Methods to Assess the Thermal Properties of the Building Envelope

2020 ◽  
pp. 13-30
Author(s):  
David Bienvenido-Huertas ◽  
Carlos Rubio-Bellido
Keyword(s):  
Thermal Properties ◽  
Building Envelope

scholarly journals Determination of Optimum Envelope of Religious Buildings in Terms of Thermal Comfort and Energy Consumption: Mosque Cases

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6597
Author(s):  
Ahmet Bircan Atmaca ◽  
Gülay Zorer Gedik ◽  
Andreas Wagner
Keyword(s):  
Thermal Properties ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Thermal Insulation ◽  
Energy Savings ◽  
Gain Factor ◽  
Building Envelope ◽  
Comfort Level ◽  
Humid Climate ◽  
Savings Rate

Mosques are quite different from other building types in terms of occupant type and usage schedule. For this reason, they should be evaluated differently from other building types in terms of thermal comfort and energy consumption. It is difficult and probably not even necessary to create homogeneous thermal comfort in mosques’ entire usage area, which has large volumes and various areas for different activities. Nevertheless, energy consumption should be at a minimum level. In order to ensure that mosques are minimally affected by outdoor climatic changes, the improvement of the properties of the building envelope should have the highest priority. These optimal properties of the building envelope have to be in line with thermal comfort in mosques. The proposed method will be a guide for designers and occupants in the design process of new mosques or the use of existing mosques. The effect of the thermal properties of the building envelope on energy consumption was investigated to ensure optimum energy consumption together with an acceptable thermal comfort level. For this purpose, a parametric simulation study of the mosques was conducted by varying optical and thermal properties of the building envelope for a temperature humid climate zone. The simulation results were analyzed and evaluated according to current standards, and an appropriate envelope was determined. The results show that thermal insulation improvements in the roof dome of buildings with a large volume contributed more to energy savings than in walls and foundations. The use of double or triple glazing in transparent areas is an issue that should be considered together with the solar energy gain factor. Additionally, an increasing thickness of thermal insulation in the building envelope contributed positively to energy savings. However, the energy savings rate decreased after a certain thickness. The proposed building envelope achieved a 33% energy savings compared to the base scenario.

EVALUATION OF SELECTED DYNAMIC MODELS IN COMPARISON WITH HOT BOX TEST RESULTS FOR MEASUREMENT OF BUILDING ENVELOPE THERMAL PROPERTIES

2020 ◽  
Vol 15 (2) ◽  
pp. 29-43
Author(s):  
Xinrui Lu ◽  
Ali M. Memari
Keyword(s):  
Thermal Properties ◽  
Temperature Difference ◽  
Energy Use ◽  
Dynamic Models ◽  
Network Models ◽  
Building Envelope ◽  
Energy Simulation ◽  
Average Model ◽  
Building Components ◽  
R Value

ABSTRACT This research is mainly focused on the experimental measurement of R-value by several different models. Building energy consumption accounts for about 40% of the total energy use in the U.S, and therefore accurate energy simulation is desired. The R-value is one of the key parameters that can influence the energy simulation results and therefore is of great importance. The Average Model has long been the most widely accepted method to measure the thermal properties of building components. However, its steady-state assumption and dependence on temperature difference limit its use especially for in-situ measurement. In this study, several dynamic models, including the Pentaur Model and R-C Network Models, are studied with test data obtained from a series of hot box tests performed in the Building Enclosure Testing Laboratory. The results show that the 3R2C model has the best performance and a desirable stability of accuracy with respect to different levels of temperature difference, and therefore is recommended for practical measurement. The results also indicate that unlike the Average Model, the accuracy of dynamic models does not necessarily depend on the level of temperature difference.

Mechanical and Thermal Properties of PCM Wallboards Based on Gypsum and Paraffin

2011 ◽  
Vol 71-78 ◽  
pp. 3553-3557
Author(s):  
Xiao Peng Wang ◽  
Zhen Qiu Shen ◽  
Yi Zhang ◽  
Dong Xu Li
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Energy Consumption ◽  
Building Energy ◽  
Building Envelope ◽  
Mechanical And Thermal Properties ◽  
Building Energy Consumption

This paper studied on preparation, mechanical and thermal properties of two PCM wallboards made of gypsum and paraffin composite, PCM particles wallboard and PCM bag packed wallboard. Density, flexural and compressive strength and thermal conductivity of PCM particles wallboards deceased as PCM particles dosage increasing. Only PCM particles wallboard with PCM particles dosage 30% is suitable. Thermal comparison between PCM wallboards and pure gypsum wallboard shows that two PCM wallboards have better thermal properties and PCM wallboards can be used in building envelope to cut down building energy-consumption.

Is stochastic grey-box modelling suited for physical properties estimation of building components from on-site measurements?

2017 ◽  
Vol 40 (5) ◽  
pp. 444-471 ◽  
Author(s):  
An-Heleen Deconinck ◽  
Staf Roels
Keyword(s):  
Thermal Properties ◽  
Thermal Performance ◽  
Profile Likelihood ◽  
Dynamic Parameter ◽  
Building Envelope ◽  
Estimation Methods ◽  
Energy Models ◽  
Dynamic Parameter Estimation ◽  
Building Components ◽  
Parameter Estimation Methods

In current energy requirements, the thermal performance of buildings is assessed with simplified energy models. A performance label is calculated based on thermal properties of the constituent components of the building envelope. These properties, however, do not include factors such as workmanship issues, or moisture or airflow influences which might affect the thermal performance as designed. To have a better view on the actual thermal quality of building components, a reliable thermal characterisation method of building components on-site is required. The typically used semi-stationary measurement methods have an application that is seasonally bounded or can require long measurement periods. Because of these drawbacks, dynamic parameter estimation methods have gained interest. In this article, the physical interpretability of a typical stochastic grey-box model used to thermally characterise building components is assessed. The identifiability of this model structure is examined by observing the profile likelihood of its parameters for typical measurements. The results allow identification of the extent to which models can estimate the thermal properties of building components in a robust way. A comparison of both analyses allows to define indications for physically interpretable parameters.

Usage of Hydrophilic Mineral Wool Panels in Green Roof Systems in Passive Houses

2014 ◽  
Vol 1041 ◽  
pp. 75-78 ◽  
Author(s):  
Petr Vacek ◽  
Libor Matějka
Keyword(s):  
Thermal Properties ◽  
Thermal Insulation ◽  
Water Saturation ◽  
Green Roof ◽  
Mineral Wool ◽  
Building Envelope ◽  
Horizontal Drainage ◽  
Water Accumulation ◽  
Passive Houses

Hydrophilic panels can be used in extensive vegetation green roof systems as a soil replacement. They are lightweight (also with full water saturation), have certified thermal insulation properties in wet conditions and beyond all, they have laboratory approval of vertical and horizontal drainage ability, similar as a special drainage nep composites.Low weight of panels is further more advantageous in the intensive green roof systems and passive houses– static demands on roof and wall constructions can be dramatically decreased. Special water-accumulation panels can be used in retention roofs. Multiple-layered panels can help with thermal properties of building envelope of passive houses.

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