For some time now, I have been wanting to measure the effect of presence of another zone in the facade and analyze changing the parameters of the zone on the thermal comfort of the main room. In this way, I have noticed the limitations of calculating natural ventilation and the exchange of air between zones, in models with two zones, in honey bee. I tried to solve the limitations of calculating two zones for the parametric simulation of this model through research and questioning. Therefore, I brought the necessary Strings that I thought were suitable and completed the work. But only when I use the Run IDF component, I can enter just one of the sample modes defined in Energy Plus into Honey Bee (For example canât analyze different depths or WWR or Proportions, of facade zone). My goal is to use the strings that I imported from Energy Plus, to occur for example Zone cross mixing, For the Model to OSM component, I can use it to simulate and optimize my variables in Honeybee, parametrically.
Unfortunately, I get errors that I canât continue my work.
I think, defined the correct names of the zones in strings but most errors are about that. Also, I defined ACH but donât have any results of air exchange between zones.
Since unfortunately I am not a professional in Energy Plus, this process and solving errors is difficult for me.
In this project, the Zones donât have HVAC and I want to know about Natural ventilation and airflow exchange between zones and the effects of that on thermal comfort, in part of my project.
Please guide me so that I can fix the problem and do simulations
I also added my files here so that I can get more detailed guidance.
Have you tried using the HB Airflow Network component? Thatâs probably the most detailed way to model air flow between two rooms that honeybee supports.
In any event, if you want to use additional strings like that, make sure that you use the HB Set Identifier component to set the simulation name (aka. identifier) of your honeybee objects to something constant that matches what you put in the additional string.
Hi @chris, Thank you very much for your reply.
The truth is that it is much easier for me to use only the HB Airflow Network in Honeybee, but during the project, I realized that I can calculate natural ventilation in the main room only when I have openings on both sides of the main room, and for now, this limitation of the component even forced me to add a window that I didnât need in the opposite wall of the main room.
This is even though with the test that I did earlier in Designbuilder on the same model and in the condition that I did not add an additional window in the main room, the airflow inside the main room can be observed only with the presence of natural air exchange.
These stages of the work made me doubt the proper performance of the HB Airflow Network component for my model and seek to use additional strings from Energy Plus in addition to using the HB Airflow Network component, which considering that I am an amateur in Energy Plus, It has made the process difficult and problematic for me that I cannot do the simulation work because of the received errors.
I would be grateful if you could inform me more about this so that I can continue my work without adding strings such as Zone cross mixing and I can trust the results of the simulation.
Also, regarding the advice you had regarding using the HB Set Identifier component, from my research of this component, it was related to honeybee objects. However, I used it before adding the strings but the errors persisted and the strings were ignored.
I was able to fix the name error problem with the HB Set Identifier component you suggested.
Another problem I have in the simulation of this project is that despite the inputs I entered for Air change per hour, in every mode I try, the airflow inside the zones always shows zero.
The âZoneVentilation:DesignFlowRateâ seems to be set correctly, except for the input âDelta Temperature Schedule Nameâ, which has probably a constant value of 1 (as the same schedule is also input above). Instead, you should have a constant value of -100 to achieve a continuous flow.
However, I think the problem lies in the âAirflowNetwork:SimulationControlâ, where the simulation of external objects to the AFN depends on the selected control.
According to the E+ Input Output Reference, if the AFN Control is set to âMultiZoneWithoutDistributionâ, any ZoneInfiltration, ZoneVentilation, ZoneMixing and ZoneCrossMixing objects specified in the input data file are not simulated.
I appreciate your time and attention in reviewing the details of my question.
I will consider the things you mentioned.
Just one thing about the advice you had about AirflowNetwork: SimulationControl, yes exactly I used the AFN component in Honeybee and checked the output settings from IDF, MultiZoneWithoutDistribution is included in the settings.
With the definitions that I read about MultiZoneWithDistribution, it is more related to the calculations with the fan in the HVAC system, but for a project similar to this one that does not have HVAC, it may not be suitable; Of course, I am not sure about this. Did I understand correctly?
Yes, youâre right, there is no control that allows for the simultaneous simulation of both AFN objects and simple airflow objects (ZoneInfiltration, ZoneVentilation, ZoneMixing, ZoneCrossMixing, âŚ).
From my understanding, using âMultiZoneWithoutDistributionâ makes the program ignore all simple airflow objects, while âNoMultiZoneOrDistributionâ disables the AFN calculations.
The only way that comes to mind is to keep the current control and use an object from the AFN group, such as the âAirflowNetwork:MultiZone:SpecifiedFlowRateâ, to supply the room with a constant airflow. By calculating the volumetric flow rate needed to achieve the desired ACH, and assigning it to one of the external surfaces of the zone using a new column in âAirflowNetwork:MultiZone:Surfaceâ with a âConstantâ control, you should achieve what you are looking for.
Note that to indicate a flow from the outside to the inside, the value must be negative. You can then visualize the air changes per hour by plotting the output âAFN Zone Ventilation Air Change Rateâ.
