There are two types of high-precision constant temperature and humidity air conditioning and ventilation systems for clean laboratories, one is centralized and the other is decentralized. The former is suitable for clustered, multi-room, multi-requirement, and multi-functional clean laboratories. The advantages are easy management, away from noise, and reduced costs. The latter is suitable for smaller clean laboratories or laboratories with individual characteristics. The advantages are fine control and strong pertinence.
1. The selection principle of high-precision constant temperature and humidity air conditioning and ventilation systems must meet the purification requirements.
    In actual selection, people often choose the type of high-precision constant temperature and humidity air conditioners based on funds and energy consumption, ignoring that the fundamental purpose of selection is to meet needs and meet purification standards.
    Before selecting the model, we must understand the purpose and experimental content of the clean laboratory, the experimental instruments and equipment, the specific requirements of the experimental objects for air parameters and environment, and then put forward targeted purification standards. The contents that should be considered include: the area of ​​the laboratory, the floor height, the total height of the laboratory and the height of the clean laboratory enclosure; the desired temperature, relative humidity, wind speed, static pressure, static pressure difference, etc.; the clean level, noise standard, sterility requirements, etc. required in the laboratory. After comprehensively considering these factors, an appropriate funding requirement is proposed to determine the specific form and type of high-precision constant temperature and humidity air conditioning ventilation system.
2. The selection of high-precision constant temperature and humidity air conditioning ventilation system should be done according to one's ability and as appropriate.
    The reason why the clean laboratory is clean is that first of all, a special process is used to block the free exchange of air and the use space, and then the air is processed and transported to the use space by artificial means. Of course, both fresh air and turbid air must be transported here. The so-called turbid air is to transport the air in the use space to the outside world after treatment to make it clean air and then transport it back to the use space.
    The principle can be simplified by the following flowchart: air flow → primary air treatment → air conditioning → medium-efficiency air treatment → fan air supply → purification duct → high-efficiency air supply outlet → clean room → dust removal → return air channel → fresh air, primary air treatment.
    The high-precision constant temperature and humidity air conditioning ventilation system used in clean laboratories is mainly composed of air treatment equipment, coarse and medium-efficiency filters, air delivery facilities and local purification equipment, which are of different types and have different functions.