The main problem with your original concept was the use of the zone 01 thermostat for both the primary air loop and the zone fan coil unit.
That was the reason why I ask you to remove the fan coil unit in zone 01, the master zone. This free up the thermostat to operate on the fresh air loop.
The other problem is the zone return air connection.
The air loop is connected to the zone via the ADT:uncontrolled. There are two zone outlets. Exhaust and return air node. In the slave zones use the return for the air loop return, and exhaust for the fan coil return, or vice versa. The fresh air is mixed in the zone, and does not matter how you return it. The loop return air volume is controlled by the total fan capacity and the ADT setting.
However, the local loop and the common loop must have separate return air node. The names of nodes in the return air mixer are not correct, and need to be changed. There should be two of them, one from each zone, and not from the zone OA mixer relief node.
If you wanted to shut off the local fresh air intake, simply reduce the zone OA inlet flow rate to a very smaller value. This can represent the building leak. If you made this quantity large and proportional to the floor area, then you will not need the fresh air intake.
Run the whole building as Zone 03 and 04 with large OA intake, and remove the fresh air loop.
==================
The CBVAV solution is to create a node for the air loop to provide constant temperature air to the zones. That returns the zone thermostat to the master zone. The added by-pass path is acting like a vertual zone for the air loop to adjust its temperature..
With this arrangement, it is not really necessary to have individual thermostat for the zones. Because of duct warming, the temperature away from the AHU will be hotter in Summer. By placing the AHU at the Westerly end of the building would compensate this effect. In my design, I generally have two AHU's to feed the East and Westerly zones, with separate thermostat control.
This is design details, and has nothing to do with simulation.
====================
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: vieira.jose99@xxxxxxxxx
Date: Fri, 15 Apr 2011 14:58:43 +0000
Subject: [EnergyPlus_Support] Re: Zone FanCoils and an AHU
, !- Outdoor Air Flow Rate per Person {m3/s}
0.001388889, !- Outdoor Air Flow Rate per Zone Floor Area {m3/s-m2}
0.0, !- Outdoor Air Flow Rate per Zone {m3/s}
Zone 01 FC, !- Name
On, !- Availability Schedule Name
ConstantFanVariableFlow, !- Capacity Control Method
autosize, !- Maximum Supply Air Flow Rate {m3/s}
0.33, !- Low Speed Supply Air Flow Ratio
0.66, !- Medium Speed Supply Air Flow Ratio
autosize, !- Maximum Outdoor Air Flow Rate {m3/s}
10101, !- Outside Air Schedule Name
FC 01 return node, !- Air Inlet Node Name
zone 01 inlet node, !- Air Outlet Node Name
FC 01 inlet node, !- Outdoor Air Node Name
FC 01 relief outlet node,!- Air Relief Node Name
01 FC OA Mixer, !- Outdoor Air Mixer Name
Zone 01 FC Fan, !- Fan Name
01 FC CC, !- Cooling Coil Name
autosize, !- Maximum Cold Water Flow Rate {m3/s}
0.0, !- Minimum Cold Water Flow Rate {m3/s}
0.001, !- Cooling Convergence Tolerance
01 FC HC, !- Heating Coil Name
autosize, !- Maximum Hot Water Flow Rate {m3/s}
0.0, !- Minimum Hot Water Flow Rate {m3/s}
0.001, !- Heating Convergence Tolerance
Coil:Cooling:Water; !- Cooling Coil Object Type
===============
This listing has already been expanded with connection node name, or you copied the expanded version and changed the connection node name.. The node names may not match.
====================
Later I will try the UnitVentilator instead, I think it will produce the same results as the FourPipeFanCoil without the outside air input. Is this correct?
Actually they are all tsimilar. Univentilator is similar to the temperate you use for the Zone 03 and 04, but have all the dehumidifier, economizer, etc. included. A longer list for input, if I remember correctly. You are mixing the various generation of EPlus input methods and hence make them more difficult to understand.
HVACTemplate was the old Compact format. Uni- is for unitary and is now the packaged system. The examples are up dated to show the latest available functions, such as ConstantFanVariableFlow in three steps, and most of them have VAV in the title.
In the template, you let the program choose the fan type, which will be shown in the expended version of IDF.
The expanded version is what the EPlus program will use for simulation. As far as your problem is concerned, it does not matter which version of zone fan coil you use it will generate problem in the Master zone which has the thermostat transfered to the Primary air loop control.
Thank-you
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> wrote:
>
>
> If you have two pipe fan coil in each zone, you will need seasonal control, and choose the correct thermostat control to match the seasonal value..
> The connection and the master thermostat sharing problem is not resolved by this fan coil change.
> CBVAV, ChangeOver VAV as an independent temperature controlled fresh air loop may help.
> Dr. Li
>
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> From: vieira.jose99@...
> Date: Fri, 15 Apr 2011 12:03:15 +0000
> Subject: [EnergyPlus_Support] Re: Zone FanCoils and an AHU
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Looks like I really need some help.
>
>
>
> Can someone please explain how do you put an AHU for fresh air for various zones and in each zone there is a 2 pipe FanCoil for air temperature control?
>
>
>
> I have been trying to put a AirTerminal:SingleDuct:Uncontrolled and a ZoneHVAC:FourPipeFanCoil in the same zone. The air flow rate on the singleduct:uncontrolled is zero!?. I have both equipments in the same colum in ZoneHVAC:EquipmentList.
>
>
>
> Thank-you
>
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@> wrote:
>
> >
>
> >
>
> > Hi, Vieira
>
> > I have looked at your IDF. It is for an hospital.
>
> > Hospital had different fresh air requirement and filtering requirement for the operating theaters.
>
> > I was involved in the design of the air-conditioning requirement of the hospital building of the Faculty of Medicine in Kuala Lumpur, Malaysia. It was in 1967/9 period. I was not the designer and was in the reviewer capacity for the University.
>
> > I have not been following the advances in this field. If you are designing a new hospital, you may need to look at any new requirements not to mix up the air from different areas of the hospital units.
>
> > That means that more then one AHU unit are required, and each one may be required to have fresh air and return air filtering unit and tighter temperature and humidity control at the feeding duct to the diffuser unit.
>
> >
>
> > Dr. Li
>
> >
>
> >
>
> >
>
> > To: EnergyPlus_Support@xxxxxxxxxxxxxxx
>
> > From: vieira.jose99@
>
> > Date: Thu, 14 Apr 2011 16:20:08 +0000
>
> > Subject: [EnergyPlus_Support] Zone FanCoils and an AHU
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > Hello, first I want to thank all that helped me understand a little better E+ on this previous topic: http://tech.groups.yahoo.com/group/EnergyPlus_Support/message/19759
>
> >
>
> >
>
> >
>
> > Now I have a 74 zone building and want to simulate one AHU to "treat" the minimum new air for occupancy for all the zones and use FanCoils to "treat" the air temperature so that mean air temperature of the zones are 20ºC for winter and 25ºC for Summer.
>
> >
>
> >
>
> >
>
> > What i am tring: Air from the AHU splits to the various zones, then it enters the zone FanCoil, the return air from the zones goes back to the AHU for later on apply recovery mechanisms.
>
> >
>
> >
>
> >
>
> > For now I am only looking to do this on two zones, so that it is easier to correct mistakes, then when it is working, its easier to do copy/paste for the other zones. For now I am also simulating for the summer design day.
>
> >
>
> >
>
> >
>
> > The problem is that the mean air temperature is outragous, it is above 40ºC for the summer design day. There was no return air from the zone to the AHU, the air was being released by the FanCoil relief outlet node, so I hooked that node up to the air mixer, so that it would return to the AHU.
>
> >
>
> >
>
> >
>
> > I have uploaded the .idf to the problem submital section, the link is:
>
> >
>
> >
>
> >
>
> > http://f1.grp.yahoofs.com/v1/ABqnTWqT74N-28mPIl7kRupySkocrpNc68HOk3a6kHyyGzAmoXDeVi-g1ZaLd_Xwt1650MFZVHq1eZm43mA1RYZJNQxC15tMDPG-/_Problem_Submittals/Sim1_sem_recuperacoes_duas_zonas.zip
>
> >
>
> >
>
> >
>
> > I have put two other zones with the FanCoil HVAC template, so I may make comparisions and later on try to modify it.
>
> >
>
> >
>
> >
>
> > The air temperature leaving the AHU must be in the 20/25ºC range, only the FanCoils will warm/cool the zone air.
>
> >
>
> >
>
> >
>
> > Can someone point me in the wright direction? What is it that is not working here?
>
> >
>
> >
>
> >
>
> > Thank-you
>
> >
>
> > Best Regards,
>
> >
>
> > Vieira
>
> >
>
__._,_.___
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.
![]()
__,_._,___
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: vieira.jose99@xxxxxxxxx
Date: Fri, 15 Apr 2011 14:58:43 +0000
Subject: [EnergyPlus_Support] Re: Zone FanCoils and an AHU
Sorry, I made a mistake in the question, I mean 4pipe fan coil and not 2 pipe fan coil.
I am now trying to connect the AHU directly to the zone and the 4PipeFanCoil also directly to the zone. Just having a bit of trouble to put no outdoor air from the FanCoil, I just want fresh air from the AHU. So now I have two zone air inputs and one exhaust and return node. This does not make sense. See my comments in the mail.
HVACTemplate:Zone:FanCoil,
04, !- Zone Name
04 Thermostat, !- Template Thermostat Name
autosize, !- Supply Air Maximum Flow Rate {m3/s}
, !- Zone Heating Sizing Factor
, !- Zone Cooling Sizing Factor
Flow/Zone, !- Outdoor Air Method, !- Outdoor Air Flow Rate per Person {m3/s}
0.001388889, !- Outdoor Air Flow Rate per Zone Floor Area {m3/s-m2}
0.0, !- Outdoor Air Flow Rate per Zone {m3/s}
On, !- System Availability Schedule Name
0.7, !- Supply Fan Total Efficiency
75, !- Supply Fan Delta Pressure {Pa}
0.9, !- Supply Fan Motor Efficiency
1, !- Supply Fan Motor in Air Stream Fraction
ChilledWater, !- Cooling Coil Type
, !- Cooling Coil Availability Schedule Name
12.5, !- Cooling Coil Design Setpoint {C}
HotWater, !- Heating Coil Type
, !- Heating Coil Availability Schedule Name
50; !- Heating Coil Design Setpoint {C}
=================
The above will be expanded to one similar to the that below with program generated node names.
===========================
Zone 01 FC, !- Name
On, !- Availability Schedule Name
ConstantFanVariableFlow, !- Capacity Control Method
autosize, !- Maximum Supply Air Flow Rate {m3/s}
0.33, !- Low Speed Supply Air Flow Ratio
0.66, !- Medium Speed Supply Air Flow Ratio
autosize, !- Maximum Outdoor Air Flow Rate {m3/s}
10101, !- Outside Air Schedule Name
FC 01 return node, !- Air Inlet Node Name
zone 01 inlet node, !- Air Outlet Node Name
FC 01 inlet node, !- Outdoor Air Node Name
FC 01 relief outlet node,!- Air Relief Node Name
01 FC OA Mixer, !- Outdoor Air Mixer Name
Zone 01 FC Fan, !- Fan Name
01 FC CC, !- Cooling Coil Name
autosize, !- Maximum Cold Water Flow Rate {m3/s}
0.0, !- Minimum Cold Water Flow Rate {m3/s}
0.001, !- Cooling Convergence Tolerance
01 FC HC, !- Heating Coil Name
autosize, !- Maximum Hot Water Flow Rate {m3/s}
0.0, !- Minimum Hot Water Flow Rate {m3/s}
0.001, !- Heating Convergence Tolerance
Coil:Cooling:Water; !- Cooling Coil Object Type
===============
This listing has already been expanded with connection node name, or you copied the expanded version and changed the connection node name.. The node names may not match.
====================
Later I will try the UnitVentilator instead, I think it will produce the same results as the FourPipeFanCoil without the outside air input. Is this correct?
Actually they are all tsimilar. Univentilator is similar to the temperate you use for the Zone 03 and 04, but have all the dehumidifier, economizer, etc. included. A longer list for input, if I remember correctly. You are mixing the various generation of EPlus input methods and hence make them more difficult to understand.
HVACTemplate was the old Compact format. Uni- is for unitary and is now the packaged system. The examples are up dated to show the latest available functions, such as ConstantFanVariableFlow in three steps, and most of them have VAV in the title.
In the template, you let the program choose the fan type, which will be shown in the expended version of IDF.
The expanded version is what the EPlus program will use for simulation. As far as your problem is concerned, it does not matter which version of zone fan coil you use it will generate problem in the Master zone which has the thermostat transfered to the Primary air loop control.
Thank-you
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> wrote:
>
>
> If you have two pipe fan coil in each zone, you will need seasonal control, and choose the correct thermostat control to match the seasonal value..
> The connection and the master thermostat sharing problem is not resolved by this fan coil change.
> CBVAV, ChangeOver VAV as an independent temperature controlled fresh air loop may help.
> Dr. Li
>
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> From: vieira.jose99@...
> Date: Fri, 15 Apr 2011 12:03:15 +0000
> Subject: [EnergyPlus_Support] Re: Zone FanCoils and an AHU
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Looks like I really need some help.
>
>
>
> Can someone please explain how do you put an AHU for fresh air for various zones and in each zone there is a 2 pipe FanCoil for air temperature control?
>
>
>
> I have been trying to put a AirTerminal:SingleDuct:Uncontrolled and a ZoneHVAC:FourPipeFanCoil in the same zone. The air flow rate on the singleduct:uncontrolled is zero!?. I have both equipments in the same colum in ZoneHVAC:EquipmentList.
>
>
>
> Thank-you
>
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@> wrote:
>
> >
>
> >
>
> > Hi, Vieira
>
> > I have looked at your IDF. It is for an hospital.
>
> > Hospital had different fresh air requirement and filtering requirement for the operating theaters.
>
> > I was involved in the design of the air-conditioning requirement of the hospital building of the Faculty of Medicine in Kuala Lumpur, Malaysia. It was in 1967/9 period. I was not the designer and was in the reviewer capacity for the University.
>
> > I have not been following the advances in this field. If you are designing a new hospital, you may need to look at any new requirements not to mix up the air from different areas of the hospital units.
>
> > That means that more then one AHU unit are required, and each one may be required to have fresh air and return air filtering unit and tighter temperature and humidity control at the feeding duct to the diffuser unit.
>
> >
>
> > Dr. Li
>
> >
>
> >
>
> >
>
> > To: EnergyPlus_Support@xxxxxxxxxxxxxxx
>
> > From: vieira.jose99@
>
> > Date: Thu, 14 Apr 2011 16:20:08 +0000
>
> > Subject: [EnergyPlus_Support] Zone FanCoils and an AHU
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > Hello, first I want to thank all that helped me understand a little better E+ on this previous topic: http://tech.groups.yahoo.com/group/EnergyPlus_Support/message/19759
>
> >
>
> >
>
> >
>
> > Now I have a 74 zone building and want to simulate one AHU to "treat" the minimum new air for occupancy for all the zones and use FanCoils to "treat" the air temperature so that mean air temperature of the zones are 20ºC for winter and 25ºC for Summer.
>
> >
>
> >
>
> >
>
> > What i am tring: Air from the AHU splits to the various zones, then it enters the zone FanCoil, the return air from the zones goes back to the AHU for later on apply recovery mechanisms.
>
> >
>
> >
>
> >
>
> > For now I am only looking to do this on two zones, so that it is easier to correct mistakes, then when it is working, its easier to do copy/paste for the other zones. For now I am also simulating for the summer design day.
>
> >
>
> >
>
> >
>
> > The problem is that the mean air temperature is outragous, it is above 40ºC for the summer design day. There was no return air from the zone to the AHU, the air was being released by the FanCoil relief outlet node, so I hooked that node up to the air mixer, so that it would return to the AHU.
>
> >
>
> >
>
> >
>
> > I have uploaded the .idf to the problem submital section, the link is:
>
> >
>
> >
>
> >
>
> > http://f1.grp.yahoofs.com/v1/ABqnTWqT74N-28mPIl7kRupySkocrpNc68HOk3a6kHyyGzAmoXDeVi-g1ZaLd_Xwt1650MFZVHq1eZm43mA1RYZJNQxC15tMDPG-/_Problem_Submittals/Sim1_sem_recuperacoes_duas_zonas.zip
>
> >
>
> >
>
> >
>
> > I have put two other zones with the FanCoil HVAC template, so I may make comparisions and later on try to modify it.
>
> >
>
> >
>
> >
>
> > The air temperature leaving the AHU must be in the 20/25ºC range, only the FanCoils will warm/cool the zone air.
>
> >
>
> >
>
> >
>
> > Can someone point me in the wright direction? What is it that is not working here?
>
> >
>
> >
>
> >
>
> > Thank-you
>
> >
>
> > Best Regards,
>
> >
>
> > Vieira
>
> >
>
__._,_.___
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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