There is always a need to provide fresh air or return air from modern structures that include engineering and fundamental ventilation systems. A fresh air louver is used on the fresh air intake to ensure that only air enters the new air supply duct and to prevent the entry of rain, snow, and other materials. The buildings outside wall may occasionally serve as the terminus of the ventilation duct, or the structure may have an air conditioner chamber where the building’s air conditioners and other air conditioning equipment are located. Ventilation louvers ensure that the building’s exterior doesn’t have aesthetic issues and that the equipment and building receive the fresh air they need. Bird netting is typically put behind the louvers to keep birds out.