The ventilation system is a kind of building environment control device to control the spread of air pollutants and hazards using air exchange and dilution or ventilation exclusion and to realize indoor and outdoor air environment quality assurance. There are many types of ventilation systems.
Ventilation system classification
According to the ventilation power classification: natural ventilation, mechanical ventilation;
According to the scope of ventilation services: comprehensive ventilation, local ventilation;
According to the direction of airflow classification: send (into), exhaust (smoke);
According to the purpose of ventilation classification: general ventilation, hot air heating, detoxification and dust removal, accident ventilation, protective ventilation, building smoke, and so on;
Classified according to the location of power: power centralized and power distributed.
Ventilation system function
Using the fresh air from outside to reduce indoor air pollution due to the living and living process, to maintain the cleanliness of indoor air to reach the level of a certain minimum standard.
It increases heat dissipation in the body and prevents the discomfort caused by the moisture of the skin, and this kind of ventilation can be called thermal comfort ventilation.
When the indoor air temperature is higher than the outdoor air temperature, the building components cool down, this type of ventilation is called building cooling ventilation.
Composition of Ventilation System
A ventilation system generally consists of ventilation equipment, a ventilation pipe, a muffler, a fan, control system.
1. Ventilation equipment
Commonly used ventilation equipment in the laboratory are detoxification cabinets, atomic absorption hoods, universal exhaust hoods, desktop fume hoods, and so on. The detoxification cabinet is safe to deal with harmful, toxic gases or vapors of the ventilation equipment, the role is used to capture, seal, and transfer pollutants and harmful gases, to prevent them from escaping into the laboratory, so that through inhalation pollutants in the work area, so that the operator inhalation exposure to the pollutants to minimize. The airflow in the detoxification cabinet through the exhaust fan will be sucked into the laboratory air into the detoxification cabinet, and the detoxification cabinet contaminated gas 桸 release through the ventilation system to the outdoors after the exhaust can be achieved after the diffusion of low concentrations.
2. Ventilation Duct
For general construction, if the indoor discharge of gas is not corrosive, ventilation ducts can be galvanized steel, for the production of corrosive gases in the laboratory, the duct should be corrosion-resistant materials of PVC duct or glass-fiber reinforced plastic duct. In general laboratory ventilation projects, most of the indoor PVC ducts, and outdoor glass fiber-reinforced plastic ducts.
3. Fan
Fans are mainly axial fans, inclined flow fans, and centrifugal fans. Axial fan, inclined flow fan is suitable for small wind pressure, short pipeline ventilation system, such as a direct discharge to the window or wall ventilation system, referred to as direct discharge; glass from the steel centrifugal fan is suitable for the long pipeline ventilation system, such as through the air duct well or the external wall takes over to the roof, referred to as the roof discharge. Fan material: generally divided into glass steel, PP, PVC, and so on. The model of the fan is selected according to the wind volume and wind pressure.
4. Ventilation control system
Ventilation control systems can be controlled in different ways according to different situations, such as single ventilation equipment fixed air volume ventilation control system, multiple ventilation equipment frequency control system, and multiple ventilation equipment frequency + variable air volume ventilation control system.