DOE-2 Reference Manual Version 2.1 - DOE2.com

COOLING-SCHEDULE, HEATING-SCHEDULE, and FAN-SCHEDULEThe keywords COOLING-SCHEDULE and HEATING-SCHEDULE are used to referenceSCHEDULE instructions that activate and deactivate the cooling and heatingcapab il it i es of the PLANT. These SCHEDULEs do not turn the PLANT "ON" and"OFF"; rather, they specify the availability of heating and cooling for thisSYSTEM {some SYSTEMs served by a PLANT may be "ON" and some may be "OFF"-Y-:--ASYSTEM may be calling for heating, however, that heating will not be availableunless the HEATING-SCHEDULE is referencing a SCHEDULE thatlS specified as "ON"during that hour (possessing a positive hourly value). The same is true withrespect to the COOLING-SCHEDULE. Similarly, FAN-SCHEDULE references a SCHEDULEinstruction that specifies the availability of the system's fans (supply,return, and exhaust). Note: There is one exception to the precedingdiscussion. If the user specifies any value for NIGHT-CYCLE-CTRL other thanSTAY-OFF, the FAN-SCHEDULE may be overidden to provide heating should the ZONEtemperature fall below the heating THROTTLING-RANGE (see NIGHT-CYCLE-CTRL,Sec. C.8 of this chapter).Zone Thermostats and THROTTLING-RANGEs:·In DOE-2 the ZONE thermostats have two control bands, or THROTTLING-RANGEswith associated set points, and one dead band. Some system control strategiesinvolve only one ZONE thermostat set point, which is used to control eitherheating or cooling of the ZONE. Other strategies involve two ZONE thermostatset points, one for cooling and one for heating. The desired set points arespecified, respectively, with the keywords COOL-TEMP-SCH and HEAT-TEMP-SCH(plus their associated SCHEDULEs). Each set point has its own THROTTLING-RANGE.Only one specification for THROTTLING-RANGE can be made for a ZONE and thatrange is used for both cooling and heating.In general, the upper control band, or cooling THROTTLING-RANGE, governsthe main cooling coil (for central systems), the zone cooling coil (for zonalsystems), and the air volume for variable volume systems (MIN-CFM-RATIO < 1).At the top of the cooling THROTTLING-RANGE there is full cooling and full airvolume. At the bottom of the cooling THROTTLING-RANGE there is minimumcooling and minimum air volume.The lower control band, or heating THROTTLING-RANGE, governs the mainheating coil (for central systems), the zone heating coil (for zonal systems),the reheat coil, the thermostatically controlled baseboards, and the airvolume (for variable volume systems with THERMOSTAT-TYPE = REVERSE-ACTION).At the bottom of the heating THROTTLING-RANGE there is full heating and in thecase of THERMOSTAT-TYPE = REVERSE-ACTION, full air flow. At the top of theheating THROTTLING-RANGE the heating is off and the air flow is at a minimum.If the cooling and heating set points are separated by more than oneTHROTTLING-RANGE, a dead band will result between the two THROTTLING-RANGEs.The response of the system, ,when the calculated ZONE temperature is within thedead band, will be constant and will correspond to the system response at thebottom of the cooling THROTTLING-RANGE. If the user specifies overlappingTHROTTLING-RANGEs, the program will assume that the user has made an error andit will move the set points apart until they are separated by oneI V.106 (Rev i sed 5/81)