It shall be ducted to a roof or wall cap using 4” round ductwork." Bottom line: a 4-inch exhaust duct diameter is perfectly permissible and will work fine as long as the CFM rate of the fan OR the length of duct run (including effects of elbows or bends) does not exceed what ...
In the present work, the entire system of a wind turbine is considered. The literature about wind turbines for low wind speed areas is very limited. Some studies work on the shape optimization of low wind speed wind turbine blades, but the object models are always the micro wind turbine [...