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

designbuilder fatal error

asked 2021-03-04 05:30:47 -0500

oussama-ka's avatar

hey everyone, it's been quite long trying to understand and solve this error in my designbuilder simulation, if you can help me out and guide to some solutions i'll be thankful, C:\fakepath\errors.PNG

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted

answered 2021-03-04 08:28:31 -0500

updated 2021-03-04 08:29:50 -0500

All of the severe errors are related to the fan operating mode schedule assigned to fans of the VRF terminal units. I'll just paste the portions of the first one below and explain what information they convey:

** Severe ** ZoneHVAC:TerminalUnit:VariableRefrigerantFlow = ETAGE5:BUREAUXNORD VRF INDOOR UNIT
**  ~~~~   ** For fan type = Fan:ConstantVolume
**  ~~~~   ** Fan operating mode must be continuous (fan operating mode schedule values > 0).

Your model has a VRF terminal unit named ETAGE5:BUREAUXNORD VRF INDOOR UNIT that contains a constant volume fan. That constant volume fan has an input field for fan operating mode schedule that requires a schedule with values > 0 to run as a continuous fan.

**  ~~~~   ** Error found in Supply Air Fan Operating Mode Schedule Name = 8:00 - 18:00 7/7
**  ~~~~   ** ...schedule values must be (>0., <=1.)

The name of the input field I mentioned above is Supply Air Fan Operating Mode Schedule, and the name of the schedule assigned to this input field is 8:00 - 18:00 7/7.

In the DesignBuilder user guide section for the VRF Indoor Unit, it mentions that if you do set Fan Type to 2-Constant volume fan then the Supply Air Fan Operating Mode Schedule values are never 0 and the fan operates continuously. My best guess without seeing your model is that the 8:00 - 18:00 7/7 schedule has values of 0. You should change this so that each VRF terminal unit has an "Always On" schedule or something similar where all schedule values are >0 assigned to the Supply Air Fan Operating Mode Schedule input field.

edit flag offensive delete link more


yees, thank you soo much Aaron.

oussama-ka's avatar oussama-ka  ( 2021-03-08 14:50:07 -0500 )edit

Your Answer

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

Add Answer

Training Workshops

Question Tools

1 follower


Asked: 2021-03-04 05:30:47 -0500

Seen: 64 times

Last updated: Mar 04 '21