Relevant specifications for reference of laboratory ventilation and air conditioning design

　　The relevant specifications for laboratory ventilation and air conditioning design reference mainly include:

　　(1) Energy-saving design basis

　　1 "Design Standard for Energy Efficiency of Public Buildings" GB50189-2005

　　(2) Professional technical design basis

　　1 "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" GB50736-2012

　　2 "Technical Code for Biosafety Laboratory Building" GB50346- 2011

　　3 "Code for Design of Scientific Experiment Buildings" JGJ 91-93

　　4 "Chemical Heating Ventilation and Air Conditioning Regulation Design Code" HG/T20698-2009

　　Ventilation equipment commonly used in laboratories

　　Fume hoods are mostly used in laboratories and are the most commonly used local exhaust equipment in laboratories. There are many types of fume hoods. Due to their different structures and different conditions of use, their exhaust effects are also different. The good performance of the fume hood mainly depends on the speed of air movement through the fume hood.

　　Fume hoods are classified according to their usage: they can be divided into integral lower part open type, floor-standing type, two-sided type, three-sided glass type, table-top type, conjoined type, as well as radioactivity experiments and pair synthesis experiments designed according to different experimental use needs. Yes, a special fume hood for perchloric acid experiments.

　　Fume hoods are classified according to the way of air intake

　　1, exhaust type fume hood

　　through the indoor air in the cabinet circulates out of the outdoor is called the full exhaust type, which is a very widely used type.

　　2, supplementary air fume hood

　　When the fume hood is installed in a room with heating or temperature and humidity control requirements, in order to save heating and air conditioning energy consumption, the method of taking the supply air from the outside and circulating it out of the cabinet is called the supplementary air fume hood.

　　3, variable air volume fume hood

　　Ordinary constant air volume system requires manual adjustment of the fixed blade air valve, adjusting the exhaust air volume of the fume hood, and reaching the desired surface wind speed when the valve is adjusted to a certain angle. Variable air volume control is to change the air volume to a given surface wind speed by adjusting the sensor of the valve. Of course, the standard type has low cost and high variable air volume cost, which is suitable for occasions that require high precision.

　　Fume hoods are classified according to the way of exhaust: they are divided into three types: the upper exhaust type, the lower exhaust type and the upper and lower exhaust simultaneously. In order to ensure uniform wind speed in the working area, the lower exhaust type should be adopted for the fume hood in the cold process, and the upper exhaust type should be adopted for the fume hood in the hot process. For the process of unstable heat generation, the upper and lower exhaust outlets can be provided with the cabinet. The change of internal heat generation adjusts the ratio of the upper and lower exhaust air volume, so as to obtain a uniform wind speed.

                                                                                                                                                                 All steel fume hood

　　The main function of the fume hood is the exhaust function. Many chemical experiments produce various harmful gases, odors, moisture, and flammable, explosive, and corrosive substances during operation. In order to protect the safety of users, prevent When pollutants spread to the laboratory, use a fume hood near the source of the pollution.

　　The main goal of laboratory ventilation and air conditioning design

　　1. Ensure the safety of laboratory personnel and working environment

　　Through the design of ventilation and air conditioning, it captures and controls the toxic, corrosive, flammable, explosive, and particulate products produced during the experiment, creating a healthy working environment and favorable working conditions for the staff.

　　2. Control the air pressure in the laboratory

　　The basic principle of laboratory ventilation and air conditioning design is to keep the contaminated area (experimental area, hazardous material storage area, etc.) in the building at negative pressure relative to the clean area (office, corridor, etc.), that is, the air supply volume is less than the exhaust air volume. Ensure that the air in the non-experimental area is relatively clean.

　　3. Provide an appropriate number of air changes

　　The laboratory must not only discharge harmful substances, but also ensure a certain degree of freshness in the air in the room. There must be sufficient fresh air volume to compensate for the exhaust air volume and ensure the number of air changes in the room.