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In this paper, a numerical simulation study of the airflow organization and aerosol diffusion process in a typical isolation ward is carried out to explore the effects of mixing ventilation (MV) and perforated ceiling air supplying ventilation (PCV) strategies on aerosol diffusion and deposition in the ward. Furthermore, the effects of aerosol particle size (5μm, 20μm) and aperture ratio of perforated plate on aerosol distribution were studied in this paper. The simulation results show that: compared with the MV case, PCV results in a more uniform flow field and temperature field in the ward, and can increase the discharge speed of aerosol particles, which can effectively reduce the risk of cross-infection among medical staff; by counting the proportion of aerosol deposition, discharge and suspension on each surface in the ward, it can be found that small-sized aerosol particles (5μm) are more likely to diffuse and suspend in the ward under the influence of the flow field, while large-sized aerosol particles (20μm) are more likely to be deposited on the ground and on the bed under the influence of gravity; when using PCV, reducing the porosity of perforated plate can accelerate the deposition and discharge of aerosol particles, reduce the suspension of particles in the ward, and reduce the risk of virus infection in the air．

In the air-conditioning system, a high-efficiency air filter can guarantee the capture of dust and biological particles. However, the traditional filter material itself does not have the function of disinfection and self-purification. As a result, the traditional air filter might become a hotbed for the reproduction of the microorganisms. Carried by the airflow, these microorganisms can enter the indoor environment, which might cause secondary pollutions. A properly selected upstream filter can prevent the particulate pollution, while it is hard to prevent the biological pollution inside the air-conditioning system. The microwave radiation is a broad-spectrum and high-efficiency disinfection method because of its disinfection mechanism, penetrability and selective heating property. At present, the microwave disinfection technology is widely used in the disinfection process of food processing, but its application in the air-conditioning field is relatively rare. From this point of view, this paper proposes to apply the microwave disinfection technology to the filters of the air-conditioning system. First, the combination of the filter and absorbing material is proposed to improve its absorption capacity of the microwave. Then, the air-conditioning system experimental platform for microwave disinfection was established and experiments were carried out to explore the disinfection effect of the Staphylococcus aureus on the composite filter under the microwave radiation. Finally, the experimental results and their influencing factors are briefly analyzed.

The demand of building energy management has increased due to high energy saving potentials. Load monitor and disaggregation can provide useful information for building energy management systems with detailed and individual loads of the building, so corresponding energy efficient measures can be taken to reduce the energy consumption of buildings. The technique is investigated widely in residential buildings known as Non-Intrusive Load Monitoring (NILM). However, relevant studies are not sufficient for non-residential buildings, especially for the cooling loads. This paper proposes a NILM method for cooling load disaggregation using artificial neural network. The cooling load is disaggregated into four categories: building envelope load, occupant load, equipment load and fresh air load. Two approaches are used to realize the load disaggregation: one is based on the Fourier transfer of the cooling loads, the other takes the cooling load, dry-bulb temperature and humidity of outdoor air, and time as inputs. By implementing the methods in a metro station, the performance of the proposed method can be obtained. Results show that both approaches can realize the load disaggregation accurately, with a RMSE less than 11.2. The second approach is recommended with a higher accuracy.

Phase change material (PCM) can be used in building envelope for heat insulation and energy-saving. However, the energy-saving effect of the PCM wall system is limited in summer since the PCM storing heat in the daytime will become a secondary heat source and release heat into the room again at night. This paper proposed a novel pipe-encapsulated PCM wall system. It integrates phase change technology and nocturnal radiation cooling technology together to realize building insulation and active heat removal. A simulation platform is established for the thermal performance simulation of this wall system. It mainly includes the simplified pipe-encapsulated PCM wall model and nocturnal radiation model. The simplified wall model includes the 5R2C wall model, 4R2C PCM model and 2R1C pipe model. The model parameters are identified and the model is also validated with good accuracy. Based on this platform, the thermal performance of a light weight room with pipe-encapsulated PCM wall system in Wuhan is simulated. About 50%-60% of heat from the outdoor environment can be conserved by the pipe-encapsulated PCM wall, and 50% of that can be removed by the radiant cooler at night. Results show the pipe-encapsulated PCM wall system has good thermal performance for light weight building.