This paper is helpful for designers to understand the particularity of the air conditioning system requirements of the general hospital laboratory, and clarify the design ideas for the air conditioning system design of the laboratory.
1. The laboratory should not be equipped with common air-conditioning terminal units. The state has strict regulations on the setting of laboratories with biological hazards in the laboratory. The biosafety protection laboratory is classified according to level I-IV. the higher the level is, the higher the laboratory protection requirements are. General hospitals (except infectious disease hospitals) generally set up level II biosafety protection laboratories, which must be equipped with level II biosafety cabinets. All operations that are easy to produce aerosol or spill pollution must be completed in the cabinets. The biosafety cabinet is a box type air purification safety device used in the treatment of dangerous microorganisms. Its principle is a local exhaust hood with high efficiency filter which can purify the exhaust air.
When working, the front glass sliding window is half opened, the working area is negative pressure, and the external air is sucked in by the operating window and cannot escape, which not only ensures that the staff are not infringed, but also ensures that the experimental object is not polluted. It can be seen that the correct use of biosafety cabinet can effectively reduce the cross infection of new infection and culture caused by aerosol exposure, and can protect the environment. It should be noted that in order to avoid external pollution of the specimen, the air sucked into the safety cabinet must be clean air. If the end of ordinary air conditioner (such as fan coil or cabinet type air conditioner) is used, it is difficult to install the filter device to purify the air out of the air conditioner, so this kind of unit is not suitable for use in the protection laboratory, and the most ideal end should be the air treatment unit with coarse, medium and high filtration.
2. The air conditioner of the laboratory should be set up in different areas and independently to maintain a reasonable air flow direction. The air conditioning system of the laboratory should be separated from the air conditioning system of the hospital in order to prevent and avoid cross infection. In addition, the air conditioning system should be set up separately in the internal area of the laboratory. For non polluted areas such as office area, fan coil system can be used for cost consideration, but auxiliary air purification unit shall be set, and indoor air shall be disinfected and purified regularly. The experimental area (including buffer area) should be equipped with a full air system with coarse, medium and high-level filtration. Its air return and air supply outlets should be arranged inside the laboratory and should not be connected with the outside, so as to keep the clean area and pollution area separate.
The primary filter of the air handling unit shall be set in the negative pressure section of the unit, and the primary filter shall also be set at the new air outlet; the medium efficiency filter shall be set in the positive pressure section of the air handling unit; and the high efficiency filter shall be set at the end of the system. In addition, a medium efficiency filter for protection should be set in front of the surface cooler for the new air system; effective rainproof measures should be taken at the inlet of the new air, and protective nets for rat proof, insect proof and fluff proof should be installed, which are easy to disassemble.

The fresh air volume in the office area shall not be less than 4 ventilation times per hour, and the ventilation times in the experimental area shall not be less than 12 ventilation times per hour. In terms of air distribution, in order to ensure that the air flow in the laboratory flows from the clean area to the polluted area, the exhaust layout with uniform distribution on both sides should not be used in the laboratory, and the ventilation design of up supply and up exhaust should not be used. The air supply and exhaust mode should be adopted, and the arrangement of air supply outlet and exhaust outlet should be conducive to the discharge of indoor air that may be polluted. The installation position of the biosafety cabinet should be far away from the entrance of the experimental room, avoid the area where the staff frequently walk, and be conducive to the formation of the air flow pattern from the "clean" area to the "polluted" area. Air supply outlets shall not be set near the operation surface of biosafety cabinet or other places where aerosol is generated. The exhaust system of laboratory room and experimental equipment (such as biosafety cabinet) must share the same exhaust system, otherwise it will greatly increase the difficulty of eliminating room positive pressure.

3. Consider the operation of air conditioning system in the transitional season. Because the laboratory has a large number of precision testing equipment, which has large heat output and high temperature requirements; in addition, there are relatively more indoor staff in the laboratory, so the air conditioning system of the laboratory has a large load, even in the transitional season, it still needs air conditioning operation. In addition, in order to maintain the pressure of some laboratories, the fresh air unit must also be operated continuously in the transitional season. Therefore, there is a certain contradiction between the operation time of the air conditioning system in the laboratory and the operation time of the whole building air conditioning system in the hospital. If the cold and heat sources of the laboratory air conditioning can not be set separately, the outdoor fresh air volume shall be increased in the transitional season to maintain the indoor temperature, humidity and cleanliness requirements of the laboratory. For laboratories without external windows, it is better to set up standby fresh air units. The air volume of the standby unit should be based on the calculation of the enthalpy and humidity required to maintain the indoor temperature and humidity in the transitional season. It is not allowed to blindly increase the estimation of the new air volume, because the larger the new air volume is, the better. Some literatures believe that the new air volume is from 25% to 100%, which is no difference for the sick building complex, and will cause the cost waste of the transitional season operation.
Shandong ed purification Engineering Co., Ltd. is a professional hospital clean operating room, ICU, disinfection supply room, blood purification center, vein distribution center, disease control center, digital integrated operating room, intervention operating room, positive and negative pressure operating room, radiation protection, obstetrics, infant ward, burn ward, hemodialysis room, laboratory, pathology department, plastic surgery room The business scope of such high-tech enterprises as purification engineering mainly covers the design and construction of Medical Building Decoration Engineering, central air conditioning engineering, electrical engineering, intelligent engineering, water supply and drainage engineering, gas engineering, etc. The company integrates professional scheme design team, complete supporting product channels, professional system construction team and perfect after-sales service. With the relevant construction qualification issued by the national construction department; with an experienced engineering technology research and development team; with years of professional accumulation in the field of purification, combined with the construction management practice of many domestic projects, to provide comprehensive and high-quality overall purification system technical support for domestic customers. If you want to know more about the workshop purification construction, please contact the engineering personnel of the project department in detail. For more knowledge of medical purification industry, please pay attention to wechat public number: aide-188 (ED purification oxygen supply)