https://www.dekut.com/World_Business/industrial-commercial-ventilation-vital-factors-/ Mechanical ventilation helps larger buildings with sealed windows and heavy insulation for being highly energy efficient. Irrespective of whether it is a small, older or low occupancy office building, all of these kinds can be adequately ventilated with the help of natural sources. This objective is ordinarily accomplished via the air leakages through opened windows and doors. Similarly, this can also be attained through cracks in the walls and windows and other openings. Tue, 04 Feb 2014 08:40:35 UTC en