WS/T 696-2020Hygienic specifications for the operation and management of air conditioning and ventilation systems in office and public places during the COVID-19 epidemic (English PDF)

5.1 All-air air conditioning system

5.1.1 Preparation before opening

5.1.1.1 The source of fresh air and the scope of air supply should be mastered. When the type of air-conditioning and ventilation system, the range of air supply, etc. are unclear, it should Turn off the air conditioning system at time.

5.1.1.2 Check whether the filter, surface cooler, heating (humidifier) and other equipment are operating normally, and whether the inner surface of the air duct is clean. response Equipment and components such as open cooling towers and air handling units shall be cleaned, disinfected or replaced. Respond to the inner surface of the air duct and air supply sanitation the quality is tested, and it can be operated only after being qualified.

5.1.1.3 The fresh air outlet and its surrounding environment should be kept clean and the fresh air should not be polluted.

5.1.1.4 The short-circuit problem of the fresh air outlet and exhaust outlet or the hidden danger of short-circuit under occasional weather conditions should be investigated. If unable to enter in the short term If the physical location is rectified, the air conditioning and ventilation system should be turned off.

5.1.1.5 Before turning on the fresh air system in winter in cold areas, ensure that the freeze protection function of the unit is safe and reliable.

5.1.2 Management and maintenance during operation

5.1.2.1 Low-risk areas should be operated with the maximum fresh air volume, and the return air should be turned off as much as possible; medium and high-risk areas should be closed, such as return air the air outlet (pipeline) or air-conditioning box is in use with a high-efficiency and above-grade filter device, or an effective disinfection device is installed, and the return air can be turned off. Such as it has a mixed air structure. The mixed air components of the system should be closed before opening, and the mixed air mode should be stopped.

5.1.2.2 When air conditioning and ventilation systems are used in crowded places, indoor air flow should be enhanced; windows, doors, or fans should be opened Wait for the ventilation device, or use natural ventilation for 20 minutes to 30 minutes every 2 hours to 3 hours in the air conditioner.

5.1.2.3 For shopping malls, office buildings and other places with a large flow of people, the ventilation should be strengthened;

The fresh air and exhaust system of the ventilating system should be operated in advance or closed for 1 h after a delay.

5.1.2.4 The sanitary management of condensate water such as air handling units and fan coils, and cooling tower cooling water should be strengthened.

5.1.2.5 The filters, vents, air handling units, surface coolers, heaters (humidifiers), Equipment and components such as the condensate pan should be cleaned, disinfected or replaced.

5.1.2.6 U-shaped pipes such as sewer pipes, air handling devices, bathroom floor drains, and condensate drain pipes of air conditioning units shall be inspected weekly.

Water seal, replenish water in time when water is lacking.

5.2 Fan coil plus fresh air system

5.2.1 Preparation before opening

5.2.1.1 The air-conditioning ventilation system that is unclear such as the type of air-conditioning, the source of fresh air or the range of air supply should be temporarily closed.

5.2.1.2 Check whether the filter, surface cooler, heater (humidifier), fan coil and other equipment are operating normally. For open cooling towers, Equipment and components such as air handling units and condensate pans shall be cleaned, disinfected or replaced. Deal with the inner surface of the air duct and the sanitary quality of the air supply Carry out the test, can run after passing.

5.2.1.3 It should be ensured that the fresh air is taken directly from the outdoors, and it is forbidden to take the air from the machine room, corridor and ceiling. Ensure that the new air outlet and its surroundings the environment is clean, and the fresh air is not polluted.

5.2.1.4 The fresh air system should be turned on 1 h before the opening of the site.

5.2.1.5 The short-circuit problem of the fresh air outlet and exhaust outlet or the hidden danger of short-circuit under occasional weather conditions should be investigated. If unable to enter in the short term If the physical location is rectified, the air conditioning and ventilation system should be turned off.

5.2.1.6 The normal operation of the exhaust system shall be ensured.

5.2.1.7 For rooms with a depth of >=14 m, measures should be taken to ensure ventilation in the internal area; if the fresh air volume is insufficient, it should be less than 30 m3/(H. People) National standards require that the density of personnel should be reduced.

5.2.1.8 Before turning on the fresh air system in winter in cold areas, ensure that the freeze protection function of the unit is safe and reliable.

5.2.2 Management and maintenance during operation

5.2.2.1 The ventilation of public places with a large flow of people should be strengthened; before or after the business day, it should be opened or pushed in advance.

Turn off the air-conditioning system 1 h late.

5.2.2.2 The frequency of ventilation in densely populated office places should be increased. When the air-conditioning ventilation system is used, windows, doors or openings should be opened.

Ventilation devices such as fans, or natural ventilation for 20 minutes to 30 minutes every 2 hours to 3 hours of operation of the air conditioner.

5.2.2.3 The sanitary management of condensate water and cooling water of the air conditioning and ventilation system shall be strengthened.

5.2.2.4 Equipment and components such as cooling towers, air handling units, air supply outlets, condensate pans, etc. of the operating air conditioning and ventilation system shall be installed weekly.

Clean, disinfect or replace.

5.2.2.5 The water seals of U-shaped pipes such as sewer pipes, air handling devices, bathroom floor drains, etc. shall be inspected weekly to replenish water in time to prevent failure Air mixing on the same floor.

5.3 Split air conditioner

5.3.1 Preparation before opening

Clean the air conditioner indoor unit filter with clean water, and clean and disinfect the air conditioner radiator when possible.

5.3.2 Management and maintenance during operation

5.3.2.1 Before using the split air conditioner every day, the doors and windows should be opened for ventilation for 20 to 30 minutes, and then the air conditioner should be turned on and adjusted to the maximum air volume After running for at least 5 minutes, close the doors and windows; after the split air conditioner is turned off, open the doors and windows for ventilation.

5.3.2.2 For long-term use of split-type air conditioners and densely populated office places, the air conditioner should be ventilated for 20 minutes to 30 minutes every 2 hours to 3 hours.

min.

5.4 Fan-coil system or multi-line system without fresh air

5.4.1 Preparation before opening. Each independent temperature control space without fresh air fan coil system or multi-line system should be checked, and the air supply and return air are Whether it has a closed air duct connected to the surface cooler to avoid taking back air from the connected ceiling. Fan-coil system or multi-line system without fresh air the cleaning and disinfection shall meet the requirements of 5.3.1.

5.4.2 The management and maintenance during operation shall meet the requirements of 5.3.2.

5.5 Other operation management requirements

The air conditioning and ventilation system should also meet the requirements of current national standards such as GB 50365 and GB 50736.

5.6 Decommissioning of the air conditioning system

When a confirmed case of new coronary pneumonia, a suspected case, or an asymptomatic infection occurs, the following measures should be taken.

a) Immediately shut down the air-conditioning and ventilation system corresponding to the active area of confirmed cases, suspected cases or asymptomatic infected persons;

b) Under the guidance of the local disease prevention and control agency, immediately disinfect and clean the air conditioning and ventilation systems in the above-mentioned areas.

It can be reopened after passing the hygiene inspection and evaluation.

5.7 Hygienic evaluation, cleaning and disinfection of air-conditioning systems

The hygienic evaluation, cleaning and disinfection of air conditioning and ventilation systems in public places shall meet the requirements of WS/T 395 and WS/T 396.Office places the hygienic evaluation, cleaning and disinfection of air conditioning and ventilation systems can be implemented in accordance with the requirements of WS/T 395 and WS/T 396.

6.1 Daily inspection

6.1.1 Collect basic information about the air conditioning and ventilation system, including the type of air conditioning and ventilation system, air supply area, design parameters, and the number of cooling towers Amount, disinfection method, etc.

6.1.2 Check the integrity of the sanitation management system and sanitation management files.

6.1.3 Whether the new air outlet is equipped with a protective net and primary effect filter, and whether it is far away from the exhaust outlet of the building, open cooling tower and other pollution source.

6.1.4 Whether the air supply outlet and return air outlet are equipped with anti-mouse devices and clean them regularly to keep the surface of the air outlet clean.

6.1.5 Does the unit have devices for emergency shutdown of return air and fresh air, devices for controlling the sub-regional operation of the air-conditioning system, etc., and can they be normal?

run. Air handling unit, air supply pipe, return air pipe, fresh air pipe, filter screen, filter, purifier, air outlet, surface cooler, heating Whether the (wet) device, condensate pan, etc. are cleaned and kept clean as required.

6.1.6 Whether the air handling room is clean and dry, and whether irrelevant items are stored.

6.1.7 Hygienic quality inspection report of cooling water, condensate water, fresh air volume, air supply, and inner surface of air duct of air conditioning system.

6.2 Hygiene monitoring

6.2.1 The hygienic monitoring index and result judgment of the air conditioning and ventilation system in public places shall meet the requirements of WS 394.

The wind system hygiene monitoring index and result judgment can refer to the requirements of WS 394.

6.2.2 The hygienic inspection method of air conditioning and ventilation systems in public places shall meet the requirements of GB/T 18204.5.

The sanitary inspection method can be implemented according to the requirements of GB/T 18204.5.