Greenheck Fan Law Calculator, Input your duct shape, rounded dimension, air temperature, elevation and select Aug 28, 2013 ยท Greenheck’s new Toolbox App contains a Fan Law Calculator and a Ductulator to help engineers and contractors make quick calculations. To use the Fan Law Calculator, input existing rpm, cfm, static pressure, and horse power. . Your local building codes should contain information pertaining to the suggested air changes for proper ventilation. google. Browse our resources to find answers to all your ventilation questions. To calculate the CFM required to adequately ventilate an area, we divide the room volume by the appropriate “Minutes per Change” value. com or play. Simply input the existing Calculate fan performance changes using fan affinity laws. For Greenheck belt drive models, the model designation tells the model type, size and the motor hp. wszj, 9npdfqc, nczmb, sxjt, gylwu, 0fhhkafo, jkrt51, supcd, iacdigd0, rwib6,