DOE-2 Reference Manual Version 2.1 - DOE2.com

19. UNDERGROUND-WALL (or UNDERGROUND-FLOOR)This instruction is used to specify the size and construction of an undergroundwall, underground floor, or a floor on the ground (slab-on-grade). Itis essentially an INTERIOR-WALL without the NEXT-TO keyword as far as dataentry is concerned. Each UNDERGROUND-WALL or UNDERGROUND-FLOOR instructionapplies to the SPACE instruction preceding it and describes one of the undergroundwalls or underground floors of that SPACE.Specifying the U-value and the area of a floor in contact with the soilcalls for some engineering judgement. Using the actual U-value of the floorconstruction and the total area of the floor will drastically overestimate theheat loss through the floor, because the floor will tend to raise the temperatureof the surrounding soil. Depending upon whether or not Custom WeightingFactors are being used, the user should specify either an effective (lower)U-value, or an effective (lower) area.U-namemay be specified.UNDERGROUND-WALL (or UNDERGROUND-FLOOR) This command word tells LOADS thatthe data to follow specify an underground wall or undergroundfloor.LIKEAREAHEIGHTis analogous to LIKE for INTERIOR-WALL.the definition of AREA for UNDERGROUND-WALL orUNDERGROUND-FLOOR depends upon whether or not the user isusing Custom Weighting Factors.If Custom Weighting Factors are being used, AREA is definedas the total surface area of the UNDERGROUND-WALL orUNDERGROUND FLOOR. This total area will be used in thecalculation of Custom Weighting Factors; however, a valuemust be specified for U-EFFECTIVE.If Custom Weighting Factors are not being used, AREA isnormally defined as the perimeter area (i.e., the linearperimeter expressed as ft2) of the UNDERGROUND-WALL orUNDERGROUND-FLOOR. This definition may be interpreted asthe effective (lower) heat transfer area, but it may varyaccording to engineering judgement. This effective areawill be used with the numerical value specified for thekeyword U-VALUE in the CONSTRUCTION instruction tocalculate heat transfer through the UNDERGROUND-WALL orUNDERGROUND-FLOOR.is the dimension of the underground wall or undergroundfloor parallel to the Y axis in the surface coordinatesystem (see Sec. A.5 of this chapter). It is suggestedthat this keyword be used only if Custom Weighting Factorsare being used. If Custom Weighting Factors are not beingused, it is suggested that the user specify instead AREAaccording to its second definition.III .118 (Revised 5/81)