VAV system not meeting setpoints
Hi all
I am new to EnergyPlus, I have a VAV system with reheat to perimeter and a couple of internal zones. After running the model we have found there is currently no heating being done by the reheat coils for any of the VAVs connected to the AHUs. This is causing a unmet hours for some zones with AHUs that service perimeter and internal zones. The AHU’s overheat the space and only keep 1 zone at the heating setpoint.
We are able to reduce the unmet hours by effectively turning off the heating ciol at the AHU and letting the reheat coils heat the zones however this is not desirable. We think it might be an issue with the cooling coil setpoint reset type which is currently set to warmest.
What are the maximum and minimum setpoint temperatures you have on the Setpoint Manager Warmest object? And where have you located the setpoint manager object in the air loop?
Hi Matthew, the max = 18C, min = 10C and the setpoint manager is set to at the supply fan of each AHU. The thermostat temperatures for the office that I am modelling is between 21-24C between 07-18. Cheers
Those values seem reasonable. Perhaps it is not an issue with air-side. Does the sizing on your VAV terminals appear ok, and you've checked the temperature setpoint and availability schedules on the heating loop that supplies them?