Can I add a humidity control in Natural ventilation?

asked 2018-10-31 15:09:03 -0500

Haohan Sha
279 ●6

Hello everyone! I'm modelling a single zone and want to test the natural ventilation effects on the reduction of cooling demand. Now, I use the simple tool in the Energyplus of Zoneventilation:Wind and stackopenarea, and I want to add a humidity control of the natural ventilation, since nobody will open the door when it is raining outside. But I cannot find relevant control method in the Energyplus.

By the way, this zone is pretty high, except the Zoneventilation:Wind and stackopenarea, is there any other method that can calculate wind effects and stack effect together in the energyplus?

Thanks for any suggestions!

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answered 2018-10-31 16:16:32 -0500

Aaron Boranian

13830 ●76 ●24 http://bigladdersoftware.com/

If you're using the ZoneVentilation:WindandStackOpenArea object, its control fields for when window openings occur are a schedule, min / max outdoor air temperatures, and max outdoor air wind speed.

Another option to account for wind and stack effects is to use Airflow Network objects instead of the Wind and Stack Open Area Ventilation object. However, this adds lots of complexity to the input file, because this asks EnergyPlus to calculate air pressure differences throughout the model every timestep and calculate the resulting air flow. I'll also note that Ventilation Control Modes for the Airflow Network look at temperature, enthalpy, ASHRAE Standard 55 Adaptive Comfort Requirements, or CEN15251 Adaptive Comfort Requirements -- not absolute or relative humidity.

If you want to incorporate controls based on outdoor air humidity, I would recommend that you keep using the Wind and Stack Open Area Ventilation object and add EMS objects to your input file to define your custom controls logic. Refer to the EMS Application Guide for more information.

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I checked the guide of airflow network model in the energyplus(I/O reference), it only mentions the wind effects and nothing with calculation of stack effect. Do you mean if I use the AFN model, for example, adding 1 indoor air node, and 1 external node, this model will automatically calculate the stack effect and wind effects between this two nodes?

After using the AFN model in the energyplus, and than I add a EMS objects to control the air humidity in this model, so I can control all the things?

Thanks a lot Regards