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
G3.1.2.9. and procedure proposed by James V Dirkes II, PE in a previous post
(pro-rating fan power to supply/ret?urn fans per 90.1-2007?).****

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 = Reverse 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