2 HVAC controller profiles relative to setpoints entered in the System Schedules dialog
SYS Cooling Setpoint = Timed cooling setpoint (during occ. + start-up & after hours) and setback (unoccupied hours)
SYS Heating Setpoint = Timed heating setpoint (during occ. + start-up & after hours) and setback (unoccupied hours)
SYS Plant Profile = On-off modulating profile denoting times—e.g., occupied or “opening hours”—for which the normal daytime setpoints should be fully met. This excludes morning start-up and after-hours operation when the set-points for occupied hours are in play, but may not yet be achieved.
CP1 = Cooling SP (150 F = “off”)
HP1 = Heating SP -1°F
EP1 = Occupied hrs; or all hours when setback strategy set to any not labeled “OA off”.
PP1 , PP2, and PP3 = Occ. hrs. only if OA min set Off in unocc. hrs.; Occ. + start-up & after hrs. if OA min On, but fans cycling in unocc. hrs.; All hrs. if OA min is On 24-hours, per EP1.
CP2 = Cooling SP (150 F = “off”)
HP2 = Heating SP (40 F = “off”)
CP3 = Cooling SP +1°F
HP3 = Heating SP (40 F = “off”)
CP4 = Cooling SP -1°F
HP4 = Heating SP +1°F
CP5 = Cooling SP -1°F (150 F = “off”)
HP5 = Heating SP +1°F (40 F = “off”)
CP6 = Cooling SP +1°F
HP6
Occupied hours
(all hrs. when Fan not off or cycling)
= Midpoint between Heating & Cooling setpoints
Unoccupied hours
= Heating SP +2°F
(40 F = “off” in unoccupied hours)
PP4 = Same as PP1, except when garage fan strategy set to “Setback during unocc. Times" wherein % is applied to PP4 for all unoccupied hours (regardless of setback vs. 24-hr cond. to occ. setpoints setting for all other profiles).
CP7
Occupied hours
(all hrs. when Fan not off or cycling)
= Midpoint between Cooling & Heating setpoints
Unoccupied hours
= Cooling SP -1°F
(150 F = “off” in unoccupied hours)
HP7 = Heating SP -2°F
CP8
Occupied hours
(all hrs. when Fan not off or cycling) = 0.00
Unoccupied hours
= Cooling SP -1°F
(150 F = “off” in unoccupied hours)
Notes:
· For Cooling and Heating control profiles (CP1–8 and HP1–7 ), the timing of the shift between occupied and un-occupied setpoints for each of the four day types (Mon-Fri, Sat, Sun, Hol) includes morning start-up and after-hours operation at the occupied/daytime setpoints. The “setback strategy” determines whether a thermostat setback is used in unoccupied hours and whether HVAC fans stay on, cycle, or shut off.
· CP7 and HP6 control airflow on/off in unoccupied hours and “hand-off” in occupied hours.
· CP8 is a specialized primary airflow profile for systems with fan-powered boxes or similar.
· The economizer profile (EP1) and plant equipment profiles (PP1–4) are fully on during only occupied hours. Because these are modulating profiles, the degree to which they are “on” during occupied and/or unoccupied hours can be less than 100%. The parking garage fan profile (PP4), for example, can maintain 20% airflow in unoccupied hours.
Among the HVAC profiles, CP7, CP8, and HP6 have unique behavior that warrants further explanation:
These three profiles are used in the on-off control of VAV airflow to schedule the min VAV flow rate ON whenever the building is occupied (i.e., during the opening hours set in System Schedules dialog). CP7 and HP6 provide a “hand-off” of the maintenance of minimum airflow for all opening hours between the cooling and heating airflow controllers. The CP8 profile, which is used in system with fan-powered boxes for heating, does not have a corresponding heating airflow control to hand off to, so it forces the cooling airflow control ON for all opening hours via a midband value of 0 ° F. These profiles also force the airflow ON at the min flow (at least) during the closed hours if the system setback strategy is not “HVAC off” and does not include fan cycling.
· When the setback strategy includes fan cycling (either “Temp setback w/ HVAC fan cycling” or Temp setback, HVAC cycling w/OA off”), all three of these profiles provide setback values during the closed hours, such that the airflow is ON during closed hours only if zone the temperature is either below the heating setback or above the cooling set-up value (with midband offsets; see example below).
· When the strategy is either “Temp setback” or “Temp setback w/OA off,” CP7 and HP6 profiles provide a value midway between heating and cooling setpoints during all hours such that one of the two controllers is maintaining at least the minimum VAV airflow at all times. For these strategies, the value of CP8 is zero during all hours such that the minimum VAV airflow is maintained at all times (assuming the zone temperature is never below zero).
· When the setback strategy is “HVAC off” during the closed hours, these profiles have extreme values (150°F threshold for cooling airflow operation and 40°F threshold for heating airflow operation) that prevent the fans from running so long as the spaces are within this very large temperature range.
The contents of 2 HVAC controller profiles relative to setpoints entered in the System Schedules dialog
