Hi, Kelvin,
Have you got an anwer for your question?
If your question is on why using a setpoint for the supply air and not directly controlled by the thermostat, the reason is that if one zone thermostat is use to control the supply air temperature, only the control zone would have the desired temperature. The thermostats in the slave zones have no control. If the load pattern of the slave zones is not same as the controlled zone, the slave zone will have different temperature values.
By using the setpoint manager to control the supply air, all the zone thermostats are available for the use of each zone. In general, the supply air is set to over cooling condition, and a reheat heater is used to adjust the zone temperature. The use of a VAV dampler can also control the zone temperature within the designed load demand conditions. This is however not an energy saving configuration.
The direct thermostat control can be sue for all the Dx, gas, electric, or water coils.
Because of the introduction of the HVACtemplate:system:VAV, very few new users know that the master/slave thermostat control can also be applied to a multizone air loop.
In the example files, the direct thermostat control of the coil is usually for the zone equippment only. For multi-zone air loop, the VAV example is used, therefore no direct control by the zone thermostat for the supply air.
You said in an older mail below:, "the zone temperature in winter time can't be maintained."
PSZ_1:1 Supply Equipment Outlet Node, !- Sensor Node Name
Should this be the zone node, where the thermostat is mounted. Somehow, it has to be linked to the heating set point schedule and not a fixed number.. The coil air outlet node temperature is usually higher than the zone temperature. That is again a VAV air loop design condition, which requires. damper control.
The control variable "Flow" seems to limit the control to flow volume and not on/off as in the Dx coil.
I wonder, what happens, if you connect a zone fan coil unit and use it to feed multi-zone.
I have not found the definite answer yet.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: xukevin24@xxxxxxxxx
Date: Fri, 27 Jul 2012 22:33:25 +0000
Subject: [EnergyPlus_Support] Re: How to set up a Coil:Heating:Water object in a CAV system to controls?
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Primary EnergyPlus support is found at:
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The primary EnergyPlus web site is found at:
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Have you got an anwer for your question?
If your question is on why using a setpoint for the supply air and not directly controlled by the thermostat, the reason is that if one zone thermostat is use to control the supply air temperature, only the control zone would have the desired temperature. The thermostats in the slave zones have no control. If the load pattern of the slave zones is not same as the controlled zone, the slave zone will have different temperature values.
By using the setpoint manager to control the supply air, all the zone thermostats are available for the use of each zone. In general, the supply air is set to over cooling condition, and a reheat heater is used to adjust the zone temperature. The use of a VAV dampler can also control the zone temperature within the designed load demand conditions. This is however not an energy saving configuration.
The direct thermostat control can be sue for all the Dx, gas, electric, or water coils.
Because of the introduction of the HVACtemplate:system:VAV, very few new users know that the master/slave thermostat control can also be applied to a multizone air loop.
In the example files, the direct thermostat control of the coil is usually for the zone equippment only. For multi-zone air loop, the VAV example is used, therefore no direct control by the zone thermostat for the supply air.
You said in an older mail below:, "the zone temperature in winter time can't be maintained."
PSZ_1:1 Supply Equipment Outlet Node, !- Sensor Node Name
Should this be the zone node, where the thermostat is mounted. Somehow, it has to be linked to the heating set point schedule and not a fixed number.. The coil air outlet node temperature is usually higher than the zone temperature. That is again a VAV air loop design condition, which requires. damper control.
The control variable "Flow" seems to limit the control to flow volume and not on/off as in the Dx coil.
I wonder, what happens, if you connect a zone fan coil unit and use it to feed multi-zone.
I have not found the definite answer yet.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: xukevin24@xxxxxxxxx
Date: Fri, 27 Jul 2012 22:33:25 +0000
Subject: [EnergyPlus_Support] Re: How to set up a Coil:Heating:Water object in a CAV system to controls?
I feel the same way. Most of hot water coils are controlled to maintain the supply air temperature set point, but in some cases, especially for single zone CAV unit, the hot water valve could be controlled directly to maintain zone temperature set point. Just curious why gas furnace can be set up that way, but not for the water coils.
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Griffith, Brent" <brent.griffith@...> wrote:
>
> The water coil controller works better when it uses the coil air outlet node for the sensor node.
>
> From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Ke Xu
> Sent: Friday, July 27, 2012 1:57 PM
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> 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<mailto:EnergyPlus_Support%40yahoogroups.com>, "Ke Xu" <xukevin24@<mailto: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
> >
>
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Griffith, Brent" <brent.griffith@...> wrote:
>
> The water coil controller works better when it uses the coil air outlet node for the sensor node.
>
> From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Ke Xu
> Sent: Friday, July 27, 2012 1:57 PM
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> 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<mailto:EnergyPlus_Support%40yahoogroups.com>, "Ke Xu" <xukevin24@<mailto: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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