2.
According to the relevant requirements of the literature, the sample preparation area: “aerosol pollution from the adjacent area into the area can be avoided by establishing positive pressure conditions in the area”; Expansion area: “the air pressure in this area can be reduced to avoid aerosol leakage from this area”; Amplification product analysis area: “the possibility of amplification products diffusing from this area to the front area can be reduced under negative pressure or reduced pressure (such as installing exhaust fan).
During the epidemic period, the PCR experimental area is set up with reference to the enhanced medical BSL-2 laboratory.
In general, only one PCR laboratory is configured in the laboratory of the hospital, so the air conditioning and ventilation system of the PCR laboratory with the combination of peacetime and epidemic disease is very important.
According to the pressure difference required by the design and the gap method in the code for design of clean buildings (gb50073-2013), the room infiltration air volume that maintains the room pressure difference can be obtained..
3.3 air distribution and pressure difference control PCR the air distribution of each laboratory adopts the method of upper supply and lower discharge.
The project takes into account the needs of combining the epidemic and the epidemic.
The fresh air mode is used to purify the air conditioning system, as shown in Fig.
3.2 local exhaust design: the specimen preparation area (area II) is equipped with a class II B2 biological safety cabinet (100% external exhaust), and the corresponding independent variable air volume fresh air system is set.
The high-efficiency air supply outlet shall not be set above the operation points where aerosol is generated, such as the operation surface of the biological safety cabinet, to avoid aerosol diffusion.
The variable-frequency exhaust unit (with coarse effect (C4) and electrostatic photocatalysis medium effect (Z3)) is set at the roof frame layer.
The indoor air outlet is set at the bottom of the room, and the high-efficiency filter is set at the air outlet (plate type primary effect filter is set in front of the air outlet to protect the end high-efficiency filter (class B) and extend its service life).
The specific pressure gradient requirements in normal time (non epidemic time) are zone I (10Pa) → zone II (8PA) → zone III (- 10Pa) → Zone IV (- 15pa), as shown in Figure 1.
According to the provisions of the specification [2] [3], in order to reduce the pollution to the staff and the environment, the air conditioning and ventilation systems in areas II, III and IV are all set up in accordance with the requirements of the enhanced medical BSL-2 laboratory under the epidemic situation.
The standard for determining the design parameters of the air conditioning room in the PCR experimental area: the PCR combined laboratory includes four zones according to the work flow: reagent storage and preparation zone (zone I), sample preparation zone (zone II), amplification reaction mixture configuration and amplification zone (zone III), amplification product analysis zone (Zone IV), supplemented by buffer rooms and internal corridors in each zone, Constitute a complete PCR experimental area (areas II, III and IV all meet the relevant requirements of biosafety level II laboratory [1]).
The air outlet of the high-efficiency filter is set in the area with the highest risk of indoor pollution.
2.
The PCR experimental area meets the requirements of class 8 cleanliness (class 100000).
It can be seen that the aerosol in the test sample of severe respiratory infectious disease virus also has strong infectivity.
A virus detection laboratory with perfect air conditioning and ventilation system can not only protect medical personnel, but also prevent the leakage of harmful viruses, which plays an important role in epidemic prevention and control.
The experimental area is provided with a comprehensive exhaust system with coarse, medium and high air filtration systems.
1.
The makeup air volume is taken as the exhaust air volume of the biological safety cabinet to avoid the indoor pressure change caused by the use of the safety cabinet.
However, many people are still infected with novel coronavirus (a class B infectious disease with reference to class A infectious diseases for which preventive and control measures are taken).
3.
It is arranged in a barrier free one-way manner to minimize the stagnation of indoor air flow.
The pressure gradient requirements and air conditioning and ventilation system settings of the traditional virus testing laboratories in conventional hospitals cannot provide complete protection for medical personnel when detecting severe respiratory infectious viruses.
It can be seen that the working flow of PCR laboratory is one-way streamline transmission, and the air flow direction is also strict single direction.
According to the requirements of various specifications, the design parameters of the air conditioning room in the PCR experimental area at ordinary times (epidemic times) are obtained, as shown in Table 1.
Air conditioning and ventilation design of PCR experimental area due to the construction cost and operation cost, the traditional medical PCR laboratory generally does not use clean air conditioning system, and there are no requirements for cleanliness, minimum ventilation times and minimum pressure difference.
The laboratory technicians of the hospital’s laboratory department do not directly contact the patients, but only do tests and tests.
Project overview the virus detection in the hospital is carried out in the PCR Laboratory (PCR laboratory is the clinical gene amplification test laboratory, which refers to the laboratory that performs disease diagnosis, treatment monitoring and prognosis judgment by amplifying and detecting specific DNA or RNA).
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3.1 the air conditioning system is designed to adopt two pipe fresh air frequency conversion purification air conditioning units, and the fresh air is sent into the room after heat and humidity treatment and coarse, medium and high air filtration.
In order to actively respond to the prevention and treatment of novel coronavirus pneumonia, the PCR Laboratory of a Chinese medicine technology building was redesigned and upgraded to meet the requirements of combination of epidemic prevention and treatment.
Reasonable building functional zoning, special equipment joint control device, pressure gradient, air distribution and ventilation control strategy are important guarantees to avoid contamination of reagents and samples in PCR experiments and false positive test results.
The first stage coarse efficiency (C4) is set at the fresh air inlet of the air conditioning unit; The second stage electrostatic photocatalysis medium efficiency (Z3) is set at the outlet of the air conditioning unit; The third level efficient air supply outlet (Class A) is set at the end of the air supply system (laboratory ceiling).
The specific pressure gradient requirements during the epidemic are as follows: area I (10Pa) → area II (- 10Pa) → Area III (- 15pa) → Area IV (- 20Pa), as shown in Figure 1.
