Fraction Curve Name
Measured_C_EIR_FunctionOfTemp_LowSpeed, !- Speed 1 Energy Input Ratio Function of Temperature Curve Name
Constant 1, !- Speed 1 Energy Input Ratio Function of Flow Fraction Curve Name
Measured_HandC_PLC_Simple, !- Speed 1 Part Load Fraction Correlation Curve Name
, !- Speed 1 Nominal Time for Condensate Removal to Begin {s}
, !- Speed 1 Ratio of Initial Moisture Evaporation Rate and Steady State Latent Capacity {dimensionless}
, !- Speed 1 Maximum Cycling Rate {cycles/hr}
, !- Speed 1 Latent Capacity Time Constant {s}
, !- Speed 1 Rated Waste Heat Fraction of Power Input {dimensionless}
, !- Speed 1 Waste Heat Function of Temperature Curve Name
, !- Speed 1 Evaporative Condenser Effectiveness {dimensionless}
, !- Speed 1 Evaporative Condenser Air Flow Rate {m3/s}
, !- Speed 1 Rated Evaporative Condenser Pump Power Consumption {W}
16813.18398, !- Speed 2 Gross Rated Total Cooling Capacity {W}
0.7, !- Speed 2 Gross Rated Sensible Heat Ratio
4.31319252971, !- Speed 2 Gross Rated Cooling COP {W/W}
0.752, !- Speed 2 Rated Air Flow Rate {m3/s}
, !- Speed 2 Rated Evaporator Fan Power Per Volume Flow Rate {W/(m3/s)}
Measured_C_Cap_FunctionOfTemp_HighSpeed, !- Speed 2 Total Cooling Capacity Function of Temperature Curve Name
Constant 1, !- Speed 2 Total Cooling Capacity Function of Flow Fraction Curve Name
Measured_C_EIR_FunctionOfTemp_HighSpeed, !- Speed 2 Energy Input Ratio Function of Temperature Curve Name
Constant 1, !- Speed 2 Energy Input Ratio Function of Flow Fraction Curve Name
Measured_HandC_PLC_Simple, !- Speed 2 Part Load Fraction Correlation Curve Name
, !- Speed 2 Nominal Time for Condensate Removal to Begin {s}
, !- Speed 2 Ratio of Initial Moisture Evaporation Rate and steady state Latent Capacity {dimensionless}
, !- Speed 2 Maximum Cycling Rate {cycles/hr}
, !- Speed 2 Latent Capacity Time Constant {s}
, !- Speed 2 Rated Waste Heat Fraction of Power Input {dimensionless}
, !- Speed 2 Waste Heat Function of Temperature Curve Name
, !- Speed 2 Evaporative Condenser Effectiveness {dimensionless}
, !- Speed 2 Evaporative Condenser Air Flow Rate {m3/s}
; !- Speed 2 Rated Evaporative Condenser Pump Power Consumption {W}
!- =========== ALL OBJECTS IN CLASS: COIL:HEATING:DX:MULTISPEED ===========
Coil:Heating:DX:MultiSpeed,
Heating Coil, !- Name
, !- Availability Schedule Name
ClgCoil Outlet, !- Air Inlet Node Name
HtgCoil Outlet, !- Air Outlet Node Name
-8, !- Minimum Outdoor Dry-Bulb Temperature for Compressor Operation {C}
, !- Outdoor Dry-Bulb Temperature to Turn On Compressor {C}
, !- Crankcase Heater Capacity {W}
10, !- Maximum Outdoor Dry-Bulb Temperature for Crankcase Heater Operation {C}
Defrost_EIR_FunctionofTemp_NeverUsed, !- Defrost Energy Input Ratio Function of Temperature Curve Name
5, !- Maximum Outdoor Dry-Bulb Temperature for Defrost Operation {C}
ReverseCycle, !- Defrost Strategy
Timed, !- Defrost Control
0.058333, !- Defrost Time Period Fraction
, !- Resistive Defrost Heater Capacity {W}
No, !- Apply Part Load Fraction to Speeds Greater than 1
Electricity, !- Fuel Type
, !- Region number for Calculating HSPF
2, !- Number of Speeds
9351.763196, !- Speed 1 Gross Rated Heating Capacity {W}
4.167, !- Speed 1 Gross Rated Heating COP {W/W}
0.495, !- Speed 1 Rated Air Flow Rate {m3/s}
, !- Speed 1 Rated Supply Air Fan Power Per Volume Flow Rate {W/(m3/s)}
Measured_H_Cap_FunctionOfTemperature_LowSpeed, !- Speed 1 Heating Capacity Function of Temperature Curve Name
Constant 1, !- Speed 1 Heating Capacity Function of Flow Fraction Curve Name
Measured_H_EIR_FunctionOfTemperature_LowSpeed, !- Speed 1 Energy Input Ratio Function of Temperature Curve Name
Constant 1, !- Speed 1 Energy Input Ratio Function of Flow Fraction Curve Name
Measured_HandC_PLC_Simple, !- Speed 1 Part Load Fraction Correlation Curve Name
0.2, !- Speed 1 Rated Waste Heat Fraction of Power Input {dimensionless}
, !- Speed 1 Waste Heat Function of Temperature Curve Name
13766.29261, !- Speed 2 Gross Rated Heating Capacity {W}
3.953, !- Speed 2 Gross Rated Heating COP {W/W}
0.752, !- Speed 2 Rated Air Flow Rate {m3/s}
, !- Speed 2 Rated Supply Air Fan Power Per Volume Flow Rate {W/(m3/s)}
Measured_H_Cap_FunctionOfTemperature_HighSpeed, !- Speed 2 Heating Capacity Function of Temperature Curve Name
Constant 1, !- Speed 2 Heating Capacity Function of Flow Fraction Curve Name
Measured_H_EIR_FunctionOfTemperature_Highspeed, !- Speed 2 Energy Input Ratio Function of Temperature Curve Name
Constant 1, !- Speed 2 Energy Input Ratio Function of Flow Fraction Curve Name
Measured_HandC_PLC_Simple, !- Speed 2 Part Load Fraction Correlation Curve Name
0.2, !- Speed 2 Rated Waste Heat Fraction of Power Input {dimensionless}
; !- Speed 2 Waste Heat Function of Temperature Curve Name
!- =========== ALL OBJECTS IN CLASS: AIRLOOPHVAC:UNITARYSYSTEM ===========
AirLoopHVAC:UnitarySystem,
Unitary System, !- Name
Load, !- Control Type
ThermalZone1, !- Controlling Zone or Thermostat Location
None, !- Dehumidification Control Type
School in Session Boolean, !- Availability Schedule Name
Mixed Air Node, !- Air Inlet Node Name
HtgCoil Outlet, !- Air Outlet Node Name
Fan:SystemModel, !- Supply Fan Object Type
Fan, !- Supply Fan Name
BlowThrough, !- Fan Placement
Fan Continuous Operation,!- Supply Air Fan Operating Mode Schedule Name
Coil:Heating:DX:MultiSpeed, !- Heating Coil Object Type
Heating Coil, !- Heating Coil Name
1, !- DX Heating Coil Sizing Ratio
Coil:Cooling:DX:MultiSpeed, !- Cooling Coil Object Type
Cooling Coil, !- Cooling Coil Name
No, !- Use DOAS DX Cooling Coil
2, !- Minimum Supply Air Temperature {C}
SensibleOnlyLoadControl, !- Latent Load Control
, !- Supplemental Heating Coil Object Type
, !- Supplemental Heating Coil Name
SupplyAirFlowRate, !- Cooling Supply Air Flow Rate Method
0.752, !- Cooling Supply Air Flow Rate {m3/s}
, !- Cooling Supply Air Flow Rate Per Floor Area {m3/s-m2}
, !- Cooling Fraction of Autosized Cooling Supply Air Flow Rate
, !- Cooling Supply Air Flow Rate Per Unit of Capacity {m3/s-W}
SupplyAirFlowRate, !- Heating Supply Air Flow Rate Method
0.752, !- Heating Supply Air Flow Rate {m3/s}
, !- Heating Supply Air Flow Rate Per Floor Area {m3/s-m2}
, !- Heating Fraction of Autosized Heating Supply Air Flow Rate
, !- Heating Supply Air Flow Rate Per Unit of Capacity {m3/s-W}
SupplyAirFlowRate, !- No Load Supply Air Flow Rate Method
0.433, !- No Load Supply Air Flow Rate {m3/s}
, !- No Load Supply Air Flow Rate Per Floor Area {m3/s-m2}
, !- No Load Fraction of Autosized Cooling Supply Air Flow Rate
, !- No Load Fraction of Autosized Heating Supply Air Flow Rate
, !- No Load Supply Air Flow Rate Per Unit of Capacity During Cooling Operation {m3/s-W}
, !- No Load Supply Air Flow Rate Per Unit of Capacity During Heating Operation {m3/s-W}
40, !- Maximum Supply Air Temperature {C}
21, !- Maximum Outdoor Dry-Bulb Temperature for Supplemental Heater Operation {C}
, !- Outdoor Dry-Bulb Temperature Sensor Node Name
2.5, !- Maximum Cycling Rate {cycles/hr}
, !- Heat Pump Time Constant {s}
, !- Fraction of On-Cycle Power Use
, !- Heat Pump Fan Delay Time {s}
0, !- Ancillary On-Cycle Electric Power {W}
0, !- Ancillary Off-Cycle Electric Power {W}
, !- Design Heat Recovery Water Flow Rate {m3/s}
, !- Maximum Temperature for Heat Recovery {C}
, !- Heat Recovery Water Inlet Node Name
, !- Heat Recovery Water Outlet Node Name
UnitarySystemPerformance:Multispeed, !- Design Specification Multispeed Object Type
Unitary Multispeed Performance; !- Design Specification Multispeed Object Name
!- =========== ALL OBJECTS IN CLASS: UNITARYSYSTEMPERFORMANCE:MULTISPEED ===========
UnitarySystemPerformance:Multispeed,
Unitary Multispeed Performance, !- Name
2, !- Number of Speeds for Heating
2, !- Number of Speeds for Cooling
Yes, !- Single Mode Operation
0.578, !- No Load Supply Air Flow Rate Ratio
0.658, !- Heating Speed 1 Supply Air Flow Ratio
0.658, !- Cooling Speed 1 Supply Air Flow Ratio
1, !- Heating Speed 2 Supply Air Flow Ratio
1; !- Cooling Speed 2 Supply Air Flow Ratio
!- =========== ALL OBJECTS IN CLASS: CONTROLLER:OUTDOORAIR ===========
Controller:OutdoorAir,
Controller Outdoor Air 1,!- Name
Relief Air Outlet Node, !- Relief Air Outlet Node Name
Air Loop Inlet, !- Return Air Node Name
Mixed Air Node, !- Mixed Air Node Name
Outside Air Inlet Node, !- Actuator Node Name
0.498, !- Minimum Outdoor Air Flow Rate {m3/s}
0.498, !- Maximum Outdoor Air Flow Rate {m3/s}
NoEconomizer, !- Economizer Control Type
, !- Economizer Control Action Type
, !- Economizer Maximum Limit Dry-Bulb Temperature {C}
, !- Economizer Maximum Limit Enthalpy {J/kg}
, !- Economizer Maximum Limit Dewpoint Temperature {C}
, !- Electronic Enthalpy Limit Curve Name
, !- Economizer Minimum Limit Dry-Bulb Temperature {C}
NoLockout, !- Lockout Type
FixedMinimum, !- Minimum Limit Type
OA Flow Fraction Schedule, !- Minimum Outdoor Air Schedule Name
, !- Minimum Fraction of Outdoor Air Schedule Name
, !- Maximum Fraction of Outdoor Air Schedule Name
, !- Mechanical Ventilation Controller Name
, !- Time of Day Economizer Control Schedule Name
No, !- High Humidity Control
, !- Humidistat Control Zone Name
, !- High Humidity Outdoor Air Flow Ratio
No, !- Control High Indoor Humidity Based on Outdoor Humidity Ratio
BypassWhenWithinEconomizerLimits; !- Heat Recovery Bypass Control Type
!- =========== ALL OBJECTS IN CLASS: AIRLOOPHVAC ===========
AirLoopHVAC,
Packaged Rooftop Heat Pump, !- Name
, !- Controller List Name
, !- Availability Manager List Name
0.752, !- Design Supply Air Flow Rate {m3/s}
Packaged Rooftop Heat Pump Supply Branches, !- Branch List Name
, !- Connector List Name
Air Loop Inlet, !- Supply Side Inlet Node Name
Node 5, !- Demand Side Outlet Node Name
Packaged Rooftop Heat Pump Demand Inlet Nodes, !- Demand Side Inlet Node Names
Packaged Rooftop Heat Pump Supply Outlet Nodes; !- Supply Side Outlet Node Names
