testing, precision machining, three-coordinate testing, scientific research institutions and other places. Therefore, the requirements for constant temperature and humidity laboratory design are becoming stricter and more standardized. The Shanghai laboratory construction expert will explain in detail the air conditioning and fresh air system designed by the constant temperature and humidity laboratory.

I. Design requirements for constant temperature and humidity laboratories in different industries

1. Precision manufacturing industry: commonly used conventional constant temperature and humidity laboratories, the temperature is set at 18-30 ℃, and the humidity is set at 45%-70%.

2. Pharmaceutical research industry: commonly used low-temperature, constant-temperature and constant-humidity laboratories, the temperature is set at 12-18°C, and the humidity is set at 45%-70%.

3. Biological culture industry: commonly used ultra-low temperature constant temperature and humidity laboratory, the temperature is set at 5-12 ℃.

4. Electronic product aging test: commonly used high temperature and high humidity aging room, the temperature is set at 30-80℃, and the humidity is set at 40%-95%.

II. Matters needing attention in the design of constant temperature and humidity laboratory

Laboratory air conditioners are the heart of temperature and humidity control, requiring high precision and low failure rate. Therefore, the air conditioner must be required to adjust the cooling capacity. There are two ways on the market: one is frequency conversion adjustment; the other is chilled water adjustment. The demand for constant temperature and humidity environment is increasing, and the application field is also wider and wider.

The environmental parameters of the constant temperature and humidity laboratory should be determined according to the requirements of the product, the object of the experiment, and the requirements of the experimental equipment. Different accuracy and reliability will cause great complexity in the constant temperature and humidity system, and will also affect the initial investment and operating costs of the system to a large extent. If the design of a constant temperature and humidity laboratory blindly increases the accuracy requirements, it will usually increase the initial investment and operating costs. On the contrary, if the accuracy requirements are too low, it will cause the failure of production and experimental activities. Therefore, before proceeding with the laboratory design, you need to know what are the precautions.

1. It is necessary to conduct safety education for all laboratory personnel in the laboratory and establish a solid safety awareness in their hearts. In accordance with the equipment, environment and experimental characteristics of the constant temperature and humidity laboratory, the management measures for fire prevention, theft prevention and accident prevention shall be formulated and strictly implemented.

2. When designing a constant temperature and humidity laboratory, the instrument room, critical areas, and flammable and explosive materials should be protected to ensure that safety measures are foolproof. If necessary, it is best to set up a safety early warning system.

3. The water and electricity equipment and pipeline facilities in the laboratory should be assembled in accordance with the requirements, and should not be randomly connected, modified or changed at will. All kinds of equipment in use must be ensured in a safe state. 

4. It must be equipped with fire-fighting equipment that meets the requirements and placed in an obvious and easy-to-reach place. There must be a dedicated person responsible for management and regular inspections to ensure that it is always useful.

Finally, the design of the constant temperature and humidity laboratory needs to strictly abide by the relevant regulations of the environmental protection department of our country, and it is not allowed to discharge waste gas and waste gas cultures that exceed the regulations at will.

III, the air-conditioning setting designed by the constant temperature and humidity laboratory

Temperature and humidity control is a key point in the design of a constant temperature and humidity laboratory. The accuracy of the air conditioner is relatively high, and the air conditioner must be able to control and adjust the cooling capacity. This is mainly achieved through two channels:

1. Frequency conversion adjustment: Its essence is to change the power of the compressor by changing the nature of the power supply to achieve low load or overload work of the compressor, and at the same time adjust the throttling capacity of the refrigeration system. In order to achieve this change in power and throttling, many complicated links need to be added in the middle. Therefore, the disadvantage of this adjustment method is that it is prone to failure in actual use.

2. Chilled water type unit: The principle is to use cold water at around 7°C as the cold source, and the cooling capacity is adjusted by controlling the water flow. This method is simple to operate, not prone to failure, and the control effect is the most stable. Before using this unit to control the temperature, it is necessary to accurately calculate the heat and humidity load and air dew point in each room of the laboratory, so as to match the appropriate air volume, cooling capacity, heating capacity, and humidification capacity. Generally, PLC is used to control the stepless regulation of each component, equipped with sensors with good sensitivity and high performance, which can achieve a temperature of ±0.5°C and a humidity of ±2%. In addition, before it is put into use, it is necessary to match the unit according to the area and load of each laboratory room, so it is generally a custom combined unit. The disadvantage of this adjustment method is that it covers a large area, the stability of the system is not good enough, and the later maintenance and repair are more difficult.

IV, the fresh air system designed by the constant temperature and humidity laboratory

The main function of the fresh air system is to provide clean air for the experimental site while maintaining the stability of laboratory temperature and humidity. In order to ensure that the laboratory system is stable and not disturbed, the constant temperature and humidity laboratory design must install a fresh air system to keep the air pressure in the laboratory at a positive pressure to prevent outside air from entering the laboratory and affecting the constant temperature and humidity. In the design of a clean laboratory, the fresh air system plays a greater role. We will continue to explain this point in future articles.

The above is about the air conditioning and fresh air system settings and technical principles of the constant temperature and humidity laboratory design. For more detailed analysis of laboratory design related knowledge, please click "Technical Support" to view.