Hi Could any one clarify this :
"By default, exterior roof surfaces, other than those with ventilated attics, must be modeled assuming a surface reflectance value of 0.30. When a proposed design calls for a reflective roof surface, however, the model may assume a long-term average reflectance of 0.45, which credits the lower heat absorption of the reflective surface and makes a conservative allowance for degradation of the reflectivity over its lifetime. In order to qualify for this credit, the reflectance of the proposed design roof must exceed 0.70, and its emittance must exceed 0.75. "
So does this mean , if my proposed case roof has a higher roof reflectivity than 0.70 and higher emmitance than 0.75 ,means my base case roof reflectivity should be 0.45 , if it is the case then my there will be reduction in my savings of the proposed case with the base case , then how will this becomes a credit
Thanks and Regards