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The Influence of a Moving Object on Air Distribution in Displacement Ventilated Rooms

The Influence of a Moving Object on Air Distribution in Displacement Ventilated Rooms As is well known, a moving person affects the stratification of indoor air and enhances the mixing in ventilated rooms with a displacement ventilation system. This paper describes the effect of moving object on the performance evaluation of displacement ventilation, by means of an experiment using a movable heated human model in a full scale room model. Distributions of air temperature and tracer gas concentration were measured to investigate the effect of the moving object’s direction, mode and speed on distribution of air in the room, and ventilation effectiveness. As a result of experiment, the moving object mode and speed showed a significant effect on the air temperature distribution and ventilation effectiveness. Keywords: displacement ventilation; moving object; full-scale experiment 1. Introduction breathing on the vertical contaminant distribution, and To keep thermal stratification is one of the most on the personal exposure of occupants (Bjorn et. al, important factors in controlling and maintaining good 1997). air qualityand high efficiency ventilation performance The above studies are not necessarily enough to in displacement ventilated rooms. However, physical resolve the mechanism and ventilation effectiveness of activity, like a moving person in the actual room has displacement ventilation as affected by human activity. been found to influence the stratification of indoor air Therefore the objective of this paper is to obtain and the performance of the ventilation system. This paper fundamental data by experimentation to clarify the describes the effect of a moving object on the mechanism of displacement ventilation in conjunction performance evaluation of displacement, through an with a moving object such as human activity in rooms. experiment using a movable heated human model, In this study the measurements were carried out using a designed to go back and forth on a straight line by means movable heated object controlled by an electrical slider of an electrical slider and a motion controller in a full and a motion controller in a full scale room model scale room model. Distributions of air temperature and (Nguyen et. al, 2002, Matsumoto et. al, 2002). The tracer gas concentration were measured to investigate distributions of air temperature, velocity and tracer gas the effect of the object’s direction of movement, mode concentration were measured for conventional systems and speed on the room air distribution and ventilation and displacement ventilation. The retest similar to the effectiveness. experiment done by Mattsson (1996, 1997) itself is seen Physical activity in a displacement ventilated room to be of value to the resolution of the moving object’s has been found to influence the performance of the effect. The originality of this study can be considered as ventilation system (Mattsson & Sandberg, 1994). The to investigate the influence of the object’s moving measurements of these studies were performed in a full direction and to develop an control system of an object scale test room, with a person simulator of cylindrical movement accurately to be compared with the results shape as the moving object (Mattsson et. al, 1996) and by the computational fluid dynamics (CFD) simulation also thermal mannequins (Mattson et. al, 1997). (Nguyen and Matsumoto, 2001). Furthermore full scale experiments were made in a displacement ventilated room with breathing thermal 2. Experimental Methods mannequins to study the effects of movements and A full scale room modelwith the dimensions 2.67x2.67x2.15m was used, along with a moving *Contact Author: Hiroshi Matsumoto, Toyohashi University of cylindrical object made of paper which was 1.2m high Technology, 1-1 Hibariga-oka, Tempakucho, Toyohashi 441-8580, and had a diameter of 0.3m. The room has a diffuser Japan with the dimensions, 0.3m high and 0.5m wide and an Tel: +81-532-44-6838 Fax: +81-532-44-6831 outlet, a hole with a diameter of 0.1m, located at 0.2m e-mail: matsu@tutrp.tut.ac.jp below the ceiling. The measurement points for (Received November 10, 2003 ; accepted April 6, 2004) temperature and concentration are shown in Figure 1. Journal of Asian Architecture and Building Engineering/May 2004/75 71 (1) (2) where τ is the nominal time constant, τ is the local mean s p age of air, C(t) is the normalized concentration, i.e. the actual value minus the supply air concentration, in time t, and C(0) is the normalized initial concentration The air change efficiency, ε , which evaluates the ventilation efficiency in a room, is defined by the following equations. Fig.1. Measurement system (3) The room was set up inside the laboratory of the Natural Energy Building, at the Toyohashi University of Technology, and was constructed with panels composed of 9mm plywood and 30mm insulation material on three sides and one side wall was made of 5mm acrylic glass. (4) The room was ventilated by a displacement ventilation system, and the moving object was designed to go back and forth on a straight line by a programmable controller and driver. The object was heated to simulate the heat where Ce(t) is the concentration of the exhaust air at flux of a human body, using a 100-watt bulb inside. time t, and <τ>is the room mean age of air. The temperature and tracer gas concentration, carbon The conditions measured here are shown in Table 1. dioxide, were measured by C-C thermo couples and a Two types of object movement were considered to multi gas monitor (B&K) respectively, to investigate the investigate the effect of different moving speeds on the temperature field and the ventilation effectiveness. The air distribution: perpendicular to the supply air flow and speeds of the object used were 0.0, i.e. standing still, along the supply air flow. The supply air flow rates for 0.4, 0.6, 0.8 and 1.0m/s. The moving modes were the former set of experiments (cases 1 to 5) were 35.7 controlled at a constant rate of acceleration or and 40m /h, and those for the latter set (cases 6 to 8) deceleration for the short time before and after the were 212.4 to 237.6m /h. The Archimedes numbers of stationary points and the constant speed in the middle the two sets were about 120 and 3 respectively. The as shown in Figure 2. supply air temperature was set to be 18 to 20 deg C during the experiments. 3. Measurement Results 3.1 Movement perpendicular to the supply air flow Figure 3 shows the measured carbon dioxide tracer gas concentration trends for the points ch1 to ch6 at 0.1m, 0.75m, 1.4m, and 2.05m above the floor, supply air and exhaust air respectively, using the step down method. Ch1, ch2, ch3 and ch4 correspond to No.11, No.10, No.9 and No.8 respectively. The positions were used as the representative points to examine temperature, concentration and local mean age of air in Figures 3 to 10. After the concentration was almost constant, the tracer gas injection was stopped, and the temperatures and concentrations of the measurement points shown in Figure 1 were measured for about one hour. In the Fig.2. Moving speed modes meantime the ambient temperature outside of the test Local air exchange index ε defined by the following room had been kept constant by an air conditioner. equation was used to evaluate the ventilation Figures 4 shows the vertical air temperature effectiveness as follows: distribution normalized by the supply air temperature near the object, which moved at speeds from 0.0 to 0.8m/ s, perpendicular to the perpendicular to the supply air 72 JAABE vol.3 no.1 May. 2004 Hiroshi Matsumoto Table 1. Measurement conditions Fig.3. Carbon dioxide concentration vs. Elapsed time Fig.4. Vertical air temperature distribution is shown in Figure 5. The vertical temperature difference was about 5 deg C when the speed was 0.4m/s. However for the case of the moving speed 0.8m/s, the temperature difference was only about 1 deg C. As the moving object speed was increased, the thermal stratification was gradually broken, and the room air temperature distribution became uniform. Figure 6 shows the distribution of the local mean age of air obtained from Equation 2 by the tracer decay method for the case of the object’s speeds 0.0 to 0.8m/s. For the case of 0.0m/s, i.e. standing still, the distribution of the local mean age of air was about 7 minutes. When the speed was 0.2m/s, the local mean age of air was almost same as the standing still case in the occupied zone, but the age increased at about 10 minutes in the Fig.5. Air temperature distribution vs. object moving speed upper zone of the room. For speeds over 0.6m/s the local mean age of air became larger than in the standing still flow. The temperature distributions for the case of speed case in all the zones. 0.4m/s was larger than that for the case of standing still, Figure 7 shows the vertical distribution of the local and the temperature distribution was small for the case air change index, defined by Equation 1, near the object, of 0.8m/s. measurement points 8 to 11, moving perpendicular to The air temperature distribution at the different height the supply air flow. The local air change index while above the floor for the cases of the different speeds, 0.0 standing still was about 340% in the occupied zone and to 0.8m/s, moving perpendicular to the supply air flow 290% in the upper zone. For speeds over 0.6m/s the local JAABE vol.3 no.1 May. 2004 Hiroshi Matsumoto 73 Fig.6. Distribution of local mean age of air Fig.7. Vertical distribution of local air change index air change index was about 200% in all the zones. These indices were larger than 100% for the ideal perfect mixing case. These results might have been caused by the horizontal distribution of the local mean age of air near the object. The local air change index in the occupied zone for all the cases, except for moving speed 0.2m/s, was less than in the case of the standing still case, as shown in Figure 7. Figure 8 shows the local air change index vs. the model moving speed. The local air change index in the occupied zone, 0.1 to 0.75m above floor level, was about 350% when the object’s speed was lower than 0.2m/s. The highest index was obtained for the moving speed 0.2m/ s. But no such peak was noticed in the upper zone, 1.4 to 2.05m above floor level. As confirmed by Mattsson (1999), the best ventilation efficiency was attained at the moving speed 0.1-0.3m/s, Fig.8. Local air exchange index vs. model moving speed but the mechanism has not been clearly resolved so far. He suggested that the current caused by the moving object might be spread horizontally at the different levels in the room, instead of being convected to the upper zone where it contributes to the recirculation process. He also inferred that the mechanism cleaned up the air in the poorly ventilated zones when there was no human activity in a room, and parts of the free convection current along the moving object were swept away from the body. Nevertheless, more detailed experiments such as the flow visualization and CFD approach will likely be required to resolve the mechanism. 3.2 Movement parallel to the supply air flow Figure 9 shows the air temperature distribution when the object moved along the supply air flow. The difference between the air temperature and the supply air temperature was increased as the model’s moving speed was increased. Figure 10 shows the local air change index profiles. Fig.9. Temperature distribution The more the speed increased, the smaller the distribution of the local air change index became. 74 JAABE vol.3 no.1 May. 2004 Hiroshi Matsumoto Fig.10. Local air change index vs. model moving speed Fig.11. Air change efficiency vs. moving object speed 3.3 Air change efficiency Acknowledgement Finally the air change efficiency, defined by Equation This study was supported in part by the 21st Century 3, vs. the object’s speed while moving perpendicularly, COE Program “Ecological Engineering for Homeostatic were investigated as shown in Figure 11. The air Human Activities”, from the Ministry of Education, efficiencies for both standing still and 0.2m/s were about Culture, Sports, Science and Technology. I am grateful 60% and around 50% for the case of speeds over 0.4m/ to Dr. Mattson, Prof. Sandberg and Prof. Stymne of the s. The room air distribution for the latter case can be Royal Institute of Technology, for giving me valuable considered nearly perfect mixing. advice concerning this study. 4. Conclusions References 1) Sandberg, M. and Mattsson, M. (1992) The Effect of Moving Heat The effect of a moving object on the performance Sources upon the Stratification in Rooms Ventilated by evaluation of displacement ventilation was investigated rd Displacement Ventilation, Proc. of the 3 International Conference by means of an experiment, using a movable heated on Air Distribution in Rooms, Vol.2. human model designed to go back and forth on a straight 2) Mattsson, M. and Sandberg, M. (1996) Velocity Field Created by th line using an electrical slider and motion controller, in a Moving Objects in Rooms, Proc. of the 5 International Conference on Air Distribution in Rooms, 547-554 full scale room model. According to the results, the more 3) Bjorn, E., Mattsson, M., Sandberg, M. and Nielsen, V. (1997) the moving speed increased, the smaller the temperature Displacement Ventilation - Effects of Movement and Exhalation, distribution and the local air exchange index in the Proc. of Healthy Buildings, 163-168 occupied zone became in all the moving directions. When 4) Mattsson, M., Bjorn, E., Sandberg, M., and Nielsen, P.V. (1997) the speed of the human model was set to 1.0m/s, the Simulating People Moving in Displacement Ventilated Rooms, Proc. of Healthy Buildings, 495-500 local air exchange index in the occupied zone was 20 to 5) Nguyen, L.H. and Matsumoto, H. (2001) CFD Analysis of Indoor 80% less than when it was standing still. The most Air Distribution in Consideration with a Moving Person, Proc. of significant effect on the air temperature distribution and rd the 3 Chubu Branch Meeting of SHASE, 65-68 (in Japanese) ventilation effectiveness was shown the object moved 6) Nguyen, L.H., Ohba, Y and Matsumoto, H. (2002) Study on Indoor Air Distribution affected by Moving Objects in Ventilated Rooms, perpendicular to the supply air flow. nd Proc. of the 2 Chubu Branch Meeting of SHASE, 45-48 (in It is difficult to compare the difference in air Japanese) distribution and ventilation performance caused by both 7) H. Matsumoto, L.H. Nguyen and Ohba Y. (2002) Influence of perpendicular and parallel movement. The air Moving Object on Air Distribution in Ventilated Rooms, Proc. of th distribution and ventilation efficiency were significantly the 8 International Conference on Room Air Distribution, 261- affected by both of the moving modes. The general 8) Mattsson. M. (1999) On the Efficiency of Displacement Ventilation tendencies of distributions of vertical air temperature, with Particular Reference to the Influence of Human Physical age of air, local mean age of air and the air change Activity, Dr. Thesis of KTH efficiency for the different moving speeds were all obtained from these experiments. JAABE vol.3 no.1 May. 2004 Hiroshi Matsumoto 75 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Asian Architecture and Building Engineering Taylor & Francis

The Influence of a Moving Object on Air Distribution in Displacement Ventilated Rooms

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Publisher
Taylor & Francis
Copyright
© 2018 Architectural Institute of Japan
ISSN
1347-2852
eISSN
1346-7581
DOI
10.3130/jaabe.3.71
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Abstract

As is well known, a moving person affects the stratification of indoor air and enhances the mixing in ventilated rooms with a displacement ventilation system. This paper describes the effect of moving object on the performance evaluation of displacement ventilation, by means of an experiment using a movable heated human model in a full scale room model. Distributions of air temperature and tracer gas concentration were measured to investigate the effect of the moving object’s direction, mode and speed on distribution of air in the room, and ventilation effectiveness. As a result of experiment, the moving object mode and speed showed a significant effect on the air temperature distribution and ventilation effectiveness. Keywords: displacement ventilation; moving object; full-scale experiment 1. Introduction breathing on the vertical contaminant distribution, and To keep thermal stratification is one of the most on the personal exposure of occupants (Bjorn et. al, important factors in controlling and maintaining good 1997). air qualityand high efficiency ventilation performance The above studies are not necessarily enough to in displacement ventilated rooms. However, physical resolve the mechanism and ventilation effectiveness of activity, like a moving person in the actual room has displacement ventilation as affected by human activity. been found to influence the stratification of indoor air Therefore the objective of this paper is to obtain and the performance of the ventilation system. This paper fundamental data by experimentation to clarify the describes the effect of a moving object on the mechanism of displacement ventilation in conjunction performance evaluation of displacement, through an with a moving object such as human activity in rooms. experiment using a movable heated human model, In this study the measurements were carried out using a designed to go back and forth on a straight line by means movable heated object controlled by an electrical slider of an electrical slider and a motion controller in a full and a motion controller in a full scale room model scale room model. Distributions of air temperature and (Nguyen et. al, 2002, Matsumoto et. al, 2002). The tracer gas concentration were measured to investigate distributions of air temperature, velocity and tracer gas the effect of the object’s direction of movement, mode concentration were measured for conventional systems and speed on the room air distribution and ventilation and displacement ventilation. The retest similar to the effectiveness. experiment done by Mattsson (1996, 1997) itself is seen Physical activity in a displacement ventilated room to be of value to the resolution of the moving object’s has been found to influence the performance of the effect. The originality of this study can be considered as ventilation system (Mattsson & Sandberg, 1994). The to investigate the influence of the object’s moving measurements of these studies were performed in a full direction and to develop an control system of an object scale test room, with a person simulator of cylindrical movement accurately to be compared with the results shape as the moving object (Mattsson et. al, 1996) and by the computational fluid dynamics (CFD) simulation also thermal mannequins (Mattson et. al, 1997). (Nguyen and Matsumoto, 2001). Furthermore full scale experiments were made in a displacement ventilated room with breathing thermal 2. Experimental Methods mannequins to study the effects of movements and A full scale room modelwith the dimensions 2.67x2.67x2.15m was used, along with a moving *Contact Author: Hiroshi Matsumoto, Toyohashi University of cylindrical object made of paper which was 1.2m high Technology, 1-1 Hibariga-oka, Tempakucho, Toyohashi 441-8580, and had a diameter of 0.3m. The room has a diffuser Japan with the dimensions, 0.3m high and 0.5m wide and an Tel: +81-532-44-6838 Fax: +81-532-44-6831 outlet, a hole with a diameter of 0.1m, located at 0.2m e-mail: matsu@tutrp.tut.ac.jp below the ceiling. The measurement points for (Received November 10, 2003 ; accepted April 6, 2004) temperature and concentration are shown in Figure 1. Journal of Asian Architecture and Building Engineering/May 2004/75 71 (1) (2) where τ is the nominal time constant, τ is the local mean s p age of air, C(t) is the normalized concentration, i.e. the actual value minus the supply air concentration, in time t, and C(0) is the normalized initial concentration The air change efficiency, ε , which evaluates the ventilation efficiency in a room, is defined by the following equations. Fig.1. Measurement system (3) The room was set up inside the laboratory of the Natural Energy Building, at the Toyohashi University of Technology, and was constructed with panels composed of 9mm plywood and 30mm insulation material on three sides and one side wall was made of 5mm acrylic glass. (4) The room was ventilated by a displacement ventilation system, and the moving object was designed to go back and forth on a straight line by a programmable controller and driver. The object was heated to simulate the heat where Ce(t) is the concentration of the exhaust air at flux of a human body, using a 100-watt bulb inside. time t, and <τ>is the room mean age of air. The temperature and tracer gas concentration, carbon The conditions measured here are shown in Table 1. dioxide, were measured by C-C thermo couples and a Two types of object movement were considered to multi gas monitor (B&K) respectively, to investigate the investigate the effect of different moving speeds on the temperature field and the ventilation effectiveness. The air distribution: perpendicular to the supply air flow and speeds of the object used were 0.0, i.e. standing still, along the supply air flow. The supply air flow rates for 0.4, 0.6, 0.8 and 1.0m/s. The moving modes were the former set of experiments (cases 1 to 5) were 35.7 controlled at a constant rate of acceleration or and 40m /h, and those for the latter set (cases 6 to 8) deceleration for the short time before and after the were 212.4 to 237.6m /h. The Archimedes numbers of stationary points and the constant speed in the middle the two sets were about 120 and 3 respectively. The as shown in Figure 2. supply air temperature was set to be 18 to 20 deg C during the experiments. 3. Measurement Results 3.1 Movement perpendicular to the supply air flow Figure 3 shows the measured carbon dioxide tracer gas concentration trends for the points ch1 to ch6 at 0.1m, 0.75m, 1.4m, and 2.05m above the floor, supply air and exhaust air respectively, using the step down method. Ch1, ch2, ch3 and ch4 correspond to No.11, No.10, No.9 and No.8 respectively. The positions were used as the representative points to examine temperature, concentration and local mean age of air in Figures 3 to 10. After the concentration was almost constant, the tracer gas injection was stopped, and the temperatures and concentrations of the measurement points shown in Figure 1 were measured for about one hour. In the Fig.2. Moving speed modes meantime the ambient temperature outside of the test Local air exchange index ε defined by the following room had been kept constant by an air conditioner. equation was used to evaluate the ventilation Figures 4 shows the vertical air temperature effectiveness as follows: distribution normalized by the supply air temperature near the object, which moved at speeds from 0.0 to 0.8m/ s, perpendicular to the perpendicular to the supply air 72 JAABE vol.3 no.1 May. 2004 Hiroshi Matsumoto Table 1. Measurement conditions Fig.3. Carbon dioxide concentration vs. Elapsed time Fig.4. Vertical air temperature distribution is shown in Figure 5. The vertical temperature difference was about 5 deg C when the speed was 0.4m/s. However for the case of the moving speed 0.8m/s, the temperature difference was only about 1 deg C. As the moving object speed was increased, the thermal stratification was gradually broken, and the room air temperature distribution became uniform. Figure 6 shows the distribution of the local mean age of air obtained from Equation 2 by the tracer decay method for the case of the object’s speeds 0.0 to 0.8m/s. For the case of 0.0m/s, i.e. standing still, the distribution of the local mean age of air was about 7 minutes. When the speed was 0.2m/s, the local mean age of air was almost same as the standing still case in the occupied zone, but the age increased at about 10 minutes in the Fig.5. Air temperature distribution vs. object moving speed upper zone of the room. For speeds over 0.6m/s the local mean age of air became larger than in the standing still flow. The temperature distributions for the case of speed case in all the zones. 0.4m/s was larger than that for the case of standing still, Figure 7 shows the vertical distribution of the local and the temperature distribution was small for the case air change index, defined by Equation 1, near the object, of 0.8m/s. measurement points 8 to 11, moving perpendicular to The air temperature distribution at the different height the supply air flow. The local air change index while above the floor for the cases of the different speeds, 0.0 standing still was about 340% in the occupied zone and to 0.8m/s, moving perpendicular to the supply air flow 290% in the upper zone. For speeds over 0.6m/s the local JAABE vol.3 no.1 May. 2004 Hiroshi Matsumoto 73 Fig.6. Distribution of local mean age of air Fig.7. Vertical distribution of local air change index air change index was about 200% in all the zones. These indices were larger than 100% for the ideal perfect mixing case. These results might have been caused by the horizontal distribution of the local mean age of air near the object. The local air change index in the occupied zone for all the cases, except for moving speed 0.2m/s, was less than in the case of the standing still case, as shown in Figure 7. Figure 8 shows the local air change index vs. the model moving speed. The local air change index in the occupied zone, 0.1 to 0.75m above floor level, was about 350% when the object’s speed was lower than 0.2m/s. The highest index was obtained for the moving speed 0.2m/ s. But no such peak was noticed in the upper zone, 1.4 to 2.05m above floor level. As confirmed by Mattsson (1999), the best ventilation efficiency was attained at the moving speed 0.1-0.3m/s, Fig.8. Local air exchange index vs. model moving speed but the mechanism has not been clearly resolved so far. He suggested that the current caused by the moving object might be spread horizontally at the different levels in the room, instead of being convected to the upper zone where it contributes to the recirculation process. He also inferred that the mechanism cleaned up the air in the poorly ventilated zones when there was no human activity in a room, and parts of the free convection current along the moving object were swept away from the body. Nevertheless, more detailed experiments such as the flow visualization and CFD approach will likely be required to resolve the mechanism. 3.2 Movement parallel to the supply air flow Figure 9 shows the air temperature distribution when the object moved along the supply air flow. The difference between the air temperature and the supply air temperature was increased as the model’s moving speed was increased. Figure 10 shows the local air change index profiles. Fig.9. Temperature distribution The more the speed increased, the smaller the distribution of the local air change index became. 74 JAABE vol.3 no.1 May. 2004 Hiroshi Matsumoto Fig.10. Local air change index vs. model moving speed Fig.11. Air change efficiency vs. moving object speed 3.3 Air change efficiency Acknowledgement Finally the air change efficiency, defined by Equation This study was supported in part by the 21st Century 3, vs. the object’s speed while moving perpendicularly, COE Program “Ecological Engineering for Homeostatic were investigated as shown in Figure 11. The air Human Activities”, from the Ministry of Education, efficiencies for both standing still and 0.2m/s were about Culture, Sports, Science and Technology. I am grateful 60% and around 50% for the case of speeds over 0.4m/ to Dr. Mattson, Prof. Sandberg and Prof. Stymne of the s. The room air distribution for the latter case can be Royal Institute of Technology, for giving me valuable considered nearly perfect mixing. advice concerning this study. 4. Conclusions References 1) Sandberg, M. and Mattsson, M. (1992) The Effect of Moving Heat The effect of a moving object on the performance Sources upon the Stratification in Rooms Ventilated by evaluation of displacement ventilation was investigated rd Displacement Ventilation, Proc. of the 3 International Conference by means of an experiment, using a movable heated on Air Distribution in Rooms, Vol.2. human model designed to go back and forth on a straight 2) Mattsson, M. and Sandberg, M. (1996) Velocity Field Created by th line using an electrical slider and motion controller, in a Moving Objects in Rooms, Proc. of the 5 International Conference on Air Distribution in Rooms, 547-554 full scale room model. According to the results, the more 3) Bjorn, E., Mattsson, M., Sandberg, M. and Nielsen, V. (1997) the moving speed increased, the smaller the temperature Displacement Ventilation - Effects of Movement and Exhalation, distribution and the local air exchange index in the Proc. of Healthy Buildings, 163-168 occupied zone became in all the moving directions. When 4) Mattsson, M., Bjorn, E., Sandberg, M., and Nielsen, P.V. (1997) the speed of the human model was set to 1.0m/s, the Simulating People Moving in Displacement Ventilated Rooms, Proc. of Healthy Buildings, 495-500 local air exchange index in the occupied zone was 20 to 5) Nguyen, L.H. and Matsumoto, H. (2001) CFD Analysis of Indoor 80% less than when it was standing still. The most Air Distribution in Consideration with a Moving Person, Proc. of significant effect on the air temperature distribution and rd the 3 Chubu Branch Meeting of SHASE, 65-68 (in Japanese) ventilation effectiveness was shown the object moved 6) Nguyen, L.H., Ohba, Y and Matsumoto, H. (2002) Study on Indoor Air Distribution affected by Moving Objects in Ventilated Rooms, perpendicular to the supply air flow. nd Proc. of the 2 Chubu Branch Meeting of SHASE, 45-48 (in It is difficult to compare the difference in air Japanese) distribution and ventilation performance caused by both 7) H. Matsumoto, L.H. Nguyen and Ohba Y. (2002) Influence of perpendicular and parallel movement. The air Moving Object on Air Distribution in Ventilated Rooms, Proc. of th distribution and ventilation efficiency were significantly the 8 International Conference on Room Air Distribution, 261- affected by both of the moving modes. The general 8) Mattsson. M. (1999) On the Efficiency of Displacement Ventilation tendencies of distributions of vertical air temperature, with Particular Reference to the Influence of Human Physical age of air, local mean age of air and the air change Activity, Dr. Thesis of KTH efficiency for the different moving speeds were all obtained from these experiments. JAABE vol.3 no.1 May. 2004 Hiroshi Matsumoto 75

Journal

Journal of Asian Architecture and Building Engineering – Taylor & Francis

Published: May 1, 2004

Keywords: displacement ventilation; moving object; full-scale experiment

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