IES-VE User Forum

I am having a problem in the corridor and lobby unmet hours. I had assigned the propoer heating/cooling setpoints, schedule in the thermal templates and APHVAC systems. When I test the rooms for unmet hours it end up having around 3000-4000 unmet hours. Then I go back to the APhvac systems and changed the airflows and heating/cooling load and re-simulate it again but the additional cooling/heating loads and airflow doesn't reflect to the autocalculation. Do you have any particular solution on these? Thank you.

ah a good old unmet load hours problem.

Is anyone out in the field willing to share their troubleshooting techniques? There are myriad variables and I guess everyone has some trusted techniques for attacking this issue.

Phil

Nothing? nobody has any information on how to successfully eliminate unmet load hours?

Unfortunately there is no one specific reason why you would get unmet hours. It is even more confusing when you get them even with a completely autosized system.

Try interrogating and troubleshooting your model using this guide:

http://www.iesve.com/support/faq/pdf/un ... -hours.pdf

Hope it helps!

Unmet hours ! 🤬

Why do the vista pro unmet hours not match the vista pro report for unmet hours!? I am displaying the results for each room.

The parameters and the throttling parameter are all the same ?

One way I have settled unmet hours for corridors is by assigning the set points to a larger band(ie 60-80) since thermal comfort is not as important. Still a lot of things that could affect it, so you would want to check a specific room for 1 specific day and diagnose through the HVAC system components 1 by 1 to ensure each component is operating properly as well as checking nodes to ensure flow and temps are adjusting in system correctly. How much is the overall discrepancy between them? Are you using autosizing or using proposed design data for calculations?