Roof reflectivity is entered by going to construction types, selecting roofs, copy a similar roof (remember mass is important), and then alter that roof by going to the advanced button and changing the absorbtivity (the first field).
To model a reflective roof, Use absorbtivity, since reflectance= 1 - absorbtivity
Very Good Point Bobba. The late Clair Jacobson used to give some very funny advice on this. If I recall correctly, he talked about bird scat and a number of other real-world scenarios.
bobfasenbender@energy-models.com
Remember they get dirty, so don't model them as new and prestine...and I have not seen a cleaned roof that is not dirty again within 3-5 years.
Be Sustainable -- Never let today use up tomorrow!.
Very Good Point Bobba. The late Clair Jacobson used to give some very funny advice on this. If I recall correctly, he talked about bird scat and a number of other real-world scenarios.