Abstract: A tool to aid literature reviews by powerful full-text analysis of multiple documents (PDF and TXT files). It also automatically generates BibTex references (from web services) which you can export as a .bib file.
Permalink: https://doi.org/10.5281/zenodo.10370540

Abstract: Tool to design embedded electric or hydronic heating/cooling in floors, walls or ceilings. Calculates both thermal comfort and energy-efficiency peformance. Can be used for low-exergy systems.

Abstract: Simulation of nearly net-zero GHG-emission neighbourhoods, with distributed hydronic heating & cooling, and building-integrated PV electricity generation.

Abstract: A Microsoft Excel macro with state-of-the art multi-parameter optimization algorithms that outperform the Excel Solver AddIn when the solution domain contains multiple local minima, discontinuous gradient, or regions with constant cost (no gradient).

Abstract: An important contribution of human exposure to particles occurs indoors, since people spend a major part of their days indoors, at home, at work or at school. However, there is little knowledge on particle characteristics and sources indoors. Our study focuses on submicron particles formed under real-life conditions in a primary school. Particle size distributions (in the range 10 – 400 nm) were measured in a classroom as part of a project to optimise air quality and the use of energy for ventilation. The school was built recently and opened in autumn 2016. It is equipped with low emitting interior and a demand controlled ventilation system. The measurements were carried out continuously (1 minute time resolution) for 3 weeks in May/June 2018 while the classroom was in normal use. A full class had 24 pupils aged 9-10 years and 1- 2 teachers. Also measurements of volatile organic compounds, O₃, NO₂, CO₂ and ventilation rates in the room were available. Different ventilation strategies were tested during the field campaign. Particle formation and growth was observed frequently and could often be related to changes of the ventilation rate. The formation of ultrafine indoor particles occurs through reactions between ozone and volatile organic compounds emitted by occupants themselves, paints, building products and by furniture. Activities, such as peeling an orange in the presence of ozone, may also result in new particle formation. The first particle formation event of the day was generally observed in the mornings after the ventilation was turned on and ozone from outdoors was brought into the classroom where it reacted with VOCs from indoor sources. The events usually lasted for 2 hours and were often still ongoing when the pupils entered the class room at 08:30. In the afternoon, after the ventilation was turned off, the ozone present in the room was consumed by VOCs. There were also particle formation events during the school day, presumably caused by the presence of occupants and their activities. We will present the contributions from different VOCs to the formation of secondary organic aerosol and identify the main sources leading to particle formation in the classroom.

Abstract not available

Abstract not available

Abstract not available

Abstract not available

Abstract: The aim of this study is to investigate whether children’s bioeffluent generation rate is proportional to their carbon dioxide (CO₂) generation rate. Consequently, to assess if there is a need to differentiate the CO₂-setpoint for different user groups, focusing on children. Perceived air quality (PAQ) and odour intensity (OI) were assessed in three classrooms in Oslo, Norway. Two second-grade classes (7-8 years old) were compared with one eighth-grade class (13-14 years old). An untrained test panel consisting of 16 people visited each classroom twice and were asked to evaluate PAQ and OI upon entering the classrooms. The CO₂ levels in the classrooms were kept constant at either 600 ppm or 1100 ppm during each visitation. The results showed that average PAQ-score was significantly worse in the second-grade classrooms compared to the eighth-grade classroom. For perceived odour intensity, the average score indicated that the odour was stronger in the second-grade classrooms compared to the eighth-grade classroom, however, this difference in score was not significant. Our results indicate a need for differentiation of setpoints for CO₂-DCV based on user groups, especially for children.
Permalink: https://doi.org/10.1088/1757-899X/609/4/042062

Abstract: The aim of this paper is to assess whether reducing the minimum ventilation airflow rate (Vmin) has any negative impacts on perceived air quality (PAQ) upon entering an unoccupied room. Seventeen healthy young adults were asked to assess PAQ in 18 unoccupied classrooms upon entry. Extra pollution sources were introduced in two classrooms, while three other classrooms were not cleaned. The ventilation rate in each classroom was set in a random order to off, low (0.9/1.1 l/s per m2), medium (1.3 l/s per m2) and high (2.0 l/s per m2). Increasing the ventilation rate resulted in a significant improvement of the PAQ-score, with highest PAQ-score when Vmin is set to high and lowest when the ventilation is off. However, most of this increase occurred when increasing ventilation to the low rate. Classrooms that were not cleaned for two days of normal use prior to the test only showed a marked reduced PAQ at all ventilation rates.
Permalink: https://doi.org/10.1088/1757-899X/609/4/042038

Abstract: Energy efficiency in buildings is nowadays considered as an essential step to reduce CO₂ emissions and energy utilization. At the same time, new technologies such as building space heating using active air heating has simplified the heating system without any need for backup heating system. This study investigated the thermal stratification of mixing ventilation system equipped with a radial active supply diffuser for space heating of an office room designed according to the Norwegian passive house standard by using Star-CCM+. Simulations were performed for different supply airflow rates with corresponding slot openings of the active diffuser at different outdoor conditions for winter season. The combined effect of the supply airflow rate and the outdoor air temperature were also described in the form of Archimedes number (Ar). The results showed that adopting active diffuser could avoid the temperature stratification for all the simulated cases by preserving the throw length of supply jet. In addition, the lowest temperature effectiveness of 38% occurred when a high supply temperature was used in the coldest day. Furthermore, with the supply temperature 24 °C, the airflow rate 49.4 l/s at the outdoor temperature -15 °C would result in a favorable average of PMV ⁓ 0.497.
Permalink: https://doi.org/10.1051/e3sconf/201911104033