Study On Long-term Performance And Purification Effect Of Wall-mounted Fresh Air System

At present,more and more consumers choose fresh air system as a means to improve indoor air quality.But the performance of the filter in the fresh air system and the performance of the system will change.This study conducted market research on the mainstream fresh air system,built single-through test pipelines,monitored the long-term performance of wall-mounted fresh air system and different filters in the actual use environment,and provided experimental basis for the maintenance of filter elements.Through the experiment,the relationship between the ventilation frequency of fresh air and the permeability ventilation frequency is obtained,which provides a basis for the modification of the purification model of a fresh air system.The main research conclusions are as follows:(1)The purification technology of the fresh air system mainly includes HEPA and electrostatic technology.100%of fresh air systems use HEPA filtration technology,and more than 90%of fresh air systems are equipped with primary filters.The most common combination of filters of the fresh air system is primary+(sub-)high efficiency.(2)In the laboratory experiment,the filtration efficiency of PP filter decreased by about 20%～30%after running for about a month.However,the filtration efficiency of the glass fiber filter did not decline but slightly improved.(3)The efficiency of the wall-mounted fresh air system does not decrease significantly during the long-term operation in the field.The change in fresh air volume in the system was significant,decreasing by 70%after 5 months.Comparing the long-term sensor data of the pipeline fresh air system and the wall-mounted fresh air system,it is found that the pipeline fresh air system is more likely to reduce the system efficiency due to the pipeline deposition.(4)For the purification model of the fresh air system,the influence of fresh air on the infiltration air volume should be considered.The relationship between the purifying effect of a new fan on a single area and the actual air volume increases linearly.When the fresh air system is 60～113m~3/h,the purifying effect of the adjacent chamber is70～80%of that of the main chamber,and the greater the air volume,the greater the difference of the purifying effect between the two Chambers.