PLEA

A ThermO-Drain (TOD) is a system that uses water cooled by night sky to drain the radiant heat within a building. In office buildings, ‘all air-cooled’ systems are most prevalent. The study aimed to assess the thermal comfort of occupants in a ground and two storied naturally ventilated office building in the composite climate of Nashik in India where TOD system was installed. Assessment was conducted by taking hourly readings over a 25-hour period in peak summer of May 2017. Primary data collected included Dry Bulb Temperature (DBT) and Relative Humidity (RH) indoors, surface temperature of top and bottom of roof slab and Globe temperature within the office. Secondary data for the same period was obtained from the Indian Meteorological Department (IMD). Monthly electricity bills were used to measure the Energy Performance Index (EPI). The Tropical Summer Index (TSI), an index suggested in the National Building Code (NBC) 2016 of India, was calculated. Results show that the indoor operative temperature in the peak of summer with outdoor temperature of 36.30C was found to be close to the neutral temperature of 27.50C. The EPI of 26.5 kwh/m2/year falls within the BEE 5-star rating of below 40 kwh/m2/year.

The multiple criterion scale developed by Hopkinson is extensively utilised to analyse the subjective degree of discomfort due to glare. Using a luminance adjustment procedure, the brightness of a glare source is adjusted to reveal four levels of discomfort, typically: just imperceptible, just acceptable, just uncomfortable, and just intolerable. In many experimental studies, observers are requested to attend to each level of discomfort in ascending order, from the lowest to the highest criterion. There are, however, reasons to believe that assessments made using adjustments might be affected by the initial anchor, i.e. the setting of the variable stimulus before an adjustment is made, and by order effects, this influencing the reported thresholds of discomfort. To investigate anchor bias and order effects, two Hopkinson-like multiple criterion adjustment experiments were performed, respectively with three different initial anchors and three order sequences (ascending, descending, and randomised). The results revealed substantive bias due to anchor and order effects, primarily at lower glare criteria. This demonstrates the need for caution when interpreting subjective evaluations of discomfort due to glare and estimating the robustness of glare indices derived from studies that used models fitted to data obtained with Hopkinson’s multiple criterion scale and luminance adjustment procedure.

There are now more than four million refugees living in camps around the world. The majority of such camps are within inhospitable environments, often with extreme climates. This paper focuses on the thermal conditions of shelters in the Azraq refugee camp (Jordan), subject to an arid climate with high temperatures during the hot season. Due to political and other sensitivities, whole-, or multi-year monitoring of occupied shelters—and hence the empirical determination of overheating—is difficult. Instead, internal conditions in the shelters were monitored for three weeks in summer and used to validate computer models of the accommodation. These models were then used to generate annual predictions of overheating assessed through overheating criteria based on thermal discomfort and physiological indicators of heat stress. Building on these results, the performance of alternative designs specifications or shelter operation strategies were investigated through parametric analysis. The results show maximum indoor temperatures over 45°C. Overheating thresholds were exceeded for more than 20% of the year and physiological indicators suggest the possibility of health-threatening conditions. The use of alternative designs and strategies reduced overheating to nearly 2% of the year, with a steep reduction of severe heat stress indicators.

The increasing complexity of modern architectural geometries emphasizes the need for more accurate simplified calculations of comfort analysis in architectural design. Such computations often require to solve complicated equations, among which the calculation of Mean Radiant Temperature (MRT) is notable. The goal of this paper is to propose a fast reliable technique, named Numerous Vectors (NV), to calculate MRT even in the presence of complex geometries. Considering the area, orientation, and distance of different radiant geometries, the process suggests an innovative method to find the view factor by projecting the surrounding surfaces on a unit sphere as the human body. Rather than separately computing the values of view factors for individual radiant surfaces, the method determines the proportion of the radiation from all surfaces by a single-step process. The NV method can also be used for the calculation of multiple parameters involved in MRT such as solar and atmospheric radiations. The proposed process is much faster than conventional methods available to calculate the view factors and the results are proved to be in a good agreement with analytical data.

Highly reflective and specular building envelopes have been widely adopted to help maximize energy performance of buildings and to achieve occupant thermal and visual comfort. This strategy has ensured these benefits inside the building envelope while making a significant and sometimes unintended impact outside the building envelope. Reflected sunlight from specular building envelopes can cause discomfort glare to people outside buildings. It is important to investigate exterior glare issues caused by specular material characteristics. This often parallels, but is distinct from, thermal issues resulting from radiant gain. Preliminary exterior glare scene documentations were performed in downtown Los Angeles to understand existing problems. Human subject study was performed in an outdoor research setting. High dynamic range (HDR) imaging was used to capture and evaluate different levels of scenes and to visualize glare sources in the field of view. Collected subjective evaluation data and captured glare scenes were statistically analyzed to prove the existence of exterior glare problems. Perceptible and disturbing glare levels were experienced by the subjects, and strong correlations were found between human visual discomfort and excessive sunlight reflections from specular building envelopes.

This paper tackles the environmental and social challenges that have emerged in the aftermath of the recent economic crisis. The acute recession that has dramatically struck Europe has had devastating consequences, not only for national economies but also for the population. In the Spanish case, its high dependence on an over stimulated construction sector led the country to a sudden recession. Defaults related to real state became commonplace and credit was halted. Without access to credit, most companies (including but not limited to real state) started to cease their activity. It had a double consequence: On the one hand, the number of evictions increased dramatically as households without regular income could not repay their mortgages. On the other hand, suburbs were filled with ‘ghost towns’ of unfinished buildings and empty states, which were abandoned by bankrupted developers.
The paper reports on a research that aims to provide a feasible housing alternative for crisis-affected families and young people who intend to emancipate in this harsh scenario. It is a short term plan based on the temporal colonization of unfinished buildings. The structures will be retrofitted with low cost and high performance solutions to create environmental quality within the boundaries of the existing frame. These interventions will also reactivate those deserted suburban enclaves where they have been erected thus protecting them from informal occupancy. Architectural solutions will qualify the urban environment while responding to urgent housing needs without compromising the legitimate rights of landowners.