In order to provide a full and informative report new functionality has been added into the VE to cater for new variables. These are detailed as follows:
Duct Leakage
Duct leakage can be an important consideration when evaluating a system configuration. The ‘Duct thermal properties’ component contains a user option to specify duct leakage as a percentage of the entering airflow rate that will be leaked. By default, the value for “Duct Leakage rate (%)” is 0%.
Options for specifying the location defines where the air will leak. The following options are available:
· Duct external to the building = leakage to the external environment
· Duct within Return Air Plenum = leakage to the selected return air plenum
· Duct within Supply Air Plenum = leakage to the selected supply air plenum
· Duct within Zone - leakage to the selected HVAC Zone (enabled when zones exist in the ApacheHVAC file)
· Duct within Room - leakage to the selected room
The plenum, room and zone locations can be assigned from a group if appropriate.
Figure 3 - 1 : Duct thermal properties dialog shown with 10% of airflow leaking into the zone where the component is located.
Fan Configuration
The loads reports are now able to report the fan location relative to the AHU cooling coil. The ‘Fan Configuration’ is reported in multiple locations in the system loads reports see Section 5 for more information. The following terminology is used in the reports:
· Fan is downstream of cooling coil = Draw-Through configuration
· Fan is upstream of cooling coil = Blow-Through configuration
For any system wherein either one or both of the two required links (AHU Cooling Coil and Supply fan) is not present or the flow-path node configuration makes it impossible to determine the relative location of these two components, the Fan configuration row in the report will read “undetermined”.
Further details about the fan component can be found in ApacheHVAC User Guide part B.
