Performance evaluation of personalized ventilation personalized exhaust (PV PE) system in air conditioned healthcare settings 9

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Performance evaluation of personalized ventilation   personalized exhaust (PV PE) system in air conditioned healthcare settings 9

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Chapter 9: Conclusions and Recommendations 9.1 Review and Achievement of Research Objectives This study has evaluated the feasibility and performance of a novel PV-PE system in the protection of a Healthy Person (such as a doctor) and in the ventilation control of airborne infectious disease induced by exhaled contaminated air from an Infected Person (such as a patient) in mock-up consultation rooms in healthcare centres. The three specific objectives of this research and the achievements are reviewed below: First Objective The first objective was to “Evaluate the potential of a PE device to enhance the performance of a PV device in terms of pulling the PV conditioned outdoor air towards a Healthy Person”. The conclusions from the study related to this objective are summarized as follows: • For the same PV flow rate and manikin location, the personal exposure effectiveness increased with the increase of the PE airflow rate for most of the cases. One exception was when PV was supplying fresh air at 10 l/s with a 0.2 m distance from the manikin. In this scenario, the combined PV-PE did not help with the pulling effect because the PV could deliver the conditioned outdoor air to the breathing zone with a high momentum and short distance. • When the manikin was moved longitudinally along the centerline of PV ATD, the PV fresh air could still reach the breathing zone. However, when the manikin was moved in an arc away from the centreline of the PV ATD, the amount of PV air in the inhaled air dropped quickly to 0. • After adding the PE device, with both MV and DV conditions, the PE was able to divert the PV air to some extent. The larger distance and degree were achieved with DV compared with MV because the relative higher room air velocity with MV tends to disturb the local environment created by PV-PE. When PE was set at 20 l/s, the effective area could be enlarged to 45 degree for all the cases with DV and up to 60 degree for a short distance of 0.2 m. • During a normal consultation process in healthcare centres, where the Infected Person and the Healthy Person are sitting face to face, the results indicated that the combined PV and PE for HP could achieve the highest PEE. It was also observed that the shoulder-PE performed a little better than top-PE in terms of increasing the PV air in the inhaled air. • The above-mentioned conclusions imply that when a Healthy Person is working in a consultation room or a health care setting room, the use of combined PV-PE for the Healthy Person could provide more fresh air than PV alone, which can contribute to the infectious control during or after a consultation and check-up procedure with an Infected Person. Second Objective The second objective was to “Determine the effectiveness of airborne infection control of the combined PV-PE system in conjunction with background MV or DV systems in terms of the localized extraction of the contaminated exhaled air from an Infected Person in healthcare settings”. Three scenarios were considered for this objective, as shown below: a Infected Person seated facing the seated Healthy Person b Infected Person seated under two different configurations by the side of the seated Healthy Person c Healthy Person standing facing the seated Infected Person Important conclusions from the study related to this objective areas follows • In the context of airborne transmission control when the HP and IP are sitting face to face, the use of PV alone has a potential to protect the HP; the use of combined PV-PE alone for HP could achieve the lowest Intake Fraction. The use of PE for IP alone showed much better performance than using PV for HP alone. However, after activating the PE for IP, the use of PV for HP was observed to lead to higher or lower exposure. The increase or decrease depends on the effects of background ventilation type, PE type and PV flow rates. • For better airborne transmission control, top-PE is preferred than shoulder-PE because it could achieve better exposure reduction and lower intake fraction with ường hay mặc cảm, tự ti, rụt rè tham gia hoạt động tập thể. - Đối tượng 3: Học sinh thuộc gia đình giả - Đa số em gia đình chăm lo, quan tâm giám sát việc học tập nhà em tốt, học sinh thuộc đối tượng em cán công nhân công ty cà phê 719 cán CNVC nhà nước. Do vậy, em phần lớn chăm ngoan có kết học tập loại trung 15 bình đến em: Long, Thuỷ, Dung, Quyết Chiến, Duy Cường, Phan Huy, Đức Dũng… Có thể nói, chất người, dù học sinh học yếu, hay hạnh kiểm chưa tốt có mặt tốt, mặt nhân tính, ước mơ, nguyện vọng thầm kín đáng đầy nhân hồn nhiên. Các em thích khen ngợi, yêu thương. Nếu nhà trường gia đình nắm nguyên nhân sâu xa, có đồng cảm hiểu em, có thống phương pháp giáo dục chắn giúp em học tập tốt năm cuối cấp định hướng đắn chuẩn bị bước vào tương lai. Vì thế, tùy theo đối tượng để vận dụng biện pháp giáo dục phù hợp. III. Các biện pháp giáo dục 1. Biện pháp thứ nhất: Giáo dục trực tiếp, gần gũi hoàn cảnh trực tiếp em có biện pháp linh hoạt với em. Đây học sinh ngoan, học tốt, nòng cốt lớp. Nhưng giáo viên chủ nhiệm thường xuyên gần gũi em để nắm bắt thông tin lớp, thông qua em để nắm thông tin tiết học môn sinh hoạt tập thể. Tôi tỏ thái độ tin tưởng với đội ngũ cán lớp, giao trách nhiệm cho lớp trưởng nắm bắt tình hình chung lớp ngày, lớp phó học tập ghi lại vấn đề học tập cũ, mới, tập , Ngoài có tổ trưởng theo dõi sát tổ viên để báo cáo kịp thời. 2. Biện pháp 2: Giáo dục thông qua hoạt động tập thể - Vào ngày lễ, sinh hoạt chủ nhiệm lớp thường tổ chức cho học sinh tham gia hoạt động tập thể như: Tìm hiểu ngày truyền thống 20-11, Hái hoa dân chủ, Tìm hiểu tâm lí tuổi lớn, Ngày mẹ em nên làm gì?, - Tổ chức hoạt động GDHN, GDNGLL giúp em có nhìn tổng quan giới nghề nghiệp, định hướng tương lai chọn nghề cho phù hợp với lực, sở trường, điều kiện gia đình, thân… Tôi phân công ban cán 16 lớp làm công tác tổ chức. Còn tùy theo khả đối tượng lớp để phân cnhiệm vụ khác nhau. Và lớp tổ chức tốt hoạt động ngoại khoá trên. 3. Giáo dục thông qua hình thức kết bạn: - Lập đôi bạn tiến. Động viên em khá, giỏi kèm cặp, giúp đỡ bạn yếu kém. Các em vừa giúp đỡ học tập vừa giúp tinh thần, tránh cho bạn mặc cảm. - Chọn bạn giúp đỡ học sinh khá, giỏi cán lớp, nhiệt tình với bạn có trách nhiệm việc giúp đỡ thành viên lớp tiến bộ. - Lên kế hoạch giúp đỡ, tổ chức họp nhóm nhà. 4. Giáo dục kết hợp với Hội cha mẹ học sinh cha mẹ học sinh: "Nhà trường, gia đình xã hội có vai trò giáo dục khác hình thành phát triển phẩm chất trị, đạo đức, lối sống củthcare environments, depending on the target value of the Intake Fraction (iF). Energy saving implication is evaluated in this study and a few recommendations can be drawn from this study to save energy. In addition, the concept of PV-PE system is not only applicable to consultation rooms in healthcare settings but also to some other potential environment such as offices. The ability of PE to divert the PV air can be applied in any place with PV installed for better inhaled air quality. The advantage of PE for infection control can be applied in any open area with the presence of an Infected Person. 9.3 Limitation of the study The experiments performed and reported in Chapter were limited to only a few of the many possible manikin locations and flow rate conditions that would occur in practice. The PV and room air temperature were kept at 23 °C through all the experiments. However, the change of PV air temperature and room air temperature may also affect the performance of the local environment created by the PV-PE system. In the CFD study, constant continuous inhalation/exhalation was used for the manikin instead of cyclic variations in the velocities of respiratory breath. This may lead to a difference of the results especially for the exhalation case. The study focuses on normal exhalation process with small diameter of droplets. The results of this study cannot be applied to larger droplets with different scenarios such as coughs and sneezes . Lastly, there is a draft risk (Draft Rating is more than 15%) potential after using the PE. Further investigation on the users’ acceptability of PE may be interesting. 9.4 Recommendations for Future Work 9.4.1 Recommendation on Scientific Research Firstly, in the present study, the objective is mainly focussed on the feasibility of the integrated PV-PE system, driven primarily by experimental work involving objective measurements. Its practical applicability and user acceptability in real healthcare settings are recommended for the thermal comfort, draft rating and inhaled air quality aspects. Further optimisation of the PV-PE system integrated with background systems (such as MV or DV) in actual healthcare settings and other application areas would also be possible. Theusers’ preference of different types and locations of PE is yet another dimension worth exploring. In this study, only MV and DV are examined in the experiments. For further research, the performance of the novel system in rooms with other background ventilation systems, i.e. UFAD or downward ventilation systemcan be evaluated. In the present study, the indoor temperature level was controlled at 23°C for all experimental cases. The effect of different room air temperature on the objective measurement of the transmission of exhaled air and subjective responses when PE is applied might be worth exploring. The individual control with larger range of PE air flow rate is another possible dimension to explore. It is recommended that the performance of the novel PV-PE system should be studied with the inclusion of more realistic scenarios such as a third person walking in the immediate vicinity, and changes in the postures of either IP or HP, changes in the skin temperatures of the IP (eg, IP with fever). Lastly, further optimisation of energy saving potential of the PV-PE system integrated with background air conditioning and air distribution systems with full scale energy measurements is also worth exploring. 9.4.2 Recommendation on Technology Development The PE outlet mounted either on top or at shoulder level can be further developed that can slide not only up and down according to a person’s height but also forward or backward. This may cater for the varying “sitting” posture of an Infected Person. Moreover, the PE outlet used in this study is some basic round outlet with damper, through which the air is sucked in a straight line parallel to the axis. Perforated panel or other designs could be tested. However, the design of the PE outlet needs to be carefully justified, since it might affect the flow characteristics, suction efficiency and consequently the contaminant distribution. The results presented in this thesis may not be directly applicable to a different configuration of the PE outlet.   . doctor) and in the ventilation control of airborne infectious disease induced by exhaled contaminated air from an Infected Person (such as a patient) in mock-up consultation rooms in healthcare. is when HP is standing, facing the seated IP. In the context of airborne infection control in healthcare settings, this novel PV-PE system is developed to help with the ventilation design which. conjunction with background MV or DV systems in terms of the localized extraction of the contaminated exhaled air from an Infected Person in healthcare settings . Three scenarios were considered

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