The key points of laboratory ventilation system design mainly include the following aspects:

1. Design parameters

Laboratory area and height: Reasonably configure according to the laboratory area and height to ensure air circulation and ventilation efficiency.

Types and concentrations of pollutants: Determine reasonable emission control measures based on the types and concentrations of pollutants that may be generated during the experimental process.

Laboratory operation requirements: Understand the operational requirements during the experimental process, such as the handling of experimental materials, sample preparation, etc., in order to arrange the layout of the ventilation system reasonably.

Environmental conditions: Consider the environmental conditions of the laboratory location, such as climate, air quality, etc., to select suitable ventilation equipment and materials.

2. Equipment selection

Fan: a power source used to generate air flow, which can be selected from various types such as centrifugal and axial flow.

Duct: A piping system used to transport air, which requires consideration of factors such as pipe material, size, and installation location.

Ventilation vent: A device used to expel air from the outdoors, which can be a natural ventilation vent or a mechanical ventilation vent.

Air purification equipment: used to filter and purify pollutants in the air, such as activated carbon filters, high-efficiency filters, etc.

Ventilation cabinet: Used for absorbing and discharging pollutants generated during the experimental process, suitable materials and configurations need to be selected.

3. Layout planning

Ensure smooth air circulation inside the laboratory to avoid the formation of dead corners or vortex zones.

The position of ventilation openings should be as close as possible to the source of pollution to reduce the spread and impact range of pollutants.

For laboratories containing highly toxic pollutants such as volatile organic compounds, an independent exhaust system should be installed to avoid affecting other areas.

Consider the temperature and humidity control requirements in the laboratory, and choose ventilation equipment and materials reasonably to avoid the impact of temperature and humidity fluctuations on experimental results.

Set up corresponding ventilation systems according to the requirements of different experimental operations, such as local exhaust hoods, mobile exhaust hoods, etc.

On the premise of meeting the requirements of experimental operation, try to minimize the noise interference of the ventilation system and the impact on the experimental personnel.

Consider the possibility of future laboratory expansion or renovation, and reserve sufficient space for ventilation system expansion.

4. System control

In small-scale laboratories or teaching laboratories, the exhaust system set up one-on-one with local exhaust equipment can adopt a constant air volume control method.

The exhaust system serving multiple local exhaust devices should adopt a variable air volume system to save operational energy consumption. The air volume at each end is controlled by a constant air volume valve or a variable air volume valve to avoid interference with each other.

The variable air volume valve on the exhaust cabinet should have emergency function. When the emergency button on the exhaust cabinet is activated, the exhaust volume of the cabinet should be able to reach the maximum value.

The fixed air volume control method can be used for the one-to-one setting of the supplementary air system with the fixed air volume exhaust system; The supplementary air system corresponding to the variable air volume exhaust system should control the variable air volume based on the target value of the air supply and exhaust volume difference or the indoor and outdoor pressure difference.

5. Safety measures

The dust removal capacity of the fume hood should meet certain standards and regulations. The airflow direction should flow towards the laboratory. The laboratory should maintain negative pressure at all times.

The traditional laboratory control method is constant air volume control. The new control mode is adaptive control mode, where the air volume is kept at the minimum safe limit and the working state of the fume hood can be adjusted according to the user's status. This system has the advantages of sensitive response, accurate control, ensuring personnel safety, and minimizing energy consumption and maintenance costs.

6. Environmental protection measures

The exhaust of experimental animal facilities should not affect the air quality of the surrounding environment. Considering that the exhaust of animal experiments has a strong odor, an activated carbon deodorization device is installed. To avoid odor leakage through the exhaust duct, the activated carbon filter absorber should be installed in the negative pressure section.

The gases emitted from the chemical laboratory need to be directly discharged outdoors and cannot be recycled. The exhaust of the chemical laboratory is treated with activated carbon filter absorbers according to the process requirements, and high-altitude emissions are adopted (exhaust distance from the roof where the fan is located is more than 3 meters).

7. Compliance with standards

Strictly adhere to relevant specifications and standards during the design and construction process to ensure the safety and reliability of the ventilation system.

8. Debugging and testing

Before putting into use, conduct comprehensive debugging and testing of the ventilation system to ensure its normal operation and compliance with relevant standards for pollutant emissions.