Fundamentally, unmet hours will be due to issues with either capacity or controls. From this basic understanding we can use various avenues to troubleshoot.
Capacity:
Here are some questions to ask when troubleshooting capacity issues:
- Are the loads in the spaces
reasonable and what you expect?
- Are the capacities of the systems serving
these spaces reasonable and what they
should be?
- If the capacities are incorrect, revisit your assumptions or examine the autosizing to ensure it is working correctly
Controls:
If the capacities are as they should be then move on to controls:
- Are the heating/cooling sources actually operating?
- If not, when and under what circumstances are they off? Every day? Evenings only? Summer only?
- If they are operating, is the energy actually reaching or being removed from the space? (Is the damper open?)
- What devices/sequences/limits/etc could be causing this.
- If the devices are working correctly are the temperatures of the loops/fluids as they should be? What controls these temperatures in your model?
The particular methods used to answer these questions will depend on the software being used and may be a combination of standard or custom reporting.
