CBECC-Com Issue - Output Forms

[GoogleCodeExporter]

Version = 2013_3_653

Category = Output Forms

Issue Summary:
List the steps taken to produce the error. For example:
      1. step 1 – open the file
      2. step 2 – click calculate
      3. step 3 – software produces error message
      4. step 4 – increase all of the COOLING coil capacities to 56,000 Btu/h
      5. step 5 – click calculate
      6. step 6 – software produces error message:
It seems to me that the htg & clg unmet load hours are reported backwards…why 
would increasing the COOLING capacity decrease the HEATING unmet load hrs?

Original issue reported on code.google.com by f.le...@gmail.com on 5 Dec 2014 at 9:34

Attachments:

• image001_TH.png
• image002_TH.png

[GoogleCodeExporter]

We’re not sure why increasing the cooling capacity decreases heating unmet 
load hours.  However, I can tell you that your models have some issues that 
should be corrected, and which may or may not be part of the problem.  

First, you have the fans set to variable speed.  For systems of type SZAC and 
SZHP, it is expected that the fan will be ConstantVolume.  Using a variable 
speed fan in these system can have unpredictable results.  There is a warning 
about this configuration in the log file.  

Second, you have no supplemental heat coil.  When the outdoor temperature is 
below the Compressor Lockout OAT, you have no heating.  This is the cause of 
the unmet load hours in heating.  When I added an electric resistance 
supplemental heating coil, the heating unmet load hours were eliminated.  

The development team is investigating some issues related to night cycle 
control and ventilation airflow during night cycling.

Closing issue - see issue 862.

Original comment by rhedr...@archenergy.com on 8 Dec 2014 at 10:18

• Changed state: WontFix