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Fix #10663 - Fan runtime fraction < 1 when flow rate scaling using DesignSpecification:ZoneHVAC:Sizing #10673
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@@ -1011,7 +1011,7 @@ namespace WindowAC { | |||
zoneEqSizing.SizingMethod(SizingMethod) = CapSizingMethod; | |||
if (CapSizingMethod == CoolingDesignCapacity || CapSizingMethod == CapacityPerFloorArea || | |||
CapSizingMethod == FractionOfAutosizedCoolingCapacity) { | |||
if (CapSizingMethod == HeatingDesignCapacity) { | |||
if (CapSizingMethod == CoolingDesignCapacity) { |
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This was an existing logic error that I noticed
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Good catch. Without example files or unit tests these are hard to find.
// Make the Fan be sized by this | ||
zoneEqSizing.CoolingAirFlow = true; | ||
zoneEqSizing.CoolingAirVolFlow = windowAC.MaxAirVolFlow; |
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This will size the Fan to match.
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EnergyPlus/src/EnergyPlus/Autosizing/SystemAirFlowSizing.cc
Lines 237 to 238 in f274ccb
} else if (this->zoneEqSizing(this->curZoneEqNum).CoolingAirFlow && !this->zoneEqSizing(this->curZoneEqNum).HeatingAirFlow) { | |
this->autoSizedValue = this->dataFracOfAutosizedCoolingAirflow * this->zoneEqSizing(this->curZoneEqNum).CoolingAirVolFlow; |
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In SystemAirFlowSizing, if CoolingAirVolFlow = windowAC.MaxAirVolFlow (which should be already adjusted?) and dataFracOfAutosizedCoolingAirflow = the target fraction, then how does this get the right answer? I would think this would either be 1 * adjusted air flow
or fraction * design air flow
. This looks like it's fraction * adjusted air flow
. Maybe windowAC.MaxAirVolFlow is the design air flow which gets multiplied by the fraction. In any event you are getting the right answer now.
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Apologies, I linked to the wrong bit in SystemAirFlowSizing. The correct bit is:
EnergyPlus/src/EnergyPlus/Autosizing/SystemAirFlowSizing.cc
Lines 619 to 620 in 54f875d
if (this->zoneEqSizing(this->curZoneEqNum).CoolingAirFlow && !this->zoneEqSizing(this->curZoneEqNum).HeatingAirFlow) { | |
this->autoSizedValue = this->zoneEqSizing(this->curZoneEqNum).CoolingAirVolFlow; |
Process 2757796 stopped
* thread #1, name = 'energyplus', stop reason = step over
frame #0: 0x00007ffff50d4370 libenergyplusapi.so.24.2.0`EnergyPlus::SystemAirFlowSizer::size(this=0x00007fffffff4d88, state=0x00007fffffffa980, _originalValue=-99999, errorsFound=0x00007fffffff529f) at SystemAirFlowSizing.cc:620:54
617 }
618 } else {
619 if (this->zoneEqSizing(this->curZoneEqNum).CoolingAirFlow && !this->zoneEqSizing(this->curZoneEqNum).HeatingAirFlow) {
-> 620 this->autoSizedValue = this->zoneEqSizing(this->curZoneEqNum).CoolingAirVolFlow;
621 if (this->finalZoneSizing(this->curZoneEqNum).CoolDDNum > 0 &&
622 this->finalZoneSizing(this->curZoneEqNum).CoolDDNum <= state.dataEnvrn->TotDesDays) {
623 DDNameFanPeak = state.dataWeather->DesDayInput(this->finalZoneSizing(this->curZoneEqNum).CoolDDNum).Title;
(lldb) p this->zoneEqSizing(this->curZoneEqNum).CoolingAirVolFlow
(Real64) 0.28246116346780509
" WindowACSizing; !- Design Specification ZoneHVAC Sizing Object Name", | ||
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// NOTE: Only difference here is that I'm settting a DesignSpecification:ZoneHVAC:Sizing | ||
" DesignSpecification:ZoneHVAC:Sizing,", | ||
" WindowACSizing, !- Name", | ||
" FractionOfAutosizedCoolingAirflow, !- Cooling Supply Air Flow Rate Method", | ||
" , !- Cooling Supply Air Flow Rate {m3/s}", | ||
" , !- Cooling Supply Air Flow Rate Per Floor Area {m3/s-m2}", | ||
" 0.5, !- Cooling Fraction of Autosized Cooling Supply Air Flow Rate", | ||
" , !- Cooling Supply Air Flow Rate Per Unit Cooling Capacity {m3/s-W}", | ||
" FractionOfAutosizedCoolingAirflow, !- No Load Supply Air Flow Rate Method", | ||
" , !- No Load Supply Air Flow Rate {m3/s}", | ||
" , !- No Load Supply Air Flow Rate Per Floor Area {m3/s-m2}", | ||
" 0.5, !- No Load Fraction of Cooling Supply Air Flow Rate", | ||
" , !- No Load Fraction of Heating Supply Air Flow Rate", | ||
" None, !- Heating Supply Air Flow Rate Method", | ||
" , !- Heating Supply Air Flow Rate {m3/s}", | ||
" , !- Heating Supply Air Flow Rate Per Floor Area {m3/s-m2}", | ||
" , !- Heating Fraction of Heating Supply Air Flow Rate", | ||
" , !- Heating Supply Air Flow Rate Per Unit Heating Capacity {m3/s-W}", | ||
" FractionOfAutosizedCoolingCapacity, !- Cooling Design Capacity Method", | ||
" , !- Cooling Design Capacity {W}", | ||
" , !- Cooling Design Capacity Per Floor Area {W/m2}", | ||
" 0.5; !- Fraction of Autosized Cooling Design Capacity", |
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New unit test that uses a DesignSpecification:ZoneHVAC:Sizing
double constexpr expected_full_airflow = 0.041484382187390034; | ||
double constexpr scaler_cooling_saf = 0.5; | ||
double constexpr scaler_cooling_cap = 0.5; | ||
double constexpr expected_full_cap = 622.50474573886743; | ||
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auto const &windowAC = state->dataWindowAC->WindAC(compIndex); | ||
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ASSERT_GT(windowAC.FanIndex, 0); | ||
auto const &fan = state->dataFans->fans(windowAC.FanIndex); | ||
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auto const &finalZoneSizing = state->dataSize->FinalZoneSizing(1); | ||
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EXPECT_NEAR(expected_full_airflow, finalZoneSizing.DesCoolVolFlow, 0.0001); | ||
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ASSERT_GT(windowAC.HVACSizingIndex, 0); | ||
auto const &zoneHVACSizing = state->dataSize->ZoneHVACSizing(windowAC.HVACSizingIndex); | ||
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EXPECT_EQ(DataSizing::FractionOfAutosizedCoolingAirflow, zoneHVACSizing.CoolingSAFMethod); | ||
EXPECT_EQ(scaler_cooling_saf, zoneHVACSizing.MaxCoolAirVolFlow); | ||
EXPECT_EQ(DataSizing::FractionOfAutosizedCoolingCapacity, zoneHVACSizing.CoolingCapMethod); | ||
EXPECT_EQ(scaler_cooling_cap, zoneHVACSizing.ScaledCoolingCapacity); | ||
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EXPECT_EQ(windowAC.DXCoilType_Num, HVAC::Coil_CoolingAirToAirVariableSpeed); | ||
ASSERT_GT(windowAC.DXCoilIndex, 0); | ||
auto const &varSpeedCoil = state->dataVariableSpeedCoils->VarSpeedCoil(windowAC.DXCoilIndex); | ||
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// check Sizing | ||
EXPECT_NEAR(expected_full_airflow * scaler_cooling_saf, windowAC.MaxAirVolFlow, 0.0001); | ||
EXPECT_NEAR(expected_full_airflow * scaler_cooling_saf, fan->maxAirFlowRate, 0.0001); |
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Check that the Fan too is size at 0.5 of full flow
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From my previous comment about SystemAirFlowSizing, windowAC.MaxAirVolFlow is already adjusted. Now I'm confused.
EXPECT_NEAR(expected_full_airflow * scaler_cooling_saf, windowAC.MaxAirVolFlow, 0.0001); | ||
EXPECT_NEAR(expected_full_airflow * scaler_cooling_saf, fan->maxAirFlowRate, 0.0001); | ||
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EXPECT_NEAR(622.505, varSpeedCoil.RatedCapCoolTotal, 0.001); |
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Note that the Coil:Cooling:DX:VariableSpeed is not affected.
- I don't know if we would want that.
- SizeVarSpeedCoil seem to not call the Autosizing modules. Instead, it uses the FinalZoneSizing's DesCoolVolFlow / DesCoolHeatFlow. cf
EnergyPlus/src/EnergyPlus/VariableSpeedCoils.cc
Lines 4715 to 4717 in f274ccb
CheckZoneSizing(state, format("COIL:{}{}", varSpeedCoil.CoolHeatType, CurrentObjSubfix), varSpeedCoil.Name); RatedAirVolFlowRateDes = max(state.dataSize->FinalZoneSizing(state.dataSize->CurZoneEqNum).DesCoolVolFlow, state.dataSize->FinalZoneSizing(state.dataSize->CurZoneEqNum).DesHeatVolFlow);
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The VS coil should be adjusted but it was never converted to use the sizing routines. That begs an open issue to adjust VS coil sizing when DesignSpecification:ZoneHVAC:Sizing is used.
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Filed at #10699
// capacity sizing methods (HeatingDesignCapacity, CapacityPerFloorArea, FractionOfAutosizedCoolingCapacity, and | ||
// FractionOfAutosizedHeatingCapacity ) | ||
int const CapSizingMethod = zoneHVACSizing.CoolingCapMethod; | ||
zoneEqSizing.SizingMethod(SizingMethod) = CapSizingMethod; |
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Note: I'm not sure if this is right... (this is pre-existing)
At this point in time, SizingMethod is either HVAC::CoolingAirflowSizing
, or HVAC::CoolingCapacitySizing
if the SAFMethod is FlowPerCoolingCapacity
.
I think the intent here is to set the CoolingCapacitySizing method specifically, so it should be HVAC::CoolingCapacitySizing
, right?
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The intent for FlowPerCoolingCapacity is:
- calc design capacity using zone design air flow rate
- set fraction that will adjust zone design air flow when air flow is sized (which will also adjust capacity when capacity is sized)
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just to be clear, you're saying this is currently correct right?
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Then the next time you call using HVAC::CoolingCapacitySizing the adjusted air flow rate would be used. It appears to me that the capacity sizer should be called here using SizingMethod = HVAC::CoolingCapacitySizing;. It looks like 1) state.dataSize->DataFlowUsedForSizing was not reset above to be an air flow rate (and DataFlowPerCoolingCapacity should be reset to 0), and 2) the sizing method should be explicitly set for capacity sizing (right now is looks to still be fraction of capacity).
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If you single step this a couple times you should see the capacity getting set using zone design air flow, the air flow being adjusted based on capacity, and the capacity being calculated again using the new air flow rate.
… the variables, initialize them, don't check 4 times if CurZoneEqNum is > 0
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Note: these files are on DefectFiles support repo. Taking the WindACAuto.idf and a modified Version WindACAutoScaled.idf that adds a I also added
There is zero change for the WindACAuto.idf, as expected. |
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This does look right except that 1 question with SystemAirFlowSizing.
// capacity sizing methods (HeatingDesignCapacity, CapacityPerFloorArea, FractionOfAutosizedCoolingCapacity, and | ||
// FractionOfAutosizedHeatingCapacity ) | ||
int const CapSizingMethod = zoneHVACSizing.CoolingCapMethod; | ||
zoneEqSizing.SizingMethod(SizingMethod) = CapSizingMethod; |
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The intent for FlowPerCoolingCapacity is:
- calc design capacity using zone design air flow rate
- set fraction that will adjust zone design air flow when air flow is sized (which will also adjust capacity when capacity is sized)
@@ -1011,7 +1011,7 @@ namespace WindowAC { | |||
zoneEqSizing.SizingMethod(SizingMethod) = CapSizingMethod; | |||
if (CapSizingMethod == CoolingDesignCapacity || CapSizingMethod == CapacityPerFloorArea || | |||
CapSizingMethod == FractionOfAutosizedCoolingCapacity) { | |||
if (CapSizingMethod == HeatingDesignCapacity) { | |||
if (CapSizingMethod == CoolingDesignCapacity) { |
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Good catch. Without example files or unit tests these are hard to find.
// Make the Fan be sized by this | ||
zoneEqSizing.CoolingAirFlow = true; | ||
zoneEqSizing.CoolingAirVolFlow = windowAC.MaxAirVolFlow; |
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In SystemAirFlowSizing, if CoolingAirVolFlow = windowAC.MaxAirVolFlow (which should be already adjusted?) and dataFracOfAutosizedCoolingAirflow = the target fraction, then how does this get the right answer? I would think this would either be 1 * adjusted air flow
or fraction * design air flow
. This looks like it's fraction * adjusted air flow
. Maybe windowAC.MaxAirVolFlow is the design air flow which gets multiplied by the fraction. In any event you are getting the right answer now.
double constexpr expected_full_airflow = 0.041484382187390034; | ||
double constexpr scaler_cooling_saf = 0.5; | ||
double constexpr scaler_cooling_cap = 0.5; | ||
double constexpr expected_full_cap = 622.50474573886743; | ||
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auto const &windowAC = state->dataWindowAC->WindAC(compIndex); | ||
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ASSERT_GT(windowAC.FanIndex, 0); | ||
auto const &fan = state->dataFans->fans(windowAC.FanIndex); | ||
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auto const &finalZoneSizing = state->dataSize->FinalZoneSizing(1); | ||
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EXPECT_NEAR(expected_full_airflow, finalZoneSizing.DesCoolVolFlow, 0.0001); | ||
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ASSERT_GT(windowAC.HVACSizingIndex, 0); | ||
auto const &zoneHVACSizing = state->dataSize->ZoneHVACSizing(windowAC.HVACSizingIndex); | ||
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EXPECT_EQ(DataSizing::FractionOfAutosizedCoolingAirflow, zoneHVACSizing.CoolingSAFMethod); | ||
EXPECT_EQ(scaler_cooling_saf, zoneHVACSizing.MaxCoolAirVolFlow); | ||
EXPECT_EQ(DataSizing::FractionOfAutosizedCoolingCapacity, zoneHVACSizing.CoolingCapMethod); | ||
EXPECT_EQ(scaler_cooling_cap, zoneHVACSizing.ScaledCoolingCapacity); | ||
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EXPECT_EQ(windowAC.DXCoilType_Num, HVAC::Coil_CoolingAirToAirVariableSpeed); | ||
ASSERT_GT(windowAC.DXCoilIndex, 0); | ||
auto const &varSpeedCoil = state->dataVariableSpeedCoils->VarSpeedCoil(windowAC.DXCoilIndex); | ||
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// check Sizing | ||
EXPECT_NEAR(expected_full_airflow * scaler_cooling_saf, windowAC.MaxAirVolFlow, 0.0001); | ||
EXPECT_NEAR(expected_full_airflow * scaler_cooling_saf, fan->maxAirFlowRate, 0.0001); |
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From my previous comment about SystemAirFlowSizing, windowAC.MaxAirVolFlow is already adjusted. Now I'm confused.
EXPECT_NEAR(expected_full_airflow * scaler_cooling_saf, windowAC.MaxAirVolFlow, 0.0001); | ||
EXPECT_NEAR(expected_full_airflow * scaler_cooling_saf, fan->maxAirFlowRate, 0.0001); | ||
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EXPECT_NEAR(622.505, varSpeedCoil.RatedCapCoolTotal, 0.001); |
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The VS coil should be adjusted but it was never converted to use the sizing routines. That begs an open issue to adjust VS coil sizing when DesignSpecification:ZoneHVAC:Sizing is used.
Thanks for the review on this @rraustad, seems like this is very close, just maybe one remaining issue. |
This data shows that the single speed DX coil air flow was adjusted so it follows that the VS DX coil air flow should also be adjusted. Also in this data, why is the window AC scaled-ori and scaled-new values both equal to 0.02832 and the single speed DX coil air flow rate different? |
} | ||
bool errorsFound = false; | ||
CoolingCapacitySizer sizerCoolingCapacity; | ||
sizerCoolingCapacity.overrideSizingString(SizingString); | ||
sizerCoolingCapacity.overrideSizingString(""); | ||
sizerCoolingCapacity.initializeWithinEP(state, CompType, CompName, PrintFlag, RoutineName); | ||
state.dataSize->DataCapacityUsedForSizing = sizerCoolingCapacity.size(state, TempSize, errorsFound); |
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Yes, this does look correct. Call the cooling capacity sizer which uses zone design air flow.
sizerCoolingCapacity.initializeWithinEP(state, CompType, CompName, PrintFlag, RoutineName); | ||
state.dataSize->DataCapacityUsedForSizing = sizerCoolingCapacity.size(state, TempSize, errorsFound); | ||
state.dataSize->DataFlowPerCoolingCapacity = state.dataSize->ZoneHVACSizing(zoneHVACIndex).MaxCoolAirVolFlow; | ||
state.dataSize->DataFlowPerCoolingCapacity = zoneHVACSizing.MaxCoolAirVolFlow; |
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Set the fraction of air flow here
sizingCoolingAirFlow.initializeWithinEP(state, CompType, CompName, PrintFlag, RoutineName); | ||
state.dataWindowAC->WindAC(WindACNum).MaxAirVolFlow = sizingCoolingAirFlow.size(state, TempSize, errorsFound); | ||
windowAC.MaxAirVolFlow = sizingCoolingAirFlow.size(state, TempSize, errorsFound); |
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And then size that new air flow rate here. You should also reset state.dataSize->DataFlowPerCoolingCapacity here to be a flow rate instead of a fraction.
@jmarrec these global fraction variables are hard to get right. It may be correct now, just check to make sure the final scaled values are as expected. |
For some reason, probably lack of understanding, I'm severely confused about what's being asked here. Code linting and unit test aside, I haven't touched the sections that are being commented. The actual changes are https://github.com/NREL/EnergyPlus/pull/10673/files/5dbc7b13c8597788540474a075a5eab678a3ce12..a5d32dea2e5a7ea6c68c38b6f073176a9cdc9ce1 I've been looking at other files to see if I could figure out what may be different here compared to other objects EnergyPlus/src/EnergyPlus/WindowAC.cc Lines 977 to 1003 in a5d32de
eg taking FanCoilUnits, EnergyPlus/src/EnergyPlus/FanCoilUnits.cc Lines 1294 to 1314 in a5d32de
Rewritting a bit the code to miminize diffs: --- WindowAC.blob.cc 2024-09-12 12:17:47.094657049 +0200
+++ FanCoilUnits.blob.cc 2024-09-12 12:18:03.988792981 +0200
@@ -2,22 +2,21 @@
SizingMethod = HVAC::CoolingCapacitySizing;
TempSize = DataSizing::AutoSize;
PrintFlag = false;
- state.dataSize->DataScalableSizingON = true;
- state.dataSize->DataFlowUsedForSizing = state.dataSize->FinalZoneSizing(state.dataSize->CurZoneEqNum).DesCoolVolFlow;
- if (zoneHVACSizing.CoolingCapMethod == FractionOfAutosizedCoolingCapacity) {
- state.dataSize->DataFracOfAutosizedCoolingCapacity = zoneHVACSizing.ScaledCoolingCapacity;
- }
bool errorsFound = false;
CoolingCapacitySizer sizerCoolingCapacity;
sizerCoolingCapacity.overrideSizingString("");
sizerCoolingCapacity.initializeWithinEP(state, CompType, CompName, PrintFlag, RoutineName);
- state.dataSize->DataCapacityUsedForSizing = sizerCoolingCapacity.size(state, TempSize, errorsFound);
+ state.dataSize->DataAutosizedCoolingCapacity = sizerCoolingCapacity.size(state, TempSize, errorsFound);
+ if (zoneHVACSizing.CoolingCapMethod == DataSizing::FractionOfAutosizedCoolingCapacity) {
+ state.dataSize->DataFracOfAutosizedCoolingCapacity = zoneHVACSizing.ScaledCoolingCapacity;
+ }
state.dataSize->DataFlowPerCoolingCapacity = zoneHVACSizing.MaxCoolAirVolFlow;
PrintFlag = true;
TempSize = DataSizing::AutoSize;
errorsFound = false;
+ state.dataSize->DataScalableSizingON = true;
CoolingAirFlowSizer sizingCoolingAirFlow;
sizingCoolingAirFlow.overrideSizingString(SizingString);
sizingCoolingAirFlow.initializeWithinEP(state, CompType, CompName, PrintFlag, RoutineName);
- windowAC.MaxAirVolFlow = sizingCoolingAirFlow.size(state, TempSize, errorsFound);
+ CoolingAirVolFlowDes = sizingCoolingAirFlow.size(state, TempSize, errorsFound);
} |
@jmarrec @Myoldmopar it has been 28 days since this pull request was last updated. |
1 similar comment
@jmarrec @Myoldmopar it has been 28 days since this pull request was last updated. |
@jmarrec it has been 15 days since this pull request was last updated. |
Pull request overview
DesignSpecification:ZoneHVAC:Sizing
#10663Pull Request Author
Add to this list or remove from it as applicable. This is a simple templated set of guidelines.
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This will not be exhaustively relevant to every PR.