DOE-2 Reference Manual Version 2.1 - DOE2.com

Hot Deck Air Flow and Temperature for the COLDEST ZONE - At calculated ZONEtemperatures above the heatlng THROTTLING-RANGE, the air flow rate in the hotduct is zero. As the calculated ZONE temperature drops from the top to approximatelythe midpoint of the heating THROTTLING-RANGE, the air flow rate in thehot duct increases linearly from zero to the MIN-CFM-RATIO (this is accompaniedby an opposite action in the cold air duct). Also, as the calculated ZONE temperaturedrops, the hot deck temperature is raised linearly such that at thebottom of the heating THROTTLING-RANGE the hot deck is completely turned on.For calculated ZONE temperatures below the midpoint of the heatingTHROTTLING-RANGE, the air flow rate in the hot duct remains at theMIN-CFM-RATIO and the hot deck continues to rise toward its maximumtemperature.For those ZONEs other than the COLDEST ZONE, the damper actions (air flowrates) are identical to those of the COLDEST ZONE; however, their heatingsupply air temperature is determined by the COLDEST ZONE.Procedure:(1) Specify SYSTEM-TYPE = MZS, DDS, or PMZS in the SYSTEM command.(2) Specify MIN-CFM-RATIO (in either the ZONE command or in the SYSTEM­TERMINAL subcommand) equal to some value less than 1.0 (settingMIN-CFM-RATIO equal to 1.0 will not simulate this control strategy).This, along with THERMOSTAT-TYPE = PROPORTIONAL, assures a variablevolume mixed air flow entering this ZONE(s) for cooling and aconstant volume mixed air flow entering the ZONE(s) for heating.(3) Specify COOL-CONTROL in the SYSTEM-CONTROL subcommand equal toWARMEST. This determines the method for setting the hourlytemperature of the cooling supply air that will be sent to all ZONEsin the SYSTEM. If the user does not specify a value forCOOL-CONTROL, it will default to CONSTANT and the intended controlstrategy will not be simulated.(4) Specify HEAT-CONTROL in the SYSTEM-CONTROL subcommand equal toCOLDEST. This determines the method for setting the hourly temperatureof the heating supply air that will be sent to all ZONEs in theSYSTEM. If the user does not specify a value for HEAT-CONTROL, itwill default to CONSTANT and the intended control strategy will notbe simulated.(5) Specify COOL-TEMP-SCH in the ZONE-CONTROL subcommand (and an associatedSCHEDULE) with hourly values of ZONE thermostat set pointtemperature for cooling. These temperatures will be used to modulatethe cold deck temperature and the air flow in the cold air duct tothe ZONE. If the user doeS-Oot specify a COOL-TEMP-SCH for one ZONEin a multizone SYSTEM, it will be cooled, but without cooling (airvolume) control.(6) Specify HEAT-TEMP-SCH in the ZONE-CONTROL subcommand (and an associatedSCHEDLLE) with hourly values of ZONE thermostat set pointtemperature for heating. These temperatures will be used to modulatethe hot deck temperature and the air flow in both the cold and hotIV.124 (Revised 5/81)