DOE-2 Reference Manual Version 2.1 - DOE2.com

n. Constant-Volume Reheat Fan System (RHFS)OUTSIDEAIR __Ifl~r,T- -[IRUOV[!{YI r~~---PREHEAT[[uIL I' I (OILI (Cor,OM! ZE.'l1I ~ II PHF=i=ii=;r==i==I~ F====lI I :\, IL _ --.J L ___ JCOOUNGCOILHEATnlGCOILr--- -I:HUM1DIFIERI'0 II :III IL ___ ~surPL YFMJRETURN'1RTO OTHER ZONESMIXEDAIRCONTROLSREHEATCOILIHE:AT IIRECOVERY!I CO IL IEXHAUST I HRAI R -- -11====iC I I1-----1IRETURNFANI I IL __ J I _____ -.lJlIIIII EXHAUST I I/~~-~ I- ITEMS SHOWN IN DASHED BOXESARE OPTIONAL COMPONENTSThe Constant-Volume Reheat Fan System is illustrated in the schematicabove. In its most basic configuration, the system provides constant volumeforced-flow heating and cooling to a number of individually controlled zonesfrom an air-handling unit consisting of a filter (not shown), heating andcooling coils, and a draw-through supply fan. Exhaust fan(s) are optional forany or all zones. A reheat coil is installed in the supply air distributionduct serving each individual zone. Space temperature is controlled bythrottling heating fluid flow to these reheat coils. The Stu equivalent ofthe moisture that is added to the air stream, to maintain a minimum humidity,is passed to the PLANT program as a heating load.A number of optional features and control strategies can be specified forthis system. The optional features are discussed in Table IV.2 and thesection entitled, "Explanation of System Options" (immediately following TableIV.2). The possible control strategies for this system are discussed in Sec.S.5 of this chapter. It is highly recommended that the user read that portionof Sec. B.5 that is applicable to this system.Table IV.16 shows the command and keywords that must be entered forsimulation of this system, as well as those that are applicable but optional(i.e., pro.gram uses default value if entry is omitted.)I V.67 (Revised 5/81)