Question-and-Answer Resource for the Building Energy Modeling Community
Get s tarted with the Help page
Ask Your Question
2

Getting started with ventilation simulation in OS

asked 2017-04-26 22:09:03 -0500

rtsuchiya gravatar image

Dear all,

I am a (very new) research staff in agricultural engineering field and want to simulate energy balance of greenhouses.

Currently, I am trying to model very simple greenhouse with natural ventilation. With OpenStudio, I set natural ventilation to "Zone Equipment" in "Thermal Zones" and ran the model. However, it seems that there was no ventilation as it is shown in results (I checked the Zone Ventilation Total Heat Loss Energy).

The description of the model is like; with one thermal zone and two windows, using weather data downloaded from E+ webpage (Tokyo), without anything set in the space.

I would like to know what is the possible solution for this.

Best regards,

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted
2

answered 2017-04-27 00:16:25 -0500

updated 2017-04-27 00:20:41 -0500

@rtsuchiya, you aren't doing anything wrong, you are hitting this issue which effects Zone Ventilation Design Flow Rate when there isn't another piece of zone equipment on the zone. If you check `Simple Ventilation' in the tabular output it probably also shows 0 (in addition to what you are seeing in time series results).

You should be able to work around this by also adding a Fan Zone Exhaust object with a max flow rate of 0 (so it doesn't do anything). Let me know if that doesn't work. In test I just did I had fan after the zone ventilation but it may be fine in either order (but I'm not sure).

edit flag offensive delete link more

Comments

Thank you for your advise, I tried. However, it seems the problem was not solved yet.

Result shown in the Table (Zone Equipment Detail) is like;

Object Sizing Sizing Units Description Value Value Units Count

OS:Fan:ZoneExhaust 0.00 cfm Fan Efficiency 0.60 fraction

OS:ZoneVentilation:DesignFlowRate

(Ventilation is still blank. Outdoor Air is too.)

For Natural Ventilation, I chose the schedule whose type is OnOff and set the value 1 all the day long.

Do I need to provide you more information?

rtsuchiya gravatar image rtsuchiya  ( 2017-04-27 02:06:46 -0500 )edit

Zone Equipment Detail, Air Loops Detail, and Plant Loops Detail sections of the OpenStuido Results are meant to give a quick overview of model elements across loops and zones. For many objects you get additional detail beyond the object name, but for some you just get the name. That doesn't mean there isn't more information. Also these tables just echo back input data.

Zone Ventilation Design Flow Rate is one of the objets that just reports the name. To see if it is functioning in the model look at the "Avg. Simple Ventilation" column of "Outdoor Air Table"

David Goldwasser gravatar image David Goldwasser  ( 2017-04-27 09:46:10 -0500 )edit

Thank you. I understood that those variables are just echo. But, when checking "Avg. Simple Ventilation", the value is still 0. This means the ventilation doesn't work... I am afraid that I made a simple mistake in my setting. I will check more carefully later, but if you still have more tips, I'd like to know that. Thank you very much for your kind comment.

rtsuchiya gravatar image rtsuchiya  ( 2017-04-27 23:20:11 -0500 )edit

In addition, the term "None" is shown in the far left column of the table. Does this mean I missed inputting something?

rtsuchiya gravatar image rtsuchiya  ( 2017-04-27 23:28:29 -0500 )edit

If you post a link to the file or email it to OpenStudio@nrel.gov I can take a look.

David Goldwasser gravatar image David Goldwasser  ( 2017-04-28 08:51:59 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

 

Question Tools

1 follower

Stats

Asked: 2017-04-26 22:09:03 -0500

Seen: 582 times

Last updated: Apr 27 '17