DOE-2 Reference Manual Version 2.1 - DOE2.com

If MIN--AIR-SCH is used, the value of the outside air flowrate, to be used in the design calculations, should bespecified either in this keyword or in the zone levelkeywords.If no outside air has been specified, no moveable dampers aresimulated, even if OA-CONTROL equals TEMP or ENTHALPY.(Note: The program will not allow MIN-OUTSIDE-AIR to be lessthan the sum of EXHAUST-CFMs for all zones divided by the sumof all supply cfm's for all zones. That is, the exhaust fanoperation will override MIN-OUTS IDE-AIR, if MIN-OUTS IDE-AIRis set too low).MIN--A IR-SCHOA-CONTROLis the U-name used to identify the schedule for the ratio ofminimum outside air flow to supply air flow. Values in theMIN--AIR-SCH vary as a function of time from 0 which indicatesno outside air flow Tand 100 percent return air) to 1 whichindicates 100 per cent outside air flow (with no return airflow). A value of 0.5 indicates a minimum of 50 per centoutside air flow. If EXHAUST-CFM in any zone (within thissystem) is not equal to zero in a givenhour, the schedulereferenced by MIN-AIR-SCH should not be zero in that samehour. The program does not use MIN-AIR-SCH in des i gn ing thesystem; therefore, if the user wants the program to size theSYSTEM, he should also specify a value for MIN-OUTS IDE-AIRthat is representative of the outside air flow rate. A valueof zero for an hour overrides any economizer operation andforces a no outside air system. Any value greater than zeroallows economizer action as specified in OA-CONTROL.Input for th is keyword is the code-word for the type ofoutside air control strategy selected. See Table IV.34 forthe code-words and a brief description of the controlstrategy each represents. Input for this keyword must beFIXED if the user does not want an economizer. It willdefault to TEMP, WhlCh will simulate a temperature-controlledecon omi z er •If no outside air has been specified, no moveable dampers aresimulated, even if OA-CONTROL equals TEMP or ENTHALPY.RECOVERY-EFFis applicable only to those systems provided with heatrecovery coils (or other devices) for the exchange of heatbetween the air exhausted from the building (by the returnair fan) and the fresh air supplied to the building. Theinput is the ratio (decimal fraction) of the energy actuallyexchanged to the total sensible energy that would be exchangedif the exhaust air were cooled to outside air temperature.The program uses this ratio (plus outside air and exhaust airtemperatures and exhaust air flow rate) to calculate theenergy that can be added to the outside air make-up. If therecoverable energy is greater than that needed by the supplyIV.215 (Revised 5/81)