• • • • • • • •   ASHRAE The global leader in the arts and sciences of heating, ventilation, air conditioning and refrigeration. DOE-2 A widely used and accepted building energy analysis program that can predict the energy use and cost for all types  of buildings. NOAA Weather Data The world's largest active archive of weather data. Online Engineering Calculators Make Psychometric calculations. Pressure Drop in Piping Calculator Determine your piping pressure drop. Typical Meteorological Year Weather Data Contains data files for the typical meteorological year (TMY) data sets. Underwriters Laboratories Inc. The leader in U.S. product safety and certification. UL is an independent, not-for-profit product safety testing and certification organization. The Engineering Tool Box - HVAC Systems