The Indoor Microclimate of Prefabricated Buildings for Housing: Interaction of Environmental and Construction Measures

The Quality of ETICS in the Context of Energy and Social Changes (Case Study)

The paper focuses on the quality of external composite ETICS (External Technical Insulation Composite System) façade systems from a long-term perspective in the context of energy and social changes and subsequent paths of housing construction, including reconstructions and renovations of prefabricated housing developments. These changes follow mainly from the EU energy concept and strategy in relation to housing and have an impact potential well beyond 2030. The aim of the paper is to show, based on field research and laboratory diagnostics on a selected reference sample of housing affected by biodegradation, to what extent the quality of ETICS façades is affected by technological aspects during the application of ETICS exterior plasters and during the implementation of photocatalytic coatings. The investigation shows that the influence of the human factor is one of the main aspects of negative impacts.

Building Envelope and the Outdoor Microclimate Variable of Vernacular Houses: Analysis on the Environmental Elements in Tropical Coastal and Mountain Areas of Indonesia

Temperature and humidity are essential factors in analyzing a building’s thermal performance. This research presents the differences in field measurements of vernacular houses in coastal and mountain areas in Indonesia. Field measurements were taken for five consecutive days in four vernacular houses. The variables were measured at the beginning and at the peak of the rainy season. Analysis included a combination of graphic and descriptive methods. The research results show that the location difference between coast and mountain results in a relatively high difference in temperature (43.6%). The outdoor temperature in the mountain area is lower than that of the coastal area. The outdoor humidity of the mountain area is 0.69% higher than that of the coastal area. In the tropical coastal area, the outdoor temperature of the exposed-brick house is 0.94% lower than that of the coastal wooden house. The outdoor air humidity of the brick house is 0.89% higher than that of the coastal wooden house. In the tropical mountain area, the outdoor temperature of the exposed-stone house is 2.47% lower than that of the wooden house. The outdoor air humidity of the stone house is 0.4% lower than that of the wooden house. The outdoor conditions affect the indoor conditions of the respective houses. These microclimatic differences are influenced by micro-environmental factors, such as the density of surrounding buildings, amount of vegetation, and shading. The research shows that height difference is the most dominant factor influencing outdoor microclimate. Regional microclimate becomes the basis for determining the most suitable envelope materials in different areas. The innovative contribution of the work is, among other benefits, the identification of factors that influence the wellbeing of the buildings’ users in the researched geographical area and the analysis of the interaction of the external and internal environment of buildings. From the above facts, it follows that the results of this work can contribute to the development of prediction models to determine the type of cover, material, shape, and load-bearing elements needed to create comfortable and energy-efficient buildings.

Assessment of Indoor Air Quality in Residential Buildings of New England through Actual Data

Several studies on indoor air quality (IAQ) and sick building syndromes have been completed over the last decade, especially in cold countries. Efforts to make homes airtight to improve energy efficiency have created buildings with low ventilation rates, resulting in the build-up of indoor pollutants to harmful levels that would be otherwise unacceptable outdoors. This paper analyzed the infiltration rates, indoor temperatures, and variations in CO2, 2.5 μm particulate matter (PM2.5), and total volatile organic compound (TVOC) concentrations over the fall of 2021 in several homes in New England, USA. A relationship between outdoor and indoor conditions and ventilation strategies has been set using the results from blower door tests and actual indoor air quality data. Although all case studies lacked mechanical ventilation devices, such as those required by ASHRAE Standard 62.2, natural ventilation and air leakage have been enough to keep VOCs and PM2.5 concentration levels at acceptable values most of the studied time. However, results revealed that 25% of a specific timeframe, the occupants have been exposed to concentration levels of CO2 above 1000 parts per million (ppm), which are considered potentially hazardous conditions.

Benefit Evaluation Model of Prefabricated Buildings in Seasonally Frozen Regions

In order to effectively develop the benefit evaluation model of prefabricated houses in seasonal frozen soil areas, and improve the comprehensive benefits of prefabricated buildings, this paper proposes a life cycle benefit evaluation model for prefabricated buildings in seasonally frozen regions. According to the climatic characteristics of the area, the impact of the seasonally frozen regions is listed as an evaluation index in the construction stage for comprehensive analysis. The 16 indicators that affect the comprehensive benefits of prefabricated buildings are grouped by the nearest neighbor element analysis method. Fuzzy cluster analysis and analytic hierarchy process are used to filter out the most influential index group to calculate the index weight. Then the model proposed in this paper is compared with the existing model to test the validity of the model. The research results show that research and development costs weight is 0.23, design cost weight is 0.10, construction cost weight is 0.22, resource consumption weight is 0.25, building demolition cost weight is 0.04, and seasonal freezing effect weight is 0.16. The calculation result passed the consistency test and the expert scoring result conformed to the normal distribution, which proved the accuracy of the conclusion. It is proposed that the calculation result of the comprehensive benefit score of the model is 1.8% lower than the previous results, which proves the validity of the model. The model can speed up the efficiency of comprehensive benefit evaluation of prefabricated buildings thereby improving the development level of prefabricated buildings.