DOE-2 Reference Manual Version 2.1 - DOE2.com

3. Explanation of System Options1)2)3)4)5)Outside Air Option: A fixed quantity of outside air, or one of twodifferent types of economizer cycles, can be specified (see keywordOA-CONTROL and MIN-OUTSIDE-AIR in SYSTEM-AIR subcommand).Return Air Option: Return air may be pulled back to the air-handlingunit by the supply fan, or a separate return air fan may be specifiedfor this purpose (see keywords RETURN-CFM, RETURN-DELTA-T, RETURN-KW,RETURN-STATIC, and RETURN-EFF in SYSTEM-FANS subcommand). The airmay be returned directly from the conditioned space or be drawnthrough a return air plenum (see keyword RETURN-AIR-PATH in theSYSTEM command).Exhaust Fan Option: Direct exhaust, independent of the return airsystem, may be specified for one or more zones (see keywordsEXHAUST-CFM, EXHAUST-KW, EXHAUST-STATIC, and EXHAUST-EFF in theZONE-AIR subcommand).Fan Control Option: One of seven different methods of reducingsystem fan capaclty, in accordance with system flow requirements,can be specified: fan discharge damper, fan inlet vanes, variablefan speed, and cycling for variable volume systems; two-speed forPTAC system; and standard constant-volume. In addition, the usermay input his own fan curve (see keyword FAN-CONTROL in the. SYSTEM-FANS subcommand).Supply Air Temperature Control Option: The temperature of supplyalr, dlscharg1ng from the primary alr supply unit of single-ductsystems, can be maintained constant, can be reset in accordance withoutside air temperature, can be scheduled in time, or can be basedon the requirements of the warmest zone (see keyword COOL-CONTROL inthe SYSTEM-CONTROL subcommand). Note: RESET outside airtemperature control is most commonly used with the two-pipeinduction system.6) Coil Temperature Control 0 tion: The temperature of the aireav1ng the centra or main eat1ng coil of single-duct airsystems is constant and is controlled by the value specified (ordefaulted) for HEAT-SET-T (see SYSTEM-CONTROL subcommand).7) Reheat Coil Option: Reheat (zone) coil operation for single-ductair systems 1S controlled by the user input for the keywordREHEAT-DELTA-T (see SYSTEM-TERMINAL subcommand) and the hourlyvalues referenced by HEAT-TEMP-SCH (see ZONE-CONTROL subcommand).8) Hot Deck Temperature Control Option: Hot deck temperature fordual-duct air systems can be maintained constant, can be reset inaccordance with outside air temperature, can be scheduled in time,or can be based on the requirements of the coldest zone served bythe system (see keywords HEAT-CONTROL, HEAT-SET-T, HEAT-SET-SCH, andHEAT-RESET-SCH in the SYSTEM-CONTROL subcommand).I V.15 (Revised 5/81)