RE: [EnergyPlus_Support] Extremely high user design load for heating for HVAC system 3

[YuanLu Li <yli006@xxxxxxxxxxx>]

I have traced the zones using the OpenStudio.

Your IDF have two severe errors referring to two zones.

** Severe ** Sizing: Coil:Cooling:DX:SingleSpeed "UNITARYSYSTEM1 COOLING COIL": Rated air volume flow rate per watt of rated total cooling capacity is out of range.

** ~~~ ** Min Rated Vol Flow Per Watt=[4.027E-005], Rated Vol Flow Per Watt=[6.111E-005], Max Rated Vol Flow Per Watt=[6.041E-005]. See Input-Output Reference Manual for valid range.
============
The message warns that the vol flow per Watt is too large.

I traced the cause to the following in the System:unitoary:

0.708, !- Supply Fan Maximum Flow Rate {m3/s}

is within range.

0.8024, !- Supply Fan Maximum Flow Rate {m3/s}

is out of range.

Therefore you had sever errors for Zones 1 and 2.
====================
According to the simulation result, the building is comfortable without any cooling or heating.   The building ground temperature is regulating the zone mean temperature.

 Dr. Li  


To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: zqianmin@xxxxxxxxx
Date: Fri, 8 Jul 2011 11:15:16 -0700
Subject: [EnergyPlus_Support] Extremely high user design load for heating for HVAC system 3


Hello All,
First I want some help to better understand the result. Under HVAC Summary, for both heating, cooling, and airflow rate, there are two objects, one is calculated design, one is user design. I'm not that understand the difference between these two. Is there any relation between these two? Which document should I read to get know these things?