Page 25 - InnoRenew CoE International Conference 2021, Healthy and Sustainable Renovation with Renewable Materials
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mperature-based approach for assessing buildings in terms of providing
thermal comfort for occupants
Sabina Jordan 1, Jože Hafner 2
1. Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, sabina.jordan@zag.si
2. Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, joze.hafner@zag.si
Buildings have been essential to human existence for centuries, as they are intended for physical and
psychological protection. It is also known that they can have a significant impact on the user, as people in
modern societies spend 80 to 90 percent of their time indoors. Therefore, the quality of buildings is very
important for their well-being, comfort and health. In addition to the influences due to personal responses
of the users, the basic principles of their thermal comfort affected by age, gender, clothing, activity, or even
cultural habits are mostly related to environmental factors. Among them, the temperatures play a key role
in ensuring a balance between produced and emitted body heat. In order to achieve thermal comfort
in buildings, in addition to appropriate humidity and air velocity, it is necessary to pay attention to the
adequate air temperatures and the radiant temperatures of surrounding surfaces. When planning thermal
comfort, temperature comfort can be assessed in a variety of ways. One of them is based on a calculated
estimate of the percentage of time in which indoor operating temperatures exceed the temperature
limit for user comfort. The presented research is based on the analysis of simulated temperatures of a
modelled living room in a lightweight residential building with an extremely high proportion of glazing.
The results showed that without mechanical cooling, there is a pronounced daily summer overheating,
regardless of the intense shading of the glazed surfaces. The analyses of the calculations also showed
that due to the relatively small thermal accumulation capacity of the lightweight structure and large
windows, the surface temperatures have a relatively small influence on the operating temperature. At the
monthly level, the calculated average operating temperature differs from the average air temperature by
a maximum of 0.2K Thus, in this case, the air temperature can be taken into account when estimating the
time when the temperature exceeds the limit of user temperature comfort, especially when observing
on annual level. In addition, the results at selected values for thermal comfort limit temperatures (24, 25,
26 and 28°C) showed extremely large differences in the calculated annual assessment of the overheating
rate. Therefore, the choice of the appropriate thermal comfort limit temperature is crucial.
Keywords: thermal comfort, building assessment, overheating, operative temperature, numerical
simulations
Acknowledgement
First Author gratefully acknowledges receiving funding from the LIFE IP CARE4CLIMATE project, which is
an integrated project co-financed by the European LIFE programme, The Climate Change Fund and the
project partners program name (LIFE17 IPC/SI/000007).
HEALTHY AND SUSTAINABLE RENOVATION WITH RENEWABLE MATERIALS
25
thermal comfort for occupants
Sabina Jordan 1, Jože Hafner 2
1. Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, sabina.jordan@zag.si
2. Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, joze.hafner@zag.si
Buildings have been essential to human existence for centuries, as they are intended for physical and
psychological protection. It is also known that they can have a significant impact on the user, as people in
modern societies spend 80 to 90 percent of their time indoors. Therefore, the quality of buildings is very
important for their well-being, comfort and health. In addition to the influences due to personal responses
of the users, the basic principles of their thermal comfort affected by age, gender, clothing, activity, or even
cultural habits are mostly related to environmental factors. Among them, the temperatures play a key role
in ensuring a balance between produced and emitted body heat. In order to achieve thermal comfort
in buildings, in addition to appropriate humidity and air velocity, it is necessary to pay attention to the
adequate air temperatures and the radiant temperatures of surrounding surfaces. When planning thermal
comfort, temperature comfort can be assessed in a variety of ways. One of them is based on a calculated
estimate of the percentage of time in which indoor operating temperatures exceed the temperature
limit for user comfort. The presented research is based on the analysis of simulated temperatures of a
modelled living room in a lightweight residential building with an extremely high proportion of glazing.
The results showed that without mechanical cooling, there is a pronounced daily summer overheating,
regardless of the intense shading of the glazed surfaces. The analyses of the calculations also showed
that due to the relatively small thermal accumulation capacity of the lightweight structure and large
windows, the surface temperatures have a relatively small influence on the operating temperature. At the
monthly level, the calculated average operating temperature differs from the average air temperature by
a maximum of 0.2K Thus, in this case, the air temperature can be taken into account when estimating the
time when the temperature exceeds the limit of user temperature comfort, especially when observing
on annual level. In addition, the results at selected values for thermal comfort limit temperatures (24, 25,
26 and 28°C) showed extremely large differences in the calculated annual assessment of the overheating
rate. Therefore, the choice of the appropriate thermal comfort limit temperature is crucial.
Keywords: thermal comfort, building assessment, overheating, operative temperature, numerical
simulations
Acknowledgement
First Author gratefully acknowledges receiving funding from the LIFE IP CARE4CLIMATE project, which is
an integrated project co-financed by the European LIFE programme, The Climate Change Fund and the
project partners program name (LIFE17 IPC/SI/000007).
HEALTHY AND SUSTAINABLE RENOVATION WITH RENEWABLE MATERIALS
25
