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

Individualised climate in future buildings. Fact or fiction?

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

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 factors

Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia Individualised climat

factors Specific activities

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).

Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Individualised climate about $23174.67 per m2 (Peyton 1999).

• Even a small improvement in productivity and

reduction in absenteeism are more worthy than any energy savings.

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.

Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Individualised climate

• The system was compared with a reference

conventional system.

• The user–centred system was designed with upgraded

methodology of engineering design (Asimow 1962;

Dovjak, 2012).

System design Methods ate in future buildings

Figure 1. System design.

Individualised climat

• 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. Methods System design Methods ate in future buildings

Figure 2. Basic elements of homeostatic control mechanism (Bresjanac & Rupnik 1999).

Individualised climat

Al Faisaliah Tower 2, Riyadh,SaudiaArabia

• It is installed into a test active space, UL FGG; it includes 6

radiative panels connected with ICSIE system.

The user–centred system

Methods e in future buildings

Figure 3. Basic architecture of the ICSIE system

Individualised climate i

Al Faisaliah Tower 2, Riyadh,SaudiaArabia

The user–centred system

Methodology ate in future buildings

• It enables the control of indoor air temperature,

CO2 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).

Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Individualised clima (integrator) and actuator system (effector).

Al Faisaliah Tower 2, Riyadh,SaudiaArabia

Users’ characteristics

Methodology ate in future buildings

• 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 electric heaters and split system with indoor A/C unit). Individualised climat electric heaters and split system with indoor A/C unit).

User/activity

Metabolic rate [met] Effective clothing insulation [clo]

Grandfather, watching TV 1.0 0.7 Teenager, weight- training 6.0 0.2 Mother, Yoga 1.2 0.7

Table 1. Users’ characteristics and specific activities

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 Tai =Tmr = To; in the case of user–

centred system Tai ≠Tmr ≠ To differed.

• User–centred system enabled to set up different combinations of

Tai and Tmr and To that resulted in optimal human body exergy balance for every individual separately.

Individualised climate

System User Tai [° C] T mr [° C] v [m/s] RH in [%] Conventional All 21 21 0.1 40 User–centred Grandfather Teenager Mother 22 17 22 24 19 24 0.1 0.1 0.1 40 40 40

Table 3. Real-time experimental conditions for the simulation of individual thermal comfort conditions

Al Faisaliah Tower 2, Riyadh,SaudiaArabia

Human body exergy calculations

Methods 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 Individualised climate software for the calculation of hbEXCr (Iwamatsu and Asada, 2009).

Warm rad.

Breath air

Exg consumption Exhalation, sweat from inner part

Cool/warm rad. Cool/warm conv. Warm conv.

[ ] [ ]

n consumptio Exergy input Exergy −

[ ] [ ]

• utput

Exergy stored Exergy + =

Al Faisaliah Tower 2, Riyadh,SaudiaArabia

Human body exergy calculations

Methods ate in future buildings

• To maintain comfort conditions, it is important that

the exergy consumption and stored exergy are at

• ptimal values with a rational combination of exergy

input and output.

• Individual thermal comfort conditions were analysed

by human body exergy balance, calculated human

Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia

Individualised climate by human body exergy balance, calculated human 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.

Al Faisaliah Tower 2, Riyadh,SaudiaArabia

Results ate in future buildings Conventional system Individualised climate Figure 4. Human body exergy balances for three virtual users of active space equipped with conventional system.

Al Faisaliah Tower 2, Riyadh,SaudiaArabia

User-centred system Results ate in future buildings Individualised climate Figure 5. Human body exergy balances for three virtual users

• f

active space equipped with user–centred system.

Al Faisaliah Tower 2, Riyadh,SaudiaArabia

ate in future buildings

Table 4. Results of energy use (Ccool, Cheat) for selected conditions.

• Approximately the same conditions were selected for the

systems’ comparison (equal set-point T, time period, Tao and Tai variate among systems ±0.5 K; 0.8% assumed error).

• 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.

User-centred system Results te in future buildings Individualised climate

System Trange [° C] User–centred Conventional Reduction [%] Heating winter 23–24 T

ai=23.3 °

C T

ao= -2.60°

C Cheat= 2.630 MJ T

ai = 23.7°

C T

ao = -2.60°

C Cheat = 2.950 MJ 11 Cooling summer 24–25 T

ai=24.83°

C T

ao=19.45°

C Ccool = 1.116 MJ T

ai = 24.30°

C T

ao = 19.88 °

C Ccool = 4.068 MJ 73

Table 4. Results of energy use (Ccool, Cheat) for selected conditions.

Individualised climate

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

• ptimal values with rational combination of exergy inputs

and outputs.

• The presented analysis was carried out for three selected

Chair for Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia Individualised climat

• 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, 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.