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F-Factor Calculation - ASHRAE 90.1-2007 Table A6.3

Does anyone know what the two different columns for unheated and heated slabs represent in Table A6.3 ? Why are there different F-Factors for the same horizontal insulation distance and the same R-value? The example below that is highlighted is that if I have a slab with 12 inches of R-5 horizontal insulation is the F-Factor 0.72 or 0.61?

image description

F-Factor Calculation - ASHRAE 90.1-2007 Table A6.3

Does anyone know what the two different columns for unheated and heated slabs represent in Table A6.3 ? Why are there different F-Factors for the same horizontal insulation distance and the same R-value? The example below that is highlighted is that if I have a slab with 12 inches of R-5 horizontal insulation is the F-Factor 0.72 or 0.61?

image description

F-Factor Calculation - ASHRAE 90.1-2007 Table A6.3

Does anyone know what the two different columns for unheated and heated slabs represent in Table A6.3 ? Why are there different F-Factors for the same horizontal insulation distance and the same R-value? The example below that is highlighted is that if I have a slab with 12 inches of R-5 horizontal insulation is the F-Factor 0.72 or 0.61?

image description

F-Factor Calculation - ASHRAE 90.1-2007 Table A6.3

Does anyone know what the two different columns for unheated and heated slabs represent in Table A6.3 ? Why are there different F-Factors for the same horizontal insulation distance and the same R-value? The example below that is highlighted is that if I have a slab with 12 inches of R-5 horizontal insulation is the F-Factor 0.72 or 0.61?

image description

F-Factor Calculation - ASHRAE 90.1-2007 Table A6.3

Does anyone know what the two different columns for unheated and heated slabs represent in Table A6.3 ? Why are there different F-Factors for the same horizontal insulation distance and the same R-value? The example below that is highlighted is that if I have a slab with 12 inches of R-5 horizontal insulation is the F-Factor 0.72 or 0.61?

image description