Question-and-Answer Resource for the Building Energy Modeling Community
Get s tarted with the Help page
Ask Your Question

Haohan Sha's profile - activity

2021-09-30 14:27:23 -0600 received badge  Popular Question (source)
2021-06-29 21:57:11 -0600 asked a question GetCoilWaterInletNode: Could not find Coil.

GetCoilWaterInletNode: Could not find Coil. I'm working on the simulation of a ventilated slab and a packaged terminal a

2020-08-04 12:33:50 -0600 asked a question BCVTB and ptolemy 2

BCVTB and ptolemy 2 Before using BCVTB for co-simulation of Matlab and energyplus, must I install Ptolemy 2? Or just ins

2020-08-04 12:27:10 -0600 asked a question BCVTB and Ptolemy2

BCVTB and Ptolemy2 Before using BCVTB for the co-simulation of Energyplus and Matlab, must I install the Ptolemy 2 ? Or

2018-12-14 13:49:18 -0600 commented answer How does the Energyplus calculate the ideal loads?

I changed the authority of the link...now everyone can access to the file.(sorry for the inconvenience before),Thanks fo

2018-12-14 13:46:17 -0600 commented answer How does the Energyplus calculate the ideal loads?

This is the Link, thanks for any help. (maybe this is not your job or EP's problem) link text

2018-12-12 12:50:42 -0600 edited question Mismatch of Air heat balance and inside heat balance.

Mismatch of Air heat balance and inside heat balance. Hello Everyone! This question is derived from one of my previous

2018-12-11 15:26:41 -0600 commented answer How does the Energyplus calculate the ideal loads?

This is the Link, thanks for any help. (maybe this is not your job or EP's problem) link text

2018-12-11 15:26:41 -0600 received badge  Commentator
2018-12-11 11:05:36 -0600 commented answer How does the Energyplus calculate the ideal loads?

A mid floor, the material is concrete. just like drawing two smaller zones and putting them together. (of course I match

2018-12-10 18:57:07 -0600 marked best answer How to set opening factors correctly?

For modelling cooling effects of natural ventilation in an atrium, I use the airflow network in energyplus to simulate the natural ventilation. To control the conditions and calculate the change of cooling loads, I use the HVAC template Zone: Ideal Load Air system, and fix indoor temperature in 21 degree.

To control the natural ventilation, I use temperature as Ventilation control mode, and in the Ventilation Control Zone temperature setpoint schedule, I use 20.999 degree. Then, in the indoor and outdoor temperature difference lower limit for maximum venting open factor and upper limit, I set 9 and 9.001 to ensure the openings to be opened in 12-21 degree and opening factors in only 0 and 1.

However, I found the opening factors still have some values less than 1.0, like 0.5, why?

there is my filelink text and resultslink text

Thanks

2018-12-10 18:57:04 -0600 answered a question How to set opening factors correctly?

This is because I set the Output:variable in the hourly, and energyplus will automatically calculate the average of open

2018-12-10 15:38:22 -0600 edited question Mismatch of Air heat balance and inside heat balance.

Mismatch of Air heat balance and inside heat balance. Hello Everyone! This question is derived from one of my previous

2018-12-10 12:13:04 -0600 asked a question Mismatch of Air heat balance and inside heat balance.

Mismatch of Air heat balance and inside heat balance. Hello Everyone! This question is derived from one of my previous

2018-12-10 11:14:47 -0600 answered a question Relation of System Air Heat Transfer Rate and Sensible Cooling Rate of Coil

The unclear results always a problem for the user of energyplus. The problem you described may have different reasons,

2018-12-09 19:37:46 -0600 edited question How does the Energyplus calculate the ideal loads?

How does the Energyplus calculate the ideal loads? Hello, I check the engineering reference, but there is no clear equat

2018-12-09 19:09:36 -0600 edited question How does the Energyplus calculate the ideal loads?

How does the Energyplus calculate the ideal loads? Hello, I check the engineering reference, but there is no clear equat

2018-12-09 17:30:08 -0600 commented answer How does the Energyplus calculate the ideal loads?

Yes, I think this is a good way to show all the Zone Thermal Load. And after dividing, Zone Air Heat Balance Surface Co

2018-12-09 15:00:11 -0600 commented answer How does the Energyplus calculate the ideal loads?

Yes. Basically, the air heat balance system air transfer rate = the cooling load, and above variables are parts of the t

2018-12-03 21:46:23 -0600 asked a question How does the Energyplus calculate the ideal loads?

How does the Energyplus calculate the ideal loads? Hello, I check the engineering reference, but there is no clear equat

2018-12-03 10:29:17 -0600 received badge  Teacher (source)
2018-12-03 09:42:54 -0600 answered a question Question for the Energyplus example file:AirflowNetwork_Multizone_HorizontalOpening

OK This is a summary from Jason DeGraw's answer. The regular AFN model is based on pressure and temperature difference

2018-12-03 09:24:08 -0600 marked best answer How to define a pretty high thermal zone?

Hello! I'm modelling a large atrium with natural ventilation to test the cooling effects of the natural ventilation. For this atrium, to prevent the smoke spreading in fire, it sets a floor in the middle and connects upper part with lower part by some large horizontal openings. As shown in the picture. image description

For this problem, as the I/O reference mentioned, it cannot use the airflow network, because it cannot calculate the temperature stratification. So, it needs to use a Roomair:node: airflowNetwork. However,there is a confusion.

How can I define this space? If I define this atrium as a single zone and use Roomair:node to simulate temperature stratification, it will ignore the effects of floor slab in middle. But If I define it as two zones, as mentioned in the reference, it cannot calculate buoyant effects between these two zones correctly. Any suggestions are very helpful.

2018-12-02 20:50:03 -0600 marked best answer Question for the Energyplus example file:AirflowNetwork_Multizone_HorizontalOpening

Hello Everyone! I am confused by the description in the I/O reference and the example file of the horizontal openings. On the Page 1041 of the I/O reference, it is said:

Cannot do or restricted: Air circulation and/or air temperature stratification within a thermal zone. For example, you should not try to divide a high space, such as an atrium, into subzones separated by artificial horizontal surfaces that have cracks or openings with the expectation that AirflowNetwork will give you a realistic temperature in each subzone and/or a realistic air flow between subzones.

However, in the example file, AirflowNetwork_Multizone_HorizontalOpening, it creates a large space and divide it into two zones with a large horizontal opening in the middle. As it mentioned, if the AFN cannot calculate the temperature stratification simply, how can this example file get correct result?

2018-12-02 20:50:02 -0600 commented answer Question for the Energyplus example file:AirflowNetwork_Multizone_HorizontalOpening

By the way, in the part of RoomAirflow network model, if it needs to connect nodes in a single zone, linkage such as cra

2018-12-02 20:42:05 -0600 commented answer Question for the Energyplus example file:AirflowNetwork_Multizone_HorizontalOpening

This explanation is more reasonable. I checked the RoomAir Model parts in the I/O reference, it said that the airflow in

2018-12-02 20:19:29 -0600 commented answer Question for the Energyplus example file:AirflowNetwork_Multizone_HorizontalOpening

I thought of this situation before. But I think the description is ambiguous. If two vertical spaces can be connected b

2018-12-02 16:09:53 -0600 edited question Question for the Energyplus example file:AirflowNetwork_Multizone_HorizontalOpening

Question for the Energyplus example file:AirflowNetwork_Multizone_HorizontalOpening Hello Everyone! I am confused by the

2018-12-02 16:09:19 -0600 asked a question Question for the Energyplus example file:AirflowNetwork_Multizone_HorizontalOpening

Question for the Energyplus example file:AirflowNetwork_Multizone_HorizontalOpening Hello Everyone! I am confused by the

2018-12-02 12:33:58 -0600 answered a question How to define a good strategy for natural ventilation with Airflownetwork(AFN) in Energyplus?

Your description is too ambiguous. You should show more details...This is a simple answer, and may be not correct. As yo

2018-12-01 16:31:31 -0600 edited question How to define a pretty high thermal zone?

Questions for Airflow Network and Roomair:node: airflowNetwork Hello! I'm modelling a large atrium with natural ventilat

2018-12-01 16:31:23 -0600 edited question How to define a pretty high thermal zone?

Questions for Airflow Network and Roomair:node: airflowNetwork Hello! I'm modelling a large atrium with natural ventilat

2018-11-28 11:09:47 -0600 asked a question How to define a pretty high thermal zone?

Questions for Airflow Network and Roomair:node: airflowNetwork Hello! I'm modelling a large atrium with natural ventilat

2018-11-28 10:43:09 -0600 answered a question How to control inlet air temperature and humidity in Natural ventilation.

For the first question: This problem has been solved by adding a new senor(for example Vent_schedule) in the venting sch

2018-11-28 10:37:39 -0600 marked best answer How to control inlet air temperature and humidity in Natural ventilation.

I'm looking forward modelling the cooling effects caused by natural ventilation. To ensure the indoor thermal comfort, I wish to use natural ventilation only when outside temperature is in 12-21 degree and the outside humidity should be less than 80% on the night(0:00-7:00).

So I have two questions 1. in airflow network, it cannot set outside temperature range and humidity, and So I add a (EMS) to control this. However, how can I control the time?
2. I found that when I use the (EMS), the previous settings in the Airflownetwork:MultiZone:Zone do not work. For example, although I set the Venting Schedule in Airflownetwork:MultiZone:Zone, when the outside conditions satisfy the conditions in EMS, the Venting Schedule is ignored. How to avoid this?

The code is following.

Thanks for any assistance.

!- =========== ALL OBJECTS IN CLASS: ENERGYMANAGEMENTSYSTEM:SENSOR ===========

EnergyManagementSystem:Sensor, ZoneT, !- Name Thermal Zone: The atrium 1, !- Output:Variable or Output:Meter Index Key Name Site Outdoor Air Drybulb Temperature; !- Output:Variable or Output:Meter Name

!- =========== ALL OBJECTS IN CLASS: ENERGYMANAGEMENTSYSTEM:ACTUATOR ===========

EnergyManagementSystem:Actuator, MyOpenFactor1, !- Name Bottom Vent, !- Actuated Component Unique Name AirFlow Network Window/Door Opening, !- Actuated Component Type Venting Opening Factor; !- Actuated Component Control Type

EnergyManagementSystem:Actuator, MyOpenFactor2, !- Name Top Vent, !- Actuated Component Unique Name AirFlow Network Window/Door Opening, !- Actuated Component Type Venting Opening Factor; !- Actuated Component Control Type

!- =========== ALL OBJECTS IN CLASS: ENERGYMANAGEMENTSYSTEM:PROGRAMCALLINGMANAGER ===========

EnergyManagementSystem:ProgramCallingManager, TControlled Open Factor, !- Name BeginTimestepBeforePredictor, !- EnergyPlus Model Calling Point T_OpeningController; !- Program Name 1

!- =========== ALL OBJECTS IN CLASS: ENERGYMANAGEMENTSYSTEM:PROGRAM ===========

EnergyManagementSystem:Program, T_OpeningController, !- Name , !- Program Line 1 IF ZoneT < 12, !- Program Line 2 SET MyOpenFactor1 = 0.0, !- A4 SET MyOpenFactor2 = 0.0, !- A5 ELSEIF ZoneT > 21, !- A6 SET MyOpenFactor1 = 0.0, !- A7 SET MyOpenFactor2 = 0.0, !- A8 ElSE, !- A9 SET MyOpenFactor1 = 1.0, !- A10 SET MyOpenFactor2 = 1.0, !- A11 ENDIF; !- A12

2018-11-17 21:47:29 -0600 asked a question Natural Ventilation and paradoxical Cooling load

Natural Ventilation and paradoxical Cooling load Hello Everyone! I'm modelling the impact of natural ventilation on the

2018-11-08 15:31:24 -0600 marked best answer Discussion on EMS use in Energyplus on Opening factor Control

When I'm checking the simulation example in the energyplus, I found a EMS problem relating to the opening factor Control. In theEMSAirflowNetworkOpeningControlByHumidity.idf, the example file shows a EMS control to the surface:Zn001:Wall001:Win001 by humidity. At the same time, the example file set a venting availability schedule in the Zone Level to control the Opening time. The Venting schedule is below:

Schedule:Compact,
  VentingSched,            !- Name
  Fraction,                !- Schedule Type Limits Name
  Through: 12/31,          !- Field 1
  For: AllDays,            !- Field 2
  Until:  7:00,1.0,        !- Field 3
  Until: 17:00,0.0,        !- Field 5
  Until: 24:00,1.0;        !- Field 7

The EMS control code is below:

EnergyManagementSystem:Sensor, 
  ZoneRH, !- Name 
  Zone 1 Node, !- Output:Variable or Output:Meter Index Key Name
  System Node Relative Humidity; !- Output:Variable or Output:Meter Name

EnergyManagementSystem:Actuator, 
  MyOpenFactor, !- Name 
  Zn001:Wall001:Win001, !- Actuated Component Unique Name 
  AirFlow Network Window/Door Opening, !- Actuated Component Type 
  Venting Opening Factor; !- Actuated Component Control Type

EnergyManagementSystem:ProgramCallingManager, 
  RH Controlled Open Factor, !- Name 
  BeginTimestepBeforePredictor, !- EnergyPlus Model Calling Point 
  RH_OpeningController; !- Program Name 1

EnergyManagementSystem:Program, 
  RH_OpeningController, !- Name 
  IF ZoneRH < 25, !- Program Line 1 
    SET MyOpenFactor = 0.0, !- Program Line 2
  ELSEIF ZoneRH > 60, !- 
    SET MyOpenFactor = 1.0, !- 
  ELSE, !- 
    SET MyOpenFactor = (ZoneRH - 25) / (60 - 25), !- 
  ENDIF; !-

Then, when I checking the results, I found that the Venting availability Schedule is ignored by applying the EMS, which means users cannot control the opening factors based on time! Did anyone discover this irrational problem? Is this a Bug or error? How can user control the openings with EMS and time?