DOE-2 Reference Manual Version 2.1 - DOE2.com

NEXT-TOMULTIPLIERSOLAR-FRACTIONof the "wall" between the spaces; and Time is the mean timefor the heat transfer to occur. Any larger U-value willviolate the second law of thermodynamics, that is, takingmore heat energy from the air in the space than isavailable. For Time ~ 5 minutes and for usual geometries,U ~ 2.7. This is a maximum U-value for nonexistentpartitions or open doors.More complex boundaries such as walls with large areas ofglass and with large openings require the user to estimatethe effective U-value. However, the effective U-valuecannot exceed the value for free air as discussed above.For runs in which Custom Weighting Factors are to be created(LIBRARY-INPUT LOADS runs), the CONSTRUCTION defined by thiskeyword may be a delayed construction. In such a case, thedelayed construction may be left in the input deck for theregular INPUT LOADS run; LDL will simply substitute thecalculated U-value for the delayed construction.identifies the space that shares this interior wall,ceiling, or interior floor as a boundary with the spaceunder consideration.is used to specify the total number ofwall panels. This reduces data input.area of the INTERIOR-WALL instruction.identical interiorIt multiplies theWarning: The user should use care when specifyingMULTIPLIER in an INTERIOR-WALL instruction. All multipliedINTERIOR-WALLs will be NEXT-TO the same SPACE, whether thisis physically true or not.The following keywords may be used if the user elects to useCustom Weighting Factors:accepts as input the fraction of the solar radiation, direct,diffuse, and reflected, coming through the glazings in thespace that is absorbed by this interior wall, interior floor,or ceiling. Note that this is the fraction of radiationabsorbed, not the fraction that actually enters the space.For example, in a given space, the floor may receive .55 ofthe radiation, each of the walls .1, and the ceiling .05.A CAUTION message will be issued if the sum of theSOLAR-FRACTIONs for a given space is not within 10 per centof 1.0, and the program will adjust the SOLAR-FRACTIONs sothat their sum is 1.0. Each SOLAR-FRACTION will then beautomatically multiplied by a factor that accounts for theamount of incoming solar radiation that is reflected backout of the space through the glazing.If all SOLAR-FRACTIONs for a space are allowed to default,the program will assume that 60 per cent of the incomingII 1.114 (Revi sed 5/81)