As James said, there are a couple of things that can lead to this:
** Severe ** FindRootSimpleController: Controller error for controller = "AIR LOOP_1FLOOR AHU/1 HEATING COIL CONTROLLER"
** ~~~ ** Environment=ENNSMARTBUILDING, at Simulation time=12/15 01:30 - 02:00
** ~~~ ** Controller function is inconsistent with user specified controller action = "" action
** ~~~ ** Actuator will be set to maximum action
** ~~~ ** Controller control type=Temperature
** ~~~ ** Controller temperature setpoint = 14.00 [C]
** ~~~ ** Controller sensed temperature = 13.92 [C]
** ~~~ ** Controller actuator mass flow rate set to 1.39 [kg/s]
** ~~~ ** Controller actuator temperature = 11.82 [C]
Here you can see that the setpoint on the exit of the coil requires the coil to "cool" from 13.92 deg C to the 14 deg C setpoint (impossible, unless it's heating, in which case the action of the actuator is the wrong way around). This situation occurs when the entering air is colder than the cooling coil setpoint. It is quite common. The simulation correctly sets the actuator to a max/min position (in this case fully closed - no cooling) and continues.
Be aware of frost damage at really low entry temps (less than 4 + tolerance) and perhaps think of building in a preheating coil for this case.
As a side note, the error file showed some other issues, which you should try and understand one at a time.
One which I know and particularly love is:
HeatExchanger:AirToAir:SensibleAndLatent "AIR LOOP_3FLOOR AHU/1 HEAT RECOVERY DEVICE": Average air volume flow rate is <50% or >130% warning continues. Air flow rate ratio statistics follow.
Basically, no manufacturer has performance data for heat recovery devices where the difference of supply and exhaust air streams is less than 50% or more 130%. EnergyPlus is the only software I know which even handles unbalanced and non-100% flowrates it it's model for the HX. That is why you specify sensible and latent efficiencies at both 100% and 75% design flow rates. Klingleberger (thermal wheel) was one manufacturer which could give me this data for various AHU sizes. A couple of trends were apparent.
1) efficiencies drop off dramatically as the equipment size reduces (20000m3/h @ 80% sens.eff. to 10000m3/h @ 50%) which is basically due to the geometry ratios fo round wheel in square channel.
2) unbalanced flows (like less exhaust) also has a major impact
3) latent efficiencies are in the range of 35% for their thermal wheels.
So be aware that when you exceed the valid ranges of the model for unbalanced flows, there may be rubbish comming out... actually it may be quite accurate, but is as far as I'm aware experimentally unverified.
On 29.10.2013, at 15:40, "Yan, Ying" <yiy11005@...> wrote:
Hello Jill,
Thank you so much for your answer. Actually I used the IDFVersionUpdater.exe to update the IDF file obtained from DesignBuilder to 8.0.0. There is no warning message. I do not know whether the error that the "Controller function is inconsistent with user specified control action = "" action" is caused by any other reasons or not. Can you give me some suggestions?
----------------------------------------Best Regards
Ying Yan
Graduate StudentElectrical & Computer EngineeringSchool of EngineeringUniversity of Connecticut
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [EnergyPlus_Support@xxxxxxxxxxxxxxx] on behalf of Jill Dalglish [jill.dalglish@...]
Sent: Tuesday, October 29, 2013 9:51 AM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: [EnergyPlus_Support] Re: Controller function error
JillGood luck,4. If you know your IDF version is 8.0 or the latest version, I would just download and install the latest version of EnergyPlus, then they should match.3. You can try to trick the program into getting rid of this warning by just changing the version in the IDF file in a text editor, but this is merely cosmetic.2. There is a "Version" object in your IDF file. If that doesn't match, you will usually get this warning.1. If the EPLaunch version doesn't match the IDF file version, there is usually a warning saying so.Hello Ying Yan,A few things that may help if you haven't figured this out already.