DOE-2 Reference Manual Version 2.1 - DOE2.com

12. CONSTRUCTIONThis instruction is used to specify the construction characteristics andproperties of an exterior wall, exterior floor, roof, interior wall, interiorfloor, ceiling, underground wall, underground floor, or non-glass door. Thisinstruction may also be used to generate Custom Weighting Factors either (1) in alibrary during a LIBRARY-INPUT LOADS run or (2) in the current INPUT LOADS run.A U-name must be specified for this instruction. It identifies thisCONSTRUCTION i~subsequent EXTERIOR-WALL, ROOF, INTERIOR-WALL,UNDERGROUND-WALL, UNDERGROUND-FLOOR, or DOOR instruction.CONSTRUCT! ONLIKELAYERSU-VALUEThis command tells LOADS that the data to follow specify the.construction characteristics and properties of an exterior wall,roof, etc.may be used to copy data from a previously U-named CONSTRUCTIONinstruction.entry for this keyword is either:(1) a code-word from Chap. 25 of the 1977 ASHRAE Handbook ofFundamentals (Ref. 5); use Table 26 (pp. 25.28-25.29) forroofs, Table 27 (pp. 25.30-25.32) for exterior walls, andTable 29 (pp. 25.34-25.35) for interior walls, ceilings,and interior floors,or(2) a U-name of a previously defined (and entered) LAYERSinstruct ion.This identifies the characteristics of the CONSTRUCTION andspecifies heat transfer calculation by the dynamic, or"delayed", technique.When using the former approach, enter code-words ASHW-x forexterior walls, ASHR-x for roofs, and, for Custom WeightingFactor generation, ASHI-x for interior walls, interior floors,or ceilings. In these code-words, x is the the "No." of thewall or roof in Table 26, Table 27, or Table 29 of Chap. 25 ofRef. 5.may be used as an alternative to LAYERS. The heat transfercalculation technique used here assumes that the constructionhas little heat capacitance, and the heat flow is not delayed.Thus a steady-state, or "guick", calculation technique is used.For interior surfaces the U-VALUE should include both filmcoefficients. For exterior surfaces only the inside filmcoefficient should be included; the outside film coefficient iscalculated hourly as a function of surface roughness and windspeed. The following table shows typical U-values for somelow-heat capacity walls.II 1.80 (Revised 5/81)