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

How to use EMS to control natural ventilation depending of indoor CO2 concentration?

asked 2019-01-23 00:50:15 -0600

qiulu gravatar image

updated 2019-01-23 09:47:26 -0600

Hello, I would like to do is when the CO2 reaches 1000 ppm, the window will open. And I used EMS set the C02 concentration of the zone as a sensor. However, there is always an error: "unique key name not found" in the file, showing on the following. I was wondering if anyone could tell me how to create a unique name in "EnergyManagementSystem: Sensor". Thanks in advance.

 ** Severe  ** Invalid Output:Variable or Output:Meter Index Key Name =CARBON DIOXIDE
   **   ~~~   ** For Output:Variable or Output:Meter = ZONE AIR CO2 CONCENTRATION
   **   ~~~   ** Entered in EnergyManagementSystem:Sensor=CO2_CONC
   **   ~~~   ** Unique Key Name not found.
   **  Fatal  ** Errors found in processing Energy Management System input. Preceding condition causes termination.
edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted

answered 2019-01-23 14:21:30 -0600

For the ZONE AIR CO2 CONCENTRATION output variable you are using, the key name should be the name of the zone object that you want the CO2 concentration of. You've set this to CARBON DIOXIDE, which doesn't seem to be an option and causes EnergyPlus to write out this Unique Key Name not found. error message. This means that your CO2_CONC sensor will only be set to the CO2 concentration in one zone. If you want to get CO2 in multiple zones, you'll need to create a unique sensor for each zone.

edit flag offensive delete link more


Thank you so much. It runs.

qiulu gravatar imageqiulu ( 2019-01-23 19:54:24 -0600 )edit

@qiulu great! If you think the answer addresses your issue, then let others know by clicking on the check mark on the left of the answer.

Aaron Boranian gravatar imageAaron Boranian ( 2019-01-24 11:15:35 -0600 )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


Asked: 2019-01-23 00:50:15 -0600

Seen: 89 times

Last updated: Jan 23