[EnergyPlus_Support] RE: RE: Heating Time Setpoint not met

[<adrianchong85@xxxxxxxxx>]

Thank you all for replying. I am modeling a VAV system with 3 AHUs and each of them supplying to many zones. As for sizing parameters I think they are quite reasonable with 14C and 50C for cooling and heating zone supply temp. I also check all the controls and made sure that they are always available to find the source of the problem. 

How do I get the output the system node temperature and node flows in EnergyPlus?? 

So I have been trying to find the source of the problem since then and I have come across several weird instances;

As I decrease the zone heating supply temperature (in zone:sizing), the cooling time setpoint not met increases? I thought zone heating supply temperature is only used to size heating equipment why would it affect zone temperature during cooling?

Another thing is as I increase the sizing factor of the boiler, the heating time setpoint not met actually increases. From my knowledge, increasing sizing factor would increase the boiler's ability to provide heating either through its capacity or flow rate. Does this mean that I am overheating the space?

Regards,

Adrian

---In EnergyPlus_Support@xxxxxxxxxxxxxxx, <fpasserini.tn@...> wrote:

 I have very often problems with setpoint temperatures. The reasons are a lot: among the output variables check system node temperatures and system node flows, heating rates, sizing parameters, if in Sizing:System the "Type of Load to Size on" is "sensible", the properties of the envelope, natural ventilation...

Are you modeling AHUs that supply many zones? 

Are you modeling radiant floors or ceilings? 

With those systems I have often problems. Check how the system is controlled, check the position of the internal source...

Best Regards

---In energyplus_support@xxxxxxxxxxxxxxx, <adrianchong85@...> wrote:

I am currently trying to model a building in energyplus. However, somehow the heating time setpoint is always not met for all hours and the thing is it is not met even when I autosized the boilers, pumps and coils which doesn't make much sense

Cooling time setpoint is pretty low though.

Hence I would like

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