Numerical Two-Dimensional Steady-State Evaluation of the Thermal Transmittance Reduction in Hollow Blocks

Abstract

After the first concerns about global energy consumption around the 70 s, some standards were established with the aim of improving the energy efficiency in buildings. In this context, according to the US Department of Energy, heating, ventilation, and air conditioning (HVAC) systems comprise about 50% of the building energy consumption and 20% of total consumption in the United States. Energy consumption of this kind of equipment depends on several factors, one of the most important factors being the heat transfer through the building envelope. In the walls, hollow concrete blocks have become common in recent years due to advantages such as their strength, their space for pipes and wiring, and fast construction, among others. In order to reduce the thermal load, several forms of insulation were tested on these constructive elements. Thus, effects of the low emissivity, insulating material, radiant shields, and baffles on the inner cavities of the blocks are presented in this paper. Effects of temperature differences between the exterior surfaces on the thermal transmittance and on the combined average heat transfer coefficient inside the cavities are also shown.

Thermal Performance Assessment of External Wall Construction for Energy-Efficient Buildings

“…With the current 3D numerical model methodology, assumptions and dimensions, it is not possible to find matching results to compare with. Therefore, 2D simulations were performed at different differential temperatures to compare the results of thermal conductance with the results obtained from reference (Fogiatto et al, 2019). Similar physical domain and boundary conditions were carefully set up for comparison.…”

“…The annual potential savings was found to be 46.1 $/m 2 corresponding to 7.9 cm insulation thickness when actual electricity tariff was considered. Fogiatto et al (2019) studied thermal transmittance reduction in hollow blocks using numerical two dimensional steady state analysis. Five scenarios were tested including; standard configuration without any form of insulation, low emissivity coating on the inner surfaces, cavities filled with insulating material, radiant shields in the middle of cavities, and baffles in the inner surfaces, respectively.…”

“…Figure 2. Comparison of numerical model results of thermal transmittance with reference(Fogiatto et al, 2019) …”

Experimental test for mechanical properties of new tenon composite wall using thermal self-insulation block

“…With climate change and energy conservation becoming serious concerns, the architectural concepts of ''ecological cities,'' 'green buildings, ''building energy conservation,'' and ''low-carbon buildings'' are gradually gaining attention (Diao et al, 2017;Raut and Gomez, 2018;Vasconcelos et al, 2013). Statistical data indicate that the heating, ventilation, and air conditioning systems for buildings comprise approximately 50% of the building energy consumption and 20% of the total energy consumption in the United States (Fogiatto et al, 2019;Vı´ctor et al, 2018). Within the service age of buildings, heat loss through external protection or structure components accounts for 70%-80% of the total heat loss (Diao et al, 2018), while that through external walls accounts for approximately 25% and 35% of the total heat loss during winter and summer, respectively (Laaouatni et al, 2019;Wati et al, 2017).…”

Development and Performance Test including Mechanical and Thermal of New Tenon Composite Block Masonry Walls

“…As a result, architectural concepts of "ecological cities," "green buildings," "building energy conservation," and "low-carbon buildings" have been gradually applied [1][2][3]. Statistical data indicate that heating, ventilation, and air-conditioning systems for buildings comprise approximately 50% of the building energy consumption and 20% of the total energy consumption in the United States [4,5]. Table 1 shows the energy consumption percentage of different building parts, including the airconditioning, illumination, kitchen, and water supply systems, and it can be seen that air-conditioning accounts for most of the energy consumption, which is related to the air temperature and the thermal performance of external maintenance components in a building.…”