Influence of building typology on Indoor humidity regulation

This article presents a case study to explain the influence of building typologies in regulating indoor humidity, thereby impacting Indoor Environment Quality. Results from Vernacular (adobe) and conventional (brick/concrete) building typologies in the composite climate zone of India have been presented

Discerning relative humidity trends in vernacular and conventional building typologies for occupant health

The indoor built environment has a significant impact on the occupant's physiological, psychological, and behavioral health. Moisture is an important parameter that has a direct bearing on the quality of a built environment. Commonly referred to as water, moisture impacts nearly all dimensions of a building's functional performance, i.e., structural, durability, thermal, acoustics, indoor air quality, ventilation/freshness/odor, aesthetics, and also influences the health of occupants. Very high humidity can cause physical and chemical deterioration of materials, increased action of biological contaminants, and accelerate the spread of infections. However, low humidity can result in breathing difficulties, cough, irritation in the eye, wheeze, skin chapping, etc. Building materials have an impact on indoor air quality. Vernacular building materials are often effective in regulating the thermal performance of a building, ensuring energy efficiency. Also, people residing in such dwellings have been found to have high resilience to withstand the adverse external conditions. This exploratory study aims to understand the performance of building materials for the regulation of indoor moisture and air quality for promoting the health and well-being of the building and the occupants. The study involves monitoring a conventional (brick, concrete) dwelling and vernacular dwellings (adobe construction, brick/lime construction) situated in India's Composite Climatic zone. The result suggests that dwelling constructed with earth (adobe) maintains the narrowest range of variation in indoor relative humidity. The indoor relative humidity variation range is widest in cement concrete construction. The paper examines factors that regulate relative humidity in the indoor environment. Understanding the moisture buffering capacity of the building materials in indoor RH regulation for occupant health has also been discussed.publishedVersio

Comparison of moisture buffering properties of plasters in full scale simulations and laboratory testing

The regulation of indoor relative humidity is a key factor for the provision of occupant health and comfort. Passive humidity regulation is possible if porous materials, for example clay and gypsum plasters, are exposed to the indoor environment. Materials that are highly hygroscopic can help regulate relative humidity levels through their capacity to adsorb and release water vapour from and to the indoor air via a dynamic process referred to as moisture buffering. Laboratory test methods have been developed to measure this moisture buffering capacity, which are well-suited for comparative testing of relatively small material samples under controlled conditions. However, quantification of the impact of hygroscopic materials in real buildings requires additional evaluation, like field testing and the support of simulation models, which can successively be used for the development of new protocols capable of giving information about materials’ moisture buffering performances indoors. This paper investigates moisture buffering capacity of three hygroscopic plasters (clay, gypsum and lime), and compares measurements obtained in the laboratory to those from numerical simulations of a single-zone room space. The dynamic sorption capacity of the plasters was investigated using the NORDTEST protocol and results compared to those from hygrothermal simulation. Differences are identified between the two methods in the quantification of the moisture buffering potential, which lead to further investigation on the effect of ventilation and moisture transport through the entire wall assembly. The significance of this paper is to show building moisture regulation involves also different factors, such as ventilation and walls moisture transport, which will impact the moisturebuffering potentials indoors. Consequently, it is necessary to better understand moisture buffering in real buildings, to quantify the influence of hygroscopic materials indoors, and introduce alternative laboratory testing, to give quantitative information about their impact in buildings.<br/

Adaptation of buildings to climate change: an overview

Buildings worldwide have evolved based on local resources and skills, evolving form and orientation to ensure a productive and comfortable indoor environment. Traditional habitations rely on passive climate-responsive mechanisms and physiological resilience. At the same time, contemporary buildings rely increasingly on active mechanisms for fine-tuned convenience and comfort. Those buildings are becoming less habitable due to climate change. This paper presents an overview of research into climate-responsive building adaptation, identifying various factors determining a building’s ability to regulate external climatic conditions in providing a habitable indoor environment. The review covers the ability of occupants to manage their thermal environment and adaptation mechanisms, including various adaptation strategies attributed to climate change. Besides a review of relevant research tools and methodologies, the paper also identifies future research challenges. Those challenges include but are not limited to evaluating climate classification provided by building standards given climate change, the need for region-specific climate-change vulnerability assessment of the built environment to develop specific adaptation strategies, a survey of vernacular structures to understand their inherent adaptation capacities, developing a framework to study building adaptation, etc. Thus, this review opens the possibility of further research in building adaptation

Evaluating effectiveness of non-water based cleaning mechanisms for PV systems

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.PV systems in tropical regions are gifted with ample sunshine, but also vulnerabilities to high cell temperatures and dust settlement. Dust related degradation is progressive and if left unattended, can severely inhibit by more than 40% the efficiency and output of the system. Current mechanisms of cleaning PV systems adopt large quantities of clean water, making the system unsustainable. The current study thereby investigates the effectiveness of non-water based cleaning mechanisms based on traditional palm-leaf brooms. These brooms were found to be more than 90% effective in comparison to water based cleaning. The reason for this effective cleaning has been further scrutinized based on micro-structure studies and dust adhering propertiesdc201

BIPV: a real-time building performance study for a roof-integrated facility

Building integrated photovoltaic system (BIPV) is a photovoltaic (PV) integration that generates energy and serves as a building envelope. A building element (e.g. roof and wall) is based on its functional performance, which could include structure, durability, maintenance, weathering, thermal insulation, acoustics, and so on. The present paper discusses the suitability of PV as a building element in terms of thermal performance based on a case study of a 5.25 kWp roof-integrated BIPV system in tropical regions. Performance of PV has been compared with conventional construction materials and various scenarios have been simulated to understand the impact on occupant comfort levels. In the current case study, PV as a roofing material has been shown to cause significant thermal discomfort to the occupants. The study has been based on real-time data monitoring supported by computer-based building simulation model

Life Cycle Assessment (LCA) to Assess Energy Neutrality in Occupancy Sensors

Life Cycle Assessment (LCA) is a quantitative model which attempts to assess the aggregated environmental impacts of various life cycle stages of a product and helps in various sustainability support decisions for product design and development. This methodology has been standardized by ISO and been accepted by various organizations and designers. The present study focuses on Life Cycle Assessment (LCA) as a tool for Energy Neutrality Assessment with the help of a case study of occupancy sensors in net energy conservation assessed through life cycle energy study and simulation methods provided by LCA tools. Occupancy sensors aim to reduce energy consumption by switching off energy appliances when the monitored space has no occupants. Moreover, it is evident that though it saves some energy at the place of installation but these measures needs to be evaluated from Life-cycle energy framework to effectively understand the net energy conservation over the life cycle of such devices. This approach focuses on two dimensions of investigation, the former being the life-cycle energy involved in the adoption of such a device, while the later concentrates on the environmental aspects of various life cycle stages. In this case study, Occupancy Sensors have been studied for their adoption in typical office buildings. The study would compare the effectiveness of occupancy sensor in reducing net energy consumption computed over its life span with the aid of existing LCA Simulation tools and models. The results reported measures the effectiveness of such measures and devices in net energy conservation and its environmental impacts, accounting for the data uncertainty and limitations in data availability

Impact of dust on solar photovoltaic (PV) performance: Research status, challenges and recommendations

The peaking of most oil reserves and impending climate change are critically driving the adoption of solar photovoltaic's (PV) as a sustainable renewable and eco-friendly alternative. Ongoing material research has yet to find a breakthrough in significantly raising the conversion efficiency of commercial PV modules. The installation of PV systems for optimum yield is primarily dictated by its geographic location (latitude and available solar insolation) and installation design (tilt, orientation and altitude) to maximize solar exposure. However, once these parameters have been addressed appropriately, there are other depending factors that arise in determining the system performance (efficiency and output). Dust is the lesser acknowledged factor that significantly influences the performance of the PV installations. This paper provides an appraisal on the current status of research in studying the impact of dust on PV system performance and identifies challenges to further pertinent research. A framework to understand the various factors that govern the settling/assimilation of dust and likely mitigation measures have been discussed in this paper. (C) 2010 Elsevier Ltd. All rights reserved