2.1.2 Coordination with changes made to setpoints via the System Schedules and Setpoints dialog
The values in these profiles are presently (in VE 2012) coordinated with night/weekend/holiday set-back/set-up schedules for zone temperature setpoints via hard-wired temperature offsets in IP units, such as setpoint +1°F and setpoint -1°F. The offset are the fundamental driver of airside controls sequencing.
The exact profile names are critical to this function, as they are used both by the System Schedules and Setpoints dialog to keep track of alternate profile sets and by the profile import procedure to determine which are present already.
Some HVAC profile application references within the controllers have been revised over time to improve control sequencing (e.g., some have been switched from CP3 to CP4 or similar). There are also a few new applications of these profiles to specific controls and systems subsequently added. For example, the profile named “HVAC CP4 - Cooling (Midband: Sys 3–8 VAV airflow; Sys 9 FCU Clg Coil SAT)” is now also used as to provide a timed midband for the zone-temperature based reset of the target mixed-air temperature at the outside air economizer damper set. The name of the profile does not suggest this. Unfortunately, within the current scheme, the names of the HVAC profiles cannot be changed without breaking their functionality. The current HVAC profile names are therefore occasionally a bit confusing.
In a future release, the HVAC and SYS profile names will be simplified in keeping with the table above to clarify relationships to setpoints and other specific functions, such as how a particular profile is used to determine the operation of a particular component for a selected setback strategy in the unoccupied hours. Until then, that table is a handy reference. It also shows which HVAC profiles are redundant: CP1/2, CP3/6, HP2/3, and PP1/2/3.
These HVAC profiles will, in a subsequent release, be replaced altogether with a more transparent and flexible scheme that supports both Metric and IP units and provides user-friendly adjustment of the control “throttling range” without need for manually editing control bandwidths and HVAC profiles. Until that functionality is in place, the Appendix following this one describes manual edits for applications wherein a narrower throttling range is required.
The spreadsheet below—best viewed at zoom of about 250%—describes the main applications of the HVAC control profiles (CP1, HP4, and so forth) in controllers for each of the principal nine categories or types of pre-defined HVAC systems in somewhat greater detail.
The spreadsheet below—best viewed at zoom of about 250%—describes the main applications of the HVAC control profiles (CP1, HP4, and so forth) in controllers for each of the principal nine categories or types of pre-defined HVAC systems in somewhat greater detail.