Individualised climate in future buildings. Fact or fiction? Mateja - PowerPoint PPT Presentation

Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Ljubljana, Slovenia Tokyo City University, Laboratory of Building Environment, Yokohama, Japan Individualised climate in future buildings. Fact or fiction? Mateja Dovjak * ,Masanori Shukuya, Aleš Krainer * Corresponding email: mdovjak@fgg.uni-lj.si Vienna, 9-11 September 2013

Problem ate in future buildings Users Environmental Individualised climat factors factors Specific activities Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Problem ate in future buildings • Current HVAC systems are not designed on the requirements of individual users � dissatisfaction, ↓ productivity, ↑ energy use for H/C purposes (Pheasant 1991). • Selkowitz, Lawrence Berkeley Lab: energy costs presents $21.53 per m2 per year, and people cost about $23174.67 per m2 (Peyton 1999). about $23174.67 per m2 (Peyton 1999). Individualised climate • Even a small improvement in productivity and reduction in absenteeism are more worthy than any energy savings. Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Purpose ate in future buildings • To design + test a user–centred H/C system that enables to create optimal conditions for individual user + minimal possible energy use for H/C of residential buildings . • Flexibility of the system was proven on specific users of the space as well as for various activities. Individualised climate • The system was compared with a reference conventional system. Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Methods System design ate in future buildings • The user–centred system was designed with upgraded methodology of engineering design (Asimow 1962; Dovjak, 2012). Individualised climat Figure 1. System design.

Methods Methods System design ate in future buildings • The basis for the design: vital physiological processes in human body that require a dynamic constancy or balance. • 3 essential components of all homeostatic control mechanisms : detector, integrator and effector. Individualised climat Figure 2. Basic elements of homeostatic control mechanism (Bresjanac & Rupnik 1999).

Al Faisaliah Tower 2, Methods The user–centred system Riyadh,SaudiaArabia e in future buildings • It is installed into a test active space, UL FGG; it includes 6 radiative panels connected with ICSIE system. Individualised climate i Figure 3. Basic architecture of the ICSIE system

Al Faisaliah Tower 2, ate in future buildings Methodology The user–centred system Riyadh,SaudiaArabia • It enables the control of indoor air temperature, CO 2 and illuminance under the influence of outdoor environment and users` requests. • The basic elements of the ICSIE system = elements of homeostatic control mechanism: sensor network system (detector), regulation system (integrator) and actuator system (effector). (integrator) and actuator system (effector). Individualised clima Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Al Faisaliah Tower 2, Methodology Users’ characteristics ate in future buildings Riyadh,SaudiaArabia • 3 virtual residential users were simulated for the analysis of individual thermal comfort conditions. • The user– centred system was tested regarding simulation of individual thermal comfort conditions and measured energy use. • The efficiency of the user–centred system was compared with conventional system (oil-filled Individualised climat electric heaters and split system with indoor A/C unit). electric heaters and split system with indoor A/C unit). Table 1. Users’ characteristics and specific activities Metabolic rate Effective clothing User/activity [met] insulation [clo] Grandfather, 1.0 0.7 watching TV Teenager, weight- 6.0 0.2 training Mother, Yoga 1.2 0.7

Methodology te in future buildings • In the simulation users were exposed to experimental conditions based on in–situ real–time measurements . In the case of conventional system T ai =T mr = T o ; in the case of user– • centred system T ai ≠ T mr ≠ T o differed. • User–centred system enabled to set up different combinations of T ai and T mr and T o that resulted in optimal human body exergy balance for every individual separately. Individualised climate Table 3. Real-time experimental conditions for the simulation of individual thermal comfort conditions System User T ai [° C] T mr [° C] v [m/s] RH in [%] All 21 21 0.1 40 Conventional 22 24 0.1 Grandfather 40 User–centred 17 19 0.1 40 Teenager 22 24 0.1 40 Mother

Al Faisaliah Tower 2, Methods Human body exergy calculations Riyadh,SaudiaArabia ate in future buildings • For the analysis of individual thermal comfort conditions, exergy concept was introduced. • Exergy analysis jointly treats processes inside the human body and processes in built environment . • Human body exergy balance model developed by Shukuya et al. (2010), upgraded into spreadsheet software for the calculation of hbEXCr (Iwamatsu and software for the calculation of hbEXCr (Iwamatsu and Individualised climate Asada, 2009). [ ] [ ] [ ] [ ] − = + Exergy input Exergy consumptio n Exergy stored Exergy output Cool/warm rad. Exhalation, Breath air Exg sweat consumption Warm rad. Warm conv. Cool/warm conv. from inner part

Al Faisaliah Tower 2, Methods Human body exergy calculations Riyadh,SaudiaArabia ate in future buildings • To maintain comfort conditions , it is important that the exergy consumption and stored exergy are at optimal values with a rational combination of exergy input and output. • Individual thermal comfort conditions were analysed by human body exergy balance , calculated human by human body exergy balance , calculated human Individualised climate body exergy consumption rates and PMV index with spread sheet software developed by Hideo Asada (Shukuya et al. 2010). • For exergy calculations, the reference environmental temperature (the outdoor environmental temperature, Tao) and RHout = Tai and RHin. Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Al Faisaliah Tower 2, Conventional system Results Riyadh,SaudiaArabia ate in future buildings Individualised climate Figure 4. Human body exergy balances for three virtual users of active space equipped with conventional system.

Al Faisaliah Tower 2, User-centred system Results Riyadh,SaudiaArabia ate in future buildings Individualised climate Figure 5. Human body exergy balances for three virtual users of active space equipped with user–centred system.

Al Faisaliah Tower 2, User-centred system Results Riyadh,SaudiaArabia ate in future buildings te in future buildings • Approximately the same conditions were selected for the Tai variate among systems ± 0.5 K; 0.8% assumed error). systems’ comparison (equal set-point T, time period, Tao and • The measured energy use for space heating was by 11% lower when using user–centred system compared to the conventional system. The energy use for space cooling was by 73% lower for user–centred system. Table 4. Results of energy use (C cool , C heat ) for selected conditions. Table 4. Results of energy use (C cool , C heat ) for selected conditions. Individualised climate Individualised climate System T range User–centred Conventional Reduction [° C] [%] Heating 11 23–24 T ai =23.3 ° C T ai = 23.7° C winter T ao = -2.60° C T ao = -2.60° C C heat = C heat = 2.630 MJ 2.950 MJ T ai =24.83° C T ai = 24.30° C 73 Cooling 24–25 summer T ao =19.45° C T ao = 19.88 ° C C cool = C cool = 1.116 MJ 4.068 MJ

Conclusions ate in future buildings • The main role of user–centred system is to create optimal conditions for various users and activities . These would result in an optimal human body exergy balance . • To maintain thermal comfort for all users and activities, it is important that exergy consumption and stored exergy are at optimal values with rational combination of exergy inputs and outputs. Individualised climat • • The presented analysis was carried out for three selected The presented analysis was carried out for three selected subjects with different demands and needs for thermal comfort. However, user–centred system is a flexible system . • It is possible to create optimal microclimatic conditions for every individual user and activities. • The system could be applied in residential or public buildings. Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Ljubljana, Slovenia ACKNOWLEDGMENTS Research program Building Construction and Building Physics, UL FGG founded by the Ministry of Higher Education, Science and Technology, Republic of Slovenia, Education, Science and Technology, Republic of Slovenia, COST action C24 Analysis and design of innovative systems with LowEx for application in build environment, CosteXergy, TIGR Sustainable And Innovative Construction P13.1.1.2.03.0003, 3211-10-000465.