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Unsure about autosizing results

asked 2014-12-28 12:14:30 -0500

14031194G gravatar image

updated 2020-03-10 09:54:08 -0500

If I use only one coil in the system and I would like it to be autosize. Am I doing it right there I am not very sure. image description image description

Coil:Cooling:DX:TwoStageWithHumidityControlMode,
DOAS Cooling Coil, !- Name
HVACTemplate-Always 1, !- Availability Schedule Name
DOAS Supply Fan Outlet, !- Air Inlet Node Name
DOAS Cooling Coil Outlet,!- Air Outlet Node Name
, !- Crankcase Heater Capacity {W}
, !- Maximum Outdoor Dry-Bulb Temperature for Crankcase Heater Operation {C}
1, !- Number of Capacity Stages
0, !- Number of Enhanced Dehumidification Modes
CoilPerformance:DX:Cooling, !- Normal Mode Stage 1 Coil Performance Object Type
DOAS Standard Perf 1, !- Normal Mode Stage 1 Coil Performance Name
CoilPerformance:DX:Cooling, !- Normal Mode Stage 1+2 Coil Performance Object Type
DOAS Standard Perf 1+2; !- Normal Mode Stage 1+2 Coil Performance Name


Sizing:System,
DOAS, !- AirLoop Name
Sensible, !- Type of Load to Size On
autosize, !- Design Outdoor Air Flow Rate {m3/s}
1.0, !- Minimum System Air Flow Ratio
2, !- Preheat Design Temperature {C}
0.008, !- Preheat Design Humidity Ratio {kgWater/kgDryAir}
11, !- Precool Design Temperature {C}
0.008, !- Precool Design Humidity Ratio {kgWater/kgDryAir}
16, !- Central Cooling Design Supply Air Temperature {C}
12.2, !- Central Heating Design Supply Air Temperature {C}
NonCoincident, !- Sizing Option
Yes, !- 100% Outdoor Air in Cooling
Yes, !- 100% Outdoor Air in Heating
0.008, !- Central Cooling Design Supply Air Humidity Ratio {kgWater/kgDryAir}
0.003, !- Central Heating Design Supply Air Humidity Ratio {kgWater/kgDryAir}
DesignDay, !- Cooling Design Air Flow Method
0, !- Cooling Design Air Flow Rate {m3/s}
DesignDay, !- Heating Design Air Flow Method
0, !- Heating Design Air Flow Rate {m3/s}
ZoneSum; !- System Outdoor Air Method

But Design Load is 76kW already but my coil only has 46kW

One more question is that in the Sizing:System I dont have any precool or preheat in the outdoor airduct what should I input there

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Comments

@31415926G. From your input file, I can tell you are using EnergyPlus. In the future, please tag questions with the engine you are using since most questions end up being engine specific.

__AmirRoth__ gravatar image __AmirRoth__  ( 2014-12-29 14:22:51 -0500 )edit

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answered 2015-01-08 12:04:36 -0500

The diagram shows three cooling coils which are all in the outdoor air duct. These will all be sized to deliver the Precool Design Temperature which is 11C in the input above. EnergyPlus sizing does not currently know how to divide the load between multiple coils in series.

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Asked: 2014-12-28 12:14:30 -0500

Seen: 285 times

Last updated: Jan 08 '15