[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [EnergyPlus_Support] Setpoint temperatures not achieved in space


Thank you for your response. It does look like the heating is working as I have set the AHU's availability schedule as 'alwayson' and the setpoint schedule as 24/7.
The AHU demand side inlet temperature is equal to the AHU Supply Side Outlet temperature but is incredibly low around 25F. However the AHU Extract Fan Air Outlet temperature (which I am assuming is the return air ??) is reasonable and what you would expect for that space. I just don't understand what is going on at the supply air side to be providing such low temperatures as 20-25F when the setpoint says otherwise.
If you have any other ideas on this please forward my way. I may send my model into help as I am running out of ideas (and time).

Thanks again!


From: Jim Dirkes <jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
To: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Thursday, January 17, 2013 6:00 AM
Subject: RE: [EnergyPlus_Support] Setpoint temperatures not achieved in space

It sounds as though the simulationâ??s heating system is not even operating?.
Have you confirmed that the system is actually delivering hot air / water when it should?  (Normally you would add Output variables for the air loop to confirm this (discharge node, mixed air node, etc.)
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Celia King-Scott
Sent: Wednesday, January 16, 2013 4:20 PM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: [EnergyPlus_Support] Setpoint temperatures not achieved in space
Hi all,

I am modeling a performing art/theater building in Eplus. I am trying to calibrate the simulation to the metered data and therefore am looking at the run period of 12/25 - 12/31 when there is no occupancy and minimal internal loads. However AC system is still running 24/7 (shocking I know). The building is located in CO so during this period the outdoor dry bulb is 17F - 25F. My heating setpoint in the space (AHU with VAV reheat boxes) is 70F. However the zone mean temperatures in the ballroom space is 22F (bascially 5F above outdoor at all times) so obviously the set point is not being met.
I have ramped up the fans and heating coil capacities but am still seeing these extremely low temperatures. I've also tried turning off the OA but the zone temperatures are remaining the same. The only thing that seems to change these temperatures is if i increase the internal load in the space or change the weather file. How can I increase these zone temperatures in the space so that the system is meeting the setpoints without changing the internal load.

I am really baffled by what is going on here and would appreciate any help if possible.
Thank you for your time,



Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx

The primary EnergyPlus web site is found at:

The group web site is:

Attachments are currently allowed but be mindful that not everyone has a high speed connection.  Limit attachments to small files.

EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.

Your email settings: Individual Email|Traditional
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe