Latitude and longitude of building location may be specified to the degree, altitude to the foot, and calculations are made for any range of days of the year, and range of hours desired. Psychrometric calculations are altitude corrected. Uses algorithmic calculations rather than disk database lookup for CLTD's, SHGF's, CLF's and psychrometric calculations, for greater speed and accuracy.
Program code is extensively optimized and fully compiled so at to be exceptionally fast.
Critical portions are done at assembly language level for greatest speed. Computer experience not necessary. Overall design characteristics of the building such as wall, roof and glass specifications and dimensions for each zone. Internal load characteristics must be known. Trials may be run to compare results.