Exhaled air temperature as a function of ambient temperature in flying and resting ducks

Exhaled air temperature (T exh) has a paramount effect on respiratory water loss during flight. For migratory birds, low T exh potentially reduces water loss and increases flight range. However, only three studies provide empirical data on T exh during flight. The aim of this study was to record T exh of birds during rest and flight at a range of controlled ambient temperatures (T amb). One wigeon and two teal flew a total of 20 times in a wind tunnel at T amb ranging from 1° to 24°C. T exh during flight did not differ between the two species and was strongly correlated with T amb (T exh=1.036 T amb + 13.426; R²=0.58). In addition, body temperature had a weak positive effect on T exh. At a given T amb, T exh was about 5°C higher during flight than at rest.

Intra urban air temperature distributions in historic urban center

The study investigates the urban heat island effect in Malaysian historic town Malacca through seven mobile traverses, as carried out on 10 December 2011. It aims to identify the intra-urban air temperature differences between heritage core zone, new development area and outskirts of the city. Air temperature variations were also analyzed across three different zones; namely the outskirts, the heritage site and the city center district. Heat index values were then calculated based on air temperature and relative humidity to gauge the level of outdoor thermal comfort within the study area. Based on the indications, one may conclude that the heritage place’s core zone is currently threatened by escalating temperatures and that its current temperature range falls within the “caution” and “extreme caution” categories. Furthermore, no significant difference was observed between the peak temperatures of the old city quarters and newer areas; despite the disparities in their urban forms. Therefore, it is hoped that the study, with its implications, will be able to influence future environmental consideration in heritage city of Melaka.

Characterising indoor air temperature and humidity in Australian homes

Information about indoor air temperatures in residential buildings is of interest for a range of reasons, e.g. the health and comfort of occupants, energy demand for space heating and cooling. To date there have been few long term studies that measure and characterise indoor air temperatures in Australian homes. New primary research undertaken by the authors measured temperatures in 273 homes over the period 2011 to 2014 in seven climate zones, from Melbourne in the south to Cairns in the north of Australia. Humidity data was also collected in 20 homes. This paper is a description of the data collected and the subsequent analysis.

Indoor temperatures were compared with outdoor temperatures and a mathematical model was fitted to the data. In general, monthly average indoor temperatures were found to be 2 degreesC higher than monthly average outdoor temperatures, apart from periods with consistently cold weather, where the monthly average outdoor temperature was less than 20 degreesC, which were found to have larger differences. The indoor temperature model developed has been compared with data measured by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in 438 homes in three Australian cities. The model developed using project measurements are highly consistent with the CSIRO data.

Further data collection compared indoor and outdoor humidity in 20 houses in Sydney and Melbourne. The indoor humidity ratio was found to be, on average, slightly higher than outdoors, but indoor levels generally track outdoor levels quite closely. This is likely due to the high air exchange rate in most houses.

The effect of green roofs on pedestrian level air temperature

Man made alterations have resulted in higher air temperatures in cities, compared to their surrounding rural areas. There are many attempts to modify the urban design elements to ameliorate urban heat island effect. One among them is the concept of green roofs. There is a potential to incorporate vegetation to the large roof area of the buildings. Several studies investigated the effect of micro and macro scale implementation of green roofs. Most of these studies examined the impact of green roofs on the air temperature variation at the roof level, whereas studies are lacking on the effect of green roof at the pedestrian level. Therefore, this study aims to explore the impact of green roofs on the air temperature at pedestrian level, in the central business district (CBD), using Melbourne as a case study. A generic layout of Melbourne's CBD is modelled using ENVI-met 3.1 BETA 4. A number of different scenarios with different green roof coverages and building heights are examined. It was found that green roofs did not have significant impact on the temperatures at pedestrian level.

Temperature-dependent sex determination of Ascension Island green turtles

We examined the role played by temperature in the duration of incubation and sex ratio of green turtle hatchlings at Ascension Island, one of the most important green turtle rookeries in the Atlantic. Temperature at control sites at nest depth and in 39 green turtle nests was measured using small temperature recording devices. The sex ratio of hatchlings was ascertained in a sub-sample of monitored nests allowing the description of the relationship between intranest temperature and hatchling sex ratio, demonstrating a pivotal incubation temperature of 28.8°C. The seasonal profile in sex ratio of hatchlings produced on all nesting beaches at Ascension Island was estimated, showing that a female-biased sex ratio would be expected with a female:male ratio of the order of 3:1. The use of nest temperature, air temperature, sand temperature at control sites, and incubation duration as proxies to estimate hatchling sex ratio are discussed.

Effects of rising temperature on the viability of an important sea turtle rookery

A warming world poses challenges for species with temperature-dependent sex determination, including sea turtles, for which warmer incubation temperatures produce female hatchlings. We combined in situ sand temperature measurements with air temperature records since 1850 and predicted warming scenarios from the Intergovernmental Panel on Climate Change to derive 250-year time series of incubation temperatures, hatchling sex ratios, and operational sex ratios for one of the largest sea turtles rookeries globally (Cape Verde Islands, Atlantic). We estimate that light-coloured beaches currently produce 70.10% females whereas dark-coloured beaches produce 93.46% females. Despite increasingly female skewed sex ratios, entire feminization of this population is not imminent. Rising temperatures increase the number of breeding females and hence the natural rate of population growth. Predicting climate warming impacts across hatchlings, male-female breeding ratios and nesting numbers provides a holistic approach to assessing the conservation concerns for sea turtles in a warming world. © 2014 Macmillan Publishers Limited.

Perceived conditions of workers in different organizational settings

Purpose: – Research into office design and its effect on employee satisfaction and performance has attracted considerable contemporary research interest. However, most studies have tended to concentrate on the impact of the built environment on human performance, ignoring the actual needs of employees working in different organizational settings. This paper hence aims to investigate the nature and extent of occupant satisfaction with the built environment in different organizational settings in Australia for a range of climates.

Design/methodology/approach: – A survey was conducted in Australia from 2004-2005, comprising 41 buildings, including six government buildings, 14 educational buildings and 21 commercial buildings. The Kruskal-Wallis H test was used to explore whether there are differences in the mean ranking of office environment satisfaction amongst the three organizational settings, and the Mann-Whitney U test was employed to further test whether there are differences in the mean ranking of office environment satisfaction between any two groups.

Findings: – Significant differences were found in aspects of air, temperature, space suitability, flexibility, usability and controllability. Employees in commercial settings seem to be more satisfied with their physical work environment than employees in other organization types. Employees in educational settings showed the highest satisfaction with most variables in the workspace design and management category. Government employees showed a lower level of satisfaction with their physical work environment and workspace design and management.

Originality/value: – Moreover, the government and educational groups showed more similarity with each other, while the commercial group displayed significant difference.

Microclimatic modeling of the urban thermal environment of Singapore to mitigate urban heat island

This study investigates the urban heat island effect in Singapore and examines the key factors causing this effect. The possibilities of improving heat extraction rate by optimizing air flow in selected hot spots were explored. The effect of building geometry, façade materials and the location of air-conditioning condensers on the outdoor air temperature was explored using computational fluid dynamics (CFD) simulations. It was found that at very low wind speeds, the effect of façade materials and their colours was very significant and the temperature at the middle of a narrow canyon increased up to 2.5 °C with the façade material having lower albedo. It was also found that strategically placing a few high-rise towers will enhance the air flow inside the canyon thereby reducing the air temperature. Adopting an optimum H/W ratio for the canyons increased the velocity by up to 35% and reduced the corresponding temperature by up to 0.7 °C.

Building surfaces and their effect on the urban thermal environment

Use of high reflectance surfaces reduces the amount of solar radiation absorbed through building envelopes and urban structures and thus keeping their surfaces cooler. The cooling energy savings by using high reflectance surfaces have been well documented. Higher surface temperatures add to increasing the ambient temperature as convection intensity is higher. Such temperature increase has significant impacts on the air conditioning energy utilization in hot climates. This study makes use of numerical simulations to analyze the effect of commonly used building materials on the air temperature. A part of the existing CBD (Central Business District) area of Singapore was selected for the study. A series of Computational Fluid Dynamics (CFD) simulations have been carried out using the software CFX-5.6. It was found that at low wind speeds, the effect of materials on the air temperature was significant and the temperature at the middle of a narrow canyon increased up to 2.5[degrees]C with the facade material having lower reflectance.

Effect of materials on the urban thermal environment a CFD simulation approach

Use of high albedo materials reduces the amount of solar radiation absorbed through building envelops and urban structures and thus keeping their surfaces cooler. The cooling energy savings by using high albedo materials have been well documented. Higher surface temperatures add to increasing the ambient temperature as convection intensity is higher. Such temperature increase has significant impacts on the air conditioning energy utilization in hot climates. This study makes use of a parametric approach by varying the temperature of building facades to represent commonly used materials and hence analyzing its effect on the air temperature through a series of CFD (Computational Fluid Dynamics) simulations. A part of the existing CBD (Central Business District) area of Singapore was selected for the study. Series of CFD simulations have been carried out using the software CFX-5.6. Wind tunnel experiments were also conducted for validation. It was found that at low wind speeds, the effect of materials on the air temperature was significant and the temperature at the middle of a narrow canyon increased up to 2.52°C with the façade material having lowest albedo.

Simultaneous presentation of measured and calculated environmental results

Continuous measurement of internal and external environmental parameters is critical to our understanding of how buildings perform. Yet, the quantity and variety of time-series data can be quite overwhelming as well as onerous to decipher and present. In addition to this, is the fact that several of the collected data are useless in their raw format unless processed through algorithms to obtain identifiable and meaningful results.
These circumstances challenge the conventional way we present accumulated data and their processed outputs in order to get a better understanding of how and why the environmental performance occurred. It would be ideal if all of the collected and processed data could be presented in a simultaneous, yet, useful format. It is exactly the intention of this paper to suggest and present such a process as well as its format.
An example case study is provided where several parameters (air velocity, mean radiant temperature, humidity and air temperature) are measured periodically to calculate a time-series of internal comfort performance. However, external conditions of solar radiation and solar position as well as air temperature drive the interior building surface temperatures and help to explain the end result of internal comfort.
A program has been written to present the various sets of data graphically, in an integrated manner, animated as a function of time. The animation shows solar position, a cursor scanning weather data, the changing infra-red image and a representation of the resulting internal comfort performance throughout the
monitored period.

Effect of gender on thermal comfort in multicultural public places

The city and the urban environment became extremely important in the daily lives of the increasing number of urban populations across the world. Urban research acknowledges that planning urban places should be responsive to the diversity of population. The aim of this paper is to analyse the results of thermal comfort study in the outdoor urban places. The location has been monitored regarding standard comfort variables: air temperature, humidity, wind speed, and globe temperature. The quantitative assessment of comfort conditions was combined with a questionnaire of pedestrians’ thermal comfort perception. In this paper, the analysis of observed thermal sensation with regard to gender and cultural background concerning the sensitivity of different groups to heat and cold is presented.

Measurement and solutions to thermal comfort, CO2 and ventilation rates in schools

An Australian research facility, conducted a study on several different school classrooms in regards to their thermal comfort, CO2 levels, air temperature stratification and ventilation rates in a selection of Victorian (Melbourne, Australia) schools during a winter season. A brief literature review reveals similar IAQ problems elsewhere (outside Australia) and suggests several HVAC concepts that provide potential solutions. Our intention is to highlight particular IAQ discrepancies in existing school classroom design resulting from these case study measurements, suggesting construction and mechanical operational conditioning improvements.In particular this research confirms the urgency and necessity of addressing IAQ problems in schools, world wide. Our results of the Australian school classroom measurements are similar to other parts of the world, indicating that CO2 levels, ventilation rates and air temperatures are non-compliant with the standards.