DOE-2 Reference Manual Version 2.1 - DOE2.com

Code-WordDIRECTDUCTPLENUM-ZONESTABLEIV.43RETURN -A I R- PATHThis code-word is used when the return air flows back tothe air handler or relief point (central exhaust) viahallways and stairwells. All heat from lights specified inLOADS should go 100 per cent into the ZONE air or it islost. Only return fan heat is added to the air stream.Use of this code-word causes the heat from lights (1 -LIGHT-TO-SPACE in the LOADS program), in addition to returnfan heat, to be added to the air stream. This code-word isused in two ma in cases: (1) when return air duct work 'actually exists in the building and (2) when the return airpasses through a plenum, but little heat gain or loss isexperienced in this plenum. The second case allows greatsimplification of input. The user specifies theconditioned areas and ignores the specification of theplenum areas. The heat of lights exhausted to the plenum(specified in the LOADS program) is still added to thereturn air. When using this option and also specifying anon-return air plenum, the plenum should be specified asZONE-TYPE = UNCONDITIONED.This code-word is used when the user wishes to simulateheat exchange between the return air stream and the plenumwall mass. Heat from lights is added to the air stream,then it is allowed to interact with the ZONEs (attached tothis SYSTEM) that are specified as ZONE-TYPE = PLENUM andare listed in PLENUM-NAMES. After heat exchange iscalculated with the plenum ZONEs, the return fan heat (ifany) is added. Use of this code-word requires at least oneZONE (but not more than three) specified as ZONE-TYPE =PLENUM in the PLENUM-NAMES list.IV.263 (Revised 5/81)