See my comments in red below. There may be other problems.
To: energyplus_support@xxxxxxxxxxxxxxx
From: alvaro.urrutia@xxxxxxxxx
Date: Mon, 17 Oct 2011 13:56:53 -0700
Subject: Re: [EnergyPlus_Support] Severe errors for Fan Power modelling of VAV system
Thanks for quick response.
Your explanaiton make sense, but these errors not occurs when Supply Fan Delta Pressure is set below 500 Pa (defined for VAV system through HVAC templates).
anyway, the most frustrating thing of these errors is the lack of documentation in the large help provided with the software.
Tanks in advance.
From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Monday, October 17, 2011 5:22 PM
Subject: RE: [EnergyPlus_Support] Severe errors for Fan Power modelling of VAV system
__._,_.___
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:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
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.
![]()
__,_._,___
A real design problem created the fan power warning. The command was to increase the fan power to lower the temperature to the setpoint. Hence the fan power went up.
Dr. Li
To: energyplus_support@xxxxxxxxxxxxxxx
From: alvaro.urrutia@xxxxxxxxx
Date: Mon, 17 Oct 2011 13:56:53 -0700
Subject: Re: [EnergyPlus_Support] Severe errors for Fan Power modelling of VAV system
Your explanaiton make sense, but these errors not occurs when Supply Fan Delta Pressure is set below 500 Pa (defined for VAV system through HVAC templates).
This is just a guide line. If you set this number too high, then a user would not know that there is a problem.
I think that something go unexpected in EXPIDF subroutine previous to simulation, perhaps by high Pressure defined in Fan:Variable segment for System:VAV objects.
I do not think so. As the error file indicated, that you have set the cooling setpoint to 11.41°C in Winter at Santiago. The cooling coil may be at that temperature, but you will not run a zone at that temperature. As the coil works between 12 and 18°C, the set point should be higher than 18°C and the zone temperature should be higher still, for cooling.
anyway, the most frustrating thing of these errors is the lack of documentation in the large help provided with the software.
This is the basic design requirement using the the values you entered in the sizing objects and schedules. The error message tells you what was wrong. By the way, you may have problem with heating as well., as a similar note was given.
There are several warning in the I/O ref manual to warn you that the setpoint values for heating and cooling should not cross over, and should not be lower than the source.. That is why I know straight away that the setpoint value was too low.
If you really wanted the setpoint to be 11°C in Winter, you can lower the dhiller temperature. If you make the cooling not available in Winter, the error may also disappear.
Tanks in advance.
From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Monday, October 17, 2011 5:22 PM
Subject: RE: [EnergyPlus_Support] Severe errors for Fan Power modelling of VAV system
In your error file:-
~~~ ** Note: Chilled water coils should be reverse action and the entering chilled
** ~~~ ** water temperature (controller actuator temperature) should be below the setpoint temperature
Your setpoint temperature is too low.
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: alvaro.urrutia@xxxxxxxxx
Date: Mon, 17 Oct 2011 20:08:55 +0000
Subject: [EnergyPlus_Support] Severe errors for Fan Power modelling of VAV system
~~~ ** Note: Chilled water coils should be reverse action and the entering chilled
** ~~~ ** water temperature (controller actuator temperature) should be below the setpoint temperature
Your setpoint temperature is too low.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: alvaro.urrutia@xxxxxxxxx
Date: Mon, 17 Oct 2011 20:08:55 +0000
Subject: [EnergyPlus_Support] Severe errors for Fan Power modelling of VAV system
Dear all:
In a baseline building modeling for LEED EApr2 documentation, I have some troubles with the simulation reports that shows unusually high amounts of severe errors (over 1000); when I try to model System Fan Power according ASHRAE 90.1-2007, G3.1.2.9.
I am concerned if we can be observed by LEED reviewer team about this severe warnings.
Simulation details:
-Baseline model consist of six-levels building for typical office usage (8000m2 area approx.)
-HVAC system type 8, VAV with PFP zones according ASHRAE 90.1-2007 appendix G.
-Energyplus 6.0.0.023 software has been used.
-HVAC systems has been modeled with HVAC templates in this configuration:
-Chilled Water loop with HVACTemplate:Plant:ChilledWaterLoop, Chiller and Cooling Tower
-System-side equipment with HVACTemplate:System:VAV
-Zone-side equipment with HVACTemplate:Zone:VAV:FanPowered
-System Fan Power modeling details:
-Supply Fan Total Efficiency = 0.6
-Supply Fan Delta Pressure = 1495 Pa
-Supply Fan Motor Efficiency = 0.9
-Severe errors details:
When Supply Fan Delta Pressure exceeds 500Pa, simulation error log exposes unusually high amounts of recurrent severe errors like that (over 1000 severe errors):
** Severe ** FindRootSimpleController: Controller error for controller = SYSTEMVAV_DATACENTER COOLING COIL CONTROLLER
** ~~~ ** Environment=SANTIAGO, at Simulation time=01/01 04:30 - 04:35
** ~~~ ** Controller function is inconsistent with user specified controller action = "" action
** ~~~ ** Actuator will be set to maximum action
** ~~~ ** Controller control type=Temperature
** ~~~ ** Controller temperature set point = 11.41 [C]
** ~~~ ** Controller sensed temperature = 12.17 [C]
** ~~~ ** Controller actuator mass flow rate set to 0.70 [kg/s]
** ~~~ ** Controller actuator temperature = 12.20 [C]
** ~~~ ** Note: Chilled water coils should be reverse action and the entering chilled
** ~~~ ** water temperature (controller actuator temperature) should be below the setpoint temperature
** ~~~ ** Note: Hot water coils should be normal action and the entering hot
** ~~~ ** water temperature (controller actuator temperature) should be above the setpoint temperature
Also I tried to reduce Supply Fan Total Efficiency and maintain Supply Fan Delta Pressure less than 500Pa but severe errors also occurred.
Suggestions to reduce this errors or modeling system fan power in a different way?
Any comments will be appreciated....
Regards
Alvaro Urrutia Astorga
Arquitecto.
In a baseline building modeling for LEED EApr2 documentation, I have some troubles with the simulation reports that shows unusually high amounts of severe errors (over 1000); when I try to model System Fan Power according ASHRAE 90.1-2007, G3.1.2.9.
I am concerned if we can be observed by LEED reviewer team about this severe warnings.
Simulation details:
-Baseline model consist of six-levels building for typical office usage (8000m2 area approx.)
-HVAC system type 8, VAV with PFP zones according ASHRAE 90.1-2007 appendix G.
-Energyplus 6.0.0.023 software has been used.
-HVAC systems has been modeled with HVAC templates in this configuration:
-Chilled Water loop with HVACTemplate:Plant:ChilledWaterLoop, Chiller and Cooling Tower
-System-side equipment with HVACTemplate:System:VAV
-Zone-side equipment with HVACTemplate:Zone:VAV:FanPowered
-System Fan Power modeling details:
-Supply Fan Total Efficiency = 0.6
-Supply Fan Delta Pressure = 1495 Pa
-Supply Fan Motor Efficiency = 0.9
-Severe errors details:
When Supply Fan Delta Pressure exceeds 500Pa, simulation error log exposes unusually high amounts of recurrent severe errors like that (over 1000 severe errors):
** Severe ** FindRootSimpleController: Controller error for controller = SYSTEMVAV_DATACENTER COOLING COIL CONTROLLER
** ~~~ ** Environment=SANTIAGO, at Simulation time=01/01 04:30 - 04:35
** ~~~ ** Controller function is inconsistent with user specified controller action = "" action
** ~~~ ** Actuator will be set to maximum action
** ~~~ ** Controller control type=Temperature
** ~~~ ** Controller temperature set point = 11.41 [C]
** ~~~ ** Controller sensed temperature = 12.17 [C]
** ~~~ ** Controller actuator mass flow rate set to 0.70 [kg/s]
** ~~~ ** Controller actuator temperature = 12.20 [C]
** ~~~ ** Note: Chilled water coils should be reverse action and the entering chilled
** ~~~ ** water temperature (controller actuator temperature) should be below the setpoint temperature
** ~~~ ** Note: Hot water coils should be normal action and the entering hot
** ~~~ ** water temperature (controller actuator temperature) should be above the setpoint temperature
Also I tried to reduce Supply Fan Total Efficiency and maintain Supply Fan Delta Pressure less than 500Pa but severe errors also occurred.
Suggestions to reduce this errors or modeling system fan power in a different way?
Any comments will be appreciated....
Regards
Alvaro Urrutia Astorga
Arquitecto.
__._,_.___
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:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
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
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
__,_._,___