Thermal comfort -the state of mind, which expresses satisfaction with the thermal environment- is an important aspect of the building design process as modern man spends most of the day indoors. This paper reviews the developments in indoor thermal comfort research and practice since the second half of the 1990s, and groups these developments around two main themes; (i) thermal comfort models and standards, and (ii) advances in computerization. Within the first theme, the PMV-model (Predicted Mean Vote), created by Fanger in the late 1960s is discussed in the light of the emergence of models of adaptive thermal comfort. The adaptive models are based on adaptive opportunities of occupants and are related to options of personal control of the indoor climate and psychology and performance. Both models have been considered in the latest round of thermal comfort standard revisions. The second theme focuses on the ever increasing role played by computerization in thermal comfort research and practice, including sophisticated multi-segmental modeling and building performance simulation, transient thermal conditions and interactions, thermal manikins.
Thermal comfort in operating theatres is a less addressed research component of the in-door environment in operating theatres. The air quality naturally gets most attention when considering the risk of surgical site infections. However, the importance of thermal comfort must not be underestimated. In this research, the current thermal comfort situation of staff members is investigated. Results show that the thermal comfort for the members of a surgical team is perceived as not optimal. Application of the PMV and DR models needs further attention when applied for operating theatres. For the investigated ventilation systems, the differences in thermal comfort outcomes are small.
In indoor comfort research, thermal comfort of care-professionals in hospital environment is a little explored topic. To address this gap, a mixed methods study, with the nursing staff in hospital wards acting as participants,was undertaken. Responses were collected during three weeks in the summer (n = 89), and four weeks in the autumn (n = 43). Analysis of the subjective feedback from nurses and the measured indoor thermal conditions revealed that the existent thermal conditions (varying between 20 and 25 °C) caused a slightly warm thermal sensation on the ASHRAE seven point scale. This led to a slightly unacceptable thermal comfort and a slightly obstructed self-appraised work performance. The results also indicated that the optimal thermal sensation for the nurses—suiting their thermal comfort requirements and work performance—would be closer to‘slightly cool’than neutral. Using a design approach of dividing the hospital ward into separate thermal zones, with different set-points for respectively patient and care-professionals’comfort, would seem to be the ideal solution that contributes positively to the work environment and, at the same time, creates avenues for energy conservation.
Living walls are increasingly becoming tools for green climate adaptation in the urban context, but distribution efforts are dampened by high investment and operational costs. Those costs are derived mainly from designing and manufacturing unique equipment for such new projects. A system using wastewater could relieve some of these costs by decreasing their irrigation and fertigation needs. Muuras is developing helophyte filters integrated into living wall systems that can readily be attached to any wall surface, with the ultimate purpose of local water recycling. Additionally, based on the fact that Muuras is a pre-engineered company, their product is modular, which means that a considerable advantage is recognized regarding the decreased capital cost. To realize scalable implementation of such a system, research with regards to the purification capabilities of lightweight substrates and small wetland plant species is imperative. In SoW & FloW, the NHL Stenden Water Technology Professorship proposes a collaboration between two SME’s (Muuras, Greenwave Systems) and a company (DeSaH), to evaluate a selection of substrates and endemic plant species based on their capability to use domestic wastewater as an irrigation source.
Epoxy thermosets are extensively used as coatings, adhesives and in structural applications as they typically impart outstanding mechanical and electrical properties as well as chemical resistance. The currently used epoxy thermosets are produced from fossil-based non-recyclable materials. To be able to meet the circularity and sustainability goals set by the EU, this needs to change. Biobased epoxy thermosets from residual streams are considered a promising and urgently needed alternative to regular epoxy thermosets. The Cashew Nut industry could play a significant role in the development of these biobased epoxy thermosets. Global cashew nut production is about 4 million tons/year. The cashew nutshell is currently discarded as waste or used as an inefficient fuel, creating environmental issues. The cashew nutshell contains Cashew Nutshell Liquid (CNSL), which consists of the valuable chemical component cardanol. Cardanol can be used to produce biobased epoxy thermosets with balanced rigid-flexible performance. However, systematic studies about the production, properties, recyclability and commercial opportunities of the cardanol based epoxy thermosets are lacking. In this project consortium partners Avans, RUAS, Maastricht University, TU/e, Nuts2, Charcotec, NPSP, SABA, and Prokol jointly aim to answer the question: How can we develop sustainable and economically viable biobased epoxy thermosets and composites from cashew nutshell residue? First the pyrolysis process will be optimized for the effective production of CNSL. Next, the cardanol in the CNSL will be purified and modified to make the recyclable biobased epoxy thermoset. Finally, by adding biocarbon (which is also produced during the pyrolysis of cashew nutshell) to the biobased epoxy thermoset, a composite with enhanced mechanical, electrical, and thermal properties is expected to be obtained. The success of this project serves as a catalyst for the development of sustainable solutions in the thermoset industry and contribute to a sustainable application of cashew nut residue.
