When you use the gas burner, the capacity is probably not limited, or sized to the same value..
Did you use setpointmanager:singlezone:heating with the gas coil? How do you apply this to a multizone AHU? Can the manager be set to monitor the zone temperature, then how does it control the AHU? Draw a little control schematic diagram and see whether the program control make sense.
When you use the water coil and a controller, the capacity is limited by your sizing condition which fixed the supply air volumn to a zone.. If you use a VAV damper, the supply available to the zone is control by the VAV damper sized with a certain condition of air flow volume, and controlled by the zone thermostat. Normally the zone is sized slitly below the zone requirement and then make up by the reheat. You cannot reduce temperature using reheat.
If you are not using VAV damper in the zone, the master zone thermostat should control the AHU. If you use setpoint manaager, the control value should be the average temperature of all zones. I am not sure whether thhis is available.
If you need a reheat coil to make up the capacity, it is an indication that the water coil is under sized or the setpoint temperature is too low. As the zone load may not change in sync, some zone will have different temperature.
Do you have the controller and the setpoint manager for both cases?
The use of setpoint manager fixed the supply air tempeature to a value different from the sizing value., if this value is lower than the required value, the reheat is used to make up the difference. In the master zone control mode, the zone thermostat in the other zones are not operative to control the AHU, but may be avilable for the reheat coil.. Without the reheat, the setpoint not met warning may be issured.
The problem may not be the heating coil difference, but the controller differences or design differences..
SVG diagram only shows the connections. It will not show the sizing or "zone temperature not met" errors.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: xukevin24@xxxxxxxxx
Date: Fri, 27 Jul 2012 20:58:49 +0000
Subject: [EnergyPlus_Support] Re: How to set up a Coil:Heating:Water object in a CAV system to controls?
__._,_.___
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
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Did you use setpointmanager:singlezone:heating with the gas coil? How do you apply this to a multizone AHU? Can the manager be set to monitor the zone temperature, then how does it control the AHU? Draw a little control schematic diagram and see whether the program control make sense.
When you use the water coil and a controller, the capacity is limited by your sizing condition which fixed the supply air volumn to a zone.. If you use a VAV damper, the supply available to the zone is control by the VAV damper sized with a certain condition of air flow volume, and controlled by the zone thermostat. Normally the zone is sized slitly below the zone requirement and then make up by the reheat. You cannot reduce temperature using reheat.
If you are not using VAV damper in the zone, the master zone thermostat should control the AHU. If you use setpoint manaager, the control value should be the average temperature of all zones. I am not sure whether thhis is available.
If you need a reheat coil to make up the capacity, it is an indication that the water coil is under sized or the setpoint temperature is too low. As the zone load may not change in sync, some zone will have different temperature.
Do you have the controller and the setpoint manager for both cases?
The use of setpoint manager fixed the supply air tempeature to a value different from the sizing value., if this value is lower than the required value, the reheat is used to make up the difference. In the master zone control mode, the zone thermostat in the other zones are not operative to control the AHU, but may be avilable for the reheat coil.. Without the reheat, the setpoint not met warning may be issured.
The problem may not be the heating coil difference, but the controller differences or design differences..
SVG diagram only shows the connections. It will not show the sizing or "zone temperature not met" errors.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: xukevin24@xxxxxxxxx
Date: Fri, 27 Jul 2012 20:58:49 +0000
Subject: [EnergyPlus_Support] Re: How to set up a Coil:Heating:Water object in a CAV system to controls?
Dr. Li,
The simulation can run without errors associated with heating system, but the zone temperature in winter can't be maintained. I believe the HW plant loop is properly set up and well connected with the coils, I can tell from SVG document, otherwise, I would receive fatal errors.
I have to modify DOE-reference building to accommodate some specific system requirement-instead of gas burner, boiler has to be used for heating. and I run into this issue. I can solve it by using CAV-reheat as terminal, instead of having heating coil in airloop and use uncontrolled air terminal. I did not expect to have this issue since I see gas burner in the airloop works fine in the reference model, but when i replace it with hot water coils, i have this problem....
--Ke
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> wrote:
>
>
> Cannot tell without the IDF. The error file after running the IDF may tell what is wrong with the code, and it wtill will not tell whether it is designed to work as espected. Why do you need a setpoint manager to control a air loop? If the gas burner works, it means that your plant loop is not properly defined. The coil must be correctly connected in the demmand loop of the HW plant loop with a boiler..
>
> Dr. Li
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> From: xukevin24@...
> Date: Fri, 27 Jul 2012 19:57:04 +0000
> Subject: [EnergyPlus_Support] Re: How to set up a Coil:Heating:Water object in a CAV system to controls?
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Still couldn't make it work. But Gas furnace will work, see those DOE-reference buildings. My understanding is that the setpointmanager:singlezone:heating is not designed to work with water heating coils in the air loop? anyone test it before?
>
> Thanks.
>
>
>
> -Ke
>
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Ke Xu" <xukevin24@> wrote:
>
> >
>
> > Dear all,
>
> > I am simulating a constant air volume system with a hot-water heating coil in the air-loop, and I am trying to set up controls for coil to maintain supply air temperature set point calculated to maintain the zone temperature. the objects I am using include "Coil: Heating: Water", "Controller: WaterCoil" and "SetpointManager:SingZone:Heating". Somehow, it doesn't work as I expected, the zone temperature in winter time can't be maintained. Any help and comments are appreciated. Thanks in advance.
>
> >
>
> > --Ke
>
> >
>
> > Part of my model related with heating coil is shown below:
>
> >
>
> > Coil:Heating:Water,
>
> > PSZ_1:1_HEATC, !- Name
>
> > Always_On, !- Availability Schedule Name
>
> > Autosize, !- U-Factor Times Area Value {W/K}
>
> > Autosize, !- Maximum Water Flow Rate {m3/s}
>
> > PSZ_1:1 HeatingCoilWaterInlet, !- Water Inlet Node Name
>
> > PSZ_1:1 HeatingCoilWaterOutlet, !- Water Outlet Node Name
>
> > PSZ_1:1_CoolC-PSZ_1:1_HeatCNode, !- Air Inlet Node Name
>
> > PSZ_1:1_HeatC-PSZ_1:1_FanNode, !- Air Outlet Node Name
>
> > UFactorTimesAreaAndDesignWaterFlowRate, !- Performance Input Method
>
> > Autosize, !- Rated Capacity {W}
>
> > 82.2222222222222, !- Rated Inlet Water Temperature {C}
>
> > 12.7777781162733, !- Rated Inlet Air Temperature {C}
>
> > 71.1111111111111, !- Rated Outlet Water Temperature {C}
>
> > 43.3333333333334, !- Rated Outlet Air Temperature {C}
>
> > 0.5; !- Rated Ratio for Air and Water Convection
>
> >
>
> > Controller:WaterCoil,
>
> > OS:Controller:WaterCoil 1, !- Name
>
> > Temperature, !- Control Variable
>
> > Normal, !- Action
>
> > Flow, !- Actuator Variable
>
> > PSZ_1:1 Supply Equipment Outlet Node, !- Sensor Node Name
>
> > PSZ_1:1 HeatingCoilWaterInlet, !- Actuator Node Name
>
> > Autosize, !- Controller Convergence Tolerance {deltaC}
>
> > Autosize, !- Maximum Actuated Flow {m3/s}
>
> > 1e-007; !- Minimum Actuated Flow {m3/s}
>
> >
>
> > SetpointManager:SingleZone:Heating,
>
> > SupAirTemp MngrCore_bottom, !- Name
>
> > Temperature, !- Control Variable
>
> > 10.0, !- Minimum Supply Air Temperature {C}
>
> > 43.3333344812747, !- Maximum Supply Air Temperature {C}
>
> > Core_bottom, !- Control Zone Name
>
> > Core_bottom Air Node, !- Zone Node Name
>
> > Core_bottom Direct Air Inlet Node Name, !- Zone Inlet Node Name
>
> > PSZ_1:1 Supply Equipment Outlet Node; !- Setpoint Node or NodeList Name
>
> >
>
The simulation can run without errors associated with heating system, but the zone temperature in winter can't be maintained. I believe the HW plant loop is properly set up and well connected with the coils, I can tell from SVG document, otherwise, I would receive fatal errors.
I have to modify DOE-reference building to accommodate some specific system requirement-instead of gas burner, boiler has to be used for heating. and I run into this issue. I can solve it by using CAV-reheat as terminal, instead of having heating coil in airloop and use uncontrolled air terminal. I did not expect to have this issue since I see gas burner in the airloop works fine in the reference model, but when i replace it with hot water coils, i have this problem....
--Ke
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> wrote:
>
>
> Cannot tell without the IDF. The error file after running the IDF may tell what is wrong with the code, and it wtill will not tell whether it is designed to work as espected. Why do you need a setpoint manager to control a air loop? If the gas burner works, it means that your plant loop is not properly defined. The coil must be correctly connected in the demmand loop of the HW plant loop with a boiler..
>
> Dr. Li
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> From: xukevin24@...
> Date: Fri, 27 Jul 2012 19:57:04 +0000
> Subject: [EnergyPlus_Support] Re: How to set up a Coil:Heating:Water object in a CAV system to controls?
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Still couldn't make it work. But Gas furnace will work, see those DOE-reference buildings. My understanding is that the setpointmanager:singlezone:heating is not designed to work with water heating coils in the air loop? anyone test it before?
>
> Thanks.
>
>
>
> -Ke
>
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Ke Xu" <xukevin24@> wrote:
>
> >
>
> > Dear all,
>
> > I am simulating a constant air volume system with a hot-water heating coil in the air-loop, and I am trying to set up controls for coil to maintain supply air temperature set point calculated to maintain the zone temperature. the objects I am using include "Coil: Heating: Water", "Controller: WaterCoil" and "SetpointManager:SingZone:Heating". Somehow, it doesn't work as I expected, the zone temperature in winter time can't be maintained. Any help and comments are appreciated. Thanks in advance.
>
> >
>
> > --Ke
>
> >
>
> > Part of my model related with heating coil is shown below:
>
> >
>
> > Coil:Heating:Water,
>
> > PSZ_1:1_HEATC, !- Name
>
> > Always_On, !- Availability Schedule Name
>
> > Autosize, !- U-Factor Times Area Value {W/K}
>
> > Autosize, !- Maximum Water Flow Rate {m3/s}
>
> > PSZ_1:1 HeatingCoilWaterInlet, !- Water Inlet Node Name
>
> > PSZ_1:1 HeatingCoilWaterOutlet, !- Water Outlet Node Name
>
> > PSZ_1:1_CoolC-PSZ_1:1_HeatCNode, !- Air Inlet Node Name
>
> > PSZ_1:1_HeatC-PSZ_1:1_FanNode, !- Air Outlet Node Name
>
> > UFactorTimesAreaAndDesignWaterFlowRate, !- Performance Input Method
>
> > Autosize, !- Rated Capacity {W}
>
> > 82.2222222222222, !- Rated Inlet Water Temperature {C}
>
> > 12.7777781162733, !- Rated Inlet Air Temperature {C}
>
> > 71.1111111111111, !- Rated Outlet Water Temperature {C}
>
> > 43.3333333333334, !- Rated Outlet Air Temperature {C}
>
> > 0.5; !- Rated Ratio for Air and Water Convection
>
> >
>
> > Controller:WaterCoil,
>
> > OS:Controller:WaterCoil 1, !- Name
>
> > Temperature, !- Control Variable
>
> > Normal, !- Action
>
> > Flow, !- Actuator Variable
>
> > PSZ_1:1 Supply Equipment Outlet Node, !- Sensor Node Name
>
> > PSZ_1:1 HeatingCoilWaterInlet, !- Actuator Node Name
>
> > Autosize, !- Controller Convergence Tolerance {deltaC}
>
> > Autosize, !- Maximum Actuated Flow {m3/s}
>
> > 1e-007; !- Minimum Actuated Flow {m3/s}
>
> >
>
> > SetpointManager:SingleZone:Heating,
>
> > SupAirTemp MngrCore_bottom, !- Name
>
> > Temperature, !- Control Variable
>
> > 10.0, !- Minimum Supply Air Temperature {C}
>
> > 43.3333344812747, !- Maximum Supply Air Temperature {C}
>
> > Core_bottom, !- Control Zone Name
>
> > Core_bottom Air Node, !- Zone Node Name
>
> > Core_bottom Direct Air Inlet Node Name, !- Zone Inlet Node Name
>
> > PSZ_1:1 Supply Equipment Outlet Node; !- Setpoint Node or NodeList Name
>
> >
>
__._,_.___
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
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