【 Weak current college 】 building ventilation and smoke-the first section of the basics of building ventilation

This study includes ventilation system concept, function and form classification, requires good ventilation of the concept and scope of selection for ventilation. First, the ventilation system concept and role of building ventilation is building room polluted air purification treatment directly or through the rear-outdoor, fresh air supplements come in, to keep the indoor air environment in accordance with hygienic standards process. Visible, ventilation is to improve the air condition one of the methods, which include air from the Chamber preclude the foul and indoor complement fresh air, former known as exhaust, the latter is called air.　　Realization of exhaust and air supply used by a range of equipment, equipment for collectively ventilation system.　　Building ventilation are often applied to production and life, former known as industrial ventilation. Second, the ventilation system in the forms and classification of ventilation systems can be divided into natural ventilation and mechanical ventilation.　　Natural ventilation is the use of hot and cold air inside and outside the room density differences and room surfaces, the Lee side of the wind pressure and low for air-exchange; mechanical ventilation is the use of ventilation equipment to the building (room) is being fed into or from a certain amount of air, air exchange and processing. According to the scope of the different ventilation, mechanical ventilation can be divided into comprehensive ventilation, ventilation and three hybrid ventilation.　　What is the main ventilation mode depends on the generation and spread of harmful substances in the range of size, hazardous substances area is used instead of the full ventilation may be partial and hybrid ventilation. In the calculation of natural ventilation, usually the exterior wall and beyond the sides of the pressure difference is called the residual pressure, such as a window holes top pressure is positive, the exhaustion Fenestrae; top pressure is negative, the Fenestrae inlet; when the window holes located on the top pressure to zero pressure surface, in the upper portion of the window hole, the lower part of the exhaust air.　　In the buildings, the residual voltage zero plane called and surface and, therefore, is located in the following form and surface holes exhaust window, located at and above the surface of the window hole is a form of air. Hot press of natural ventilation, use of indoor and outdoor air temperature of the forming of density, pressure difference of indoor and outdoor air exchange. When the buildings affected by wind pressure and heat pressing together, in the building perimeter of the window hole on the role of differential pressure is equal to its inside and outside the wind pressure and heat. Take full advantage of the wind pressure, hot pressing of natural ventilation is modern green building one of the important content is to improve indoor air quality, to create a comfortable environment preferred.