 
															
					To be able to move large volumes of air through a ventilation system or localized extraction system, in the vast majority of cases it is necessary to apply a lot of energy and this regularly comes from the fans, although in some cases it can also be applied as natural form.				
				 
								 
															 
															 
															 
															 
															 
															 
															 
															 
															 
								 
															 
															 
															