Impact of climate change on thermal comfort and energy performance in offices - a parametric study

This paper investigates the impact of climate change on comfort and energy performance in offices in relation to the influence of building design and occupants. It focuses on a typical cellular office room in the context of Athens, Greece, as input for a parametric study using the building simulation software EnergyPlus. Three different building design variations are combined with two different occupant scenarios and 4 different weather data sets for IPCC climate change scenario A2.

For naturally ventilated buildings adaptive thermal comfort is evaluated according to ASHRAE Standard 55 and EN 15251. For mixed mode context evaluation is focused on greenhouse gas emissions and peak heating / cooling loads. Results indicate significant impact of the climate change on thermal comfort, and deviations between both comfort models. Comparing climate change, building design and occupant scenarios indicates that building design is the predominant influence on thermal comfort, whereas occupants are the predominant influence on greenhouse gas emissions.

Designing for thermal comfort near a glazed exterior wall

In many highly glazed buildings, the thermal comfort of the occupants will tend to be related to the incoming solar energy and the heat transfer behaviour of the glazing. In this study, several glazing systems were designed using the software tools VISION 3 (University of Waterloo 1992) and WINDOW-6 (Lawrence Berkeley National Laboratory 2011), with a view to improving thermal environment of occupants near the glazed wall of a commercial office. The systems were fabricated and experimentally tested to validate the software modelling results. Subsequently, the glazing systems were retro-fitted to the office and tested in situ for a summer month. Results of this testing, in the form of Fangers’ predicted mean vote (PMV) and the predicted percentage dissatisfied (PPD), are presented, and some options for improving the thermal environment in this near-façade zone are discussed.

"Tomorrow's car" : Deakin Universities new cross vehicle that combines the best of 2 worlds

Motorbike riders are 34-times more likely to die in a crash compared to car drivers per km travelled (1). Such safety risks together with special skill requirements for the driver and much lower comfort compared to normal cars are the main reasons why motorbikes represent only a fraction of all vehicle sales in developed countries. Deakin University is developing a revolutionary cross-over fun vehicle with ultra low fuel consumption and emissions. This new vehicle generation combines the best of two worlds: the fun to drive, low cost, and small size of a scooter together with the safety, comfort and easiness to operate of a car. The result is a vehicle that is more fuel efficient than most cars or even scooters.

Various tilting cross over vehicles have been presented over the last decade that were trying to automate the tilting control of narrow vehicles to make them safer. Examples of these concepts are the Carver, Clever and in some way also the MP3 scooter from Piaggio. The problem with fully enclosed concepts like the Carver or Clever is that they require very complex and therefore also expensive tilting control systems so that the vehicles are not price competitive compared to low cost micro cars or even normal small cars. The MP3 on the other hand comes with a tilting control system which is only semi automatic so that typical car advantages - comprehensive safety features like crush zones, roll over protection, air bags, safety belts or comfort features like full weather protection including heating and cooling – can not be provided.

Deakin’s approach is quite different to the above mentioned concepts. The requirements were derived based on two different investigations: The first step was a critical evaluation of social trends and the second step was an in-depth benchmarking study of existing concepts which identified the typical strengths and weaknesses of these concepts. In a critical next step a new concept was created that addresses most of the weaknesses of existing tilting three-wheelers in a holistic approach by setting clear priority rankings for the vehicle targets, based on current trends. The priorities were set in the following order: Safety, Affordability, Fun and Efficiency (SAFE).

The key feature that enables an enclosed tilting vehicle is a fully automatic tilting control system. With an automatic tilting control system the driver does not need to put the feet on the ground to balance the vehicle when he stops, so the vehicle can be built with a full enclosure. This allows the implementation of typical car like safety features (seat belts, roll over structure, crush zones, air bags). The SafeRide™ tilting control system is a passive system that involves the driver’s balancing sense in its feedback control system. The vehicle has typical scooter like steering characteristics, where the steering is initiated through countersteering. Another safety critical design feature is the crush zone between the two front wheels which is not possible with only one front wheel or with the powertrain positioned between the front wheels, as the powertrain can’t absorb a lot of energy due to its structural stiffness and density. The passive tilting control system is quite simple and therefore makes the vehicle very affordable, an important factor for successful commercialisation.

Another advantage of integrating the human balancing senses in the feedback control of the tilting system is that the system kicks in slightly after the human balancing reacts. In some instances that can generate the typical adrenalin thrill known from riding a bike. This fun factor is quite common with many trend sports like mountain biking, surfing, roller-skating, snowboarding, or skateboarding. Some of these sports have seen very rapid growth only a short time after they have been invented. Utilising the human balancing system during driving also makes the vehicle safer as the adrenalin is produced after reaching a semi-stable driving condition that is controlled by the vehicles tilting control system, but before the vehicle reaches an unstable driving condition that can not be controlled by the vehicle but only (eventually) by the driver – if he has got the required driving skill and if he is alert enough.

Efficiency superior to most cars and scooters is achieved by the aerodynamics of a fully enclosed body structure in combination with the small frontal area of a typical scooter and the droplet shape enabled by the relatively wide front with 2 wheels and the very narrow tail with only one rear wheel. The passive tilting system also contributes to the extreme efficiency as the system only draws some small electrical power for the electronic control unit. Another feature is a low cost exhaust energy recovery system which is discussed in another paper.

Compact stacked planar inverted-F antenna for passive deep brain stimulation implants

A compact meandered three-layer stacked circular planar inverted-F antenna is designed and simulated at the UHF band (902.75 – 927.25 MHz) for passive deep brain stimulation implants. The UHF band is used because it offers small antenna size, and high data rate. The top and middle radiating layers are meandered, and low cost substrate and superstrate materials are used to limit the radius and height of the antenna to 5 mm and 1.64 mm, respectively. A dielectric substrate of FR-4 of εr= 4.7 and δ= 0.018, and a biocompatible superstrate of silicone of er= 3.7 and d= 0.003 with thickness of 0.2 mm are used in the design. The resonance frequency of the proposed antenna is 918 MHz with a bandwidth of 24 MHz at return loss of −10 dB in free space. The antenna parameter such as 3D gain pattern of the designed antenna within a skin-tissue model is evaluated by using the finite element method. The compactness, wide bandwidth, round shape, and stable characteristics in skin make this antenna suitable for DBS. The feasibility of the wireless power transmission to the implant in the human head is also examined.

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.

Strategies for improving the thermal performance and comfort levels of a kindergarten in the mountains of Nepal

Located on the Annapurna trekking trail in Nepal, Siurung is a remote mountain village where outside influences are almost non-existent. The thermal comfort levels of a recently-constructed kindergarten are well below international standards because of the climate and poor building envelope. A TRNSYS model of the kindergarten has been used to predict the current occupant comfort levels and subsequently determine the most effective way to alter the traditional construction methods to improve comfort levels. Improvements investigated were: reduced air infiltration, roof and wall insulation (separately and together), installation of a smokeless stove and a combination of all strategies.The model predicted that in the current building the PMV ranges from -1.94 in October to - 0.99 in July. It also predicted that the current PPD (%) ranges from 100 in January to 26 in July. With the combination of strategies, the predicted PMV values were all improved to between -1.08 and +0.34, and the PPD values of all months except January were reduced to below 10%. When improving the comfort levels of an existing school, reducing air infiltration, adding roof insulation and installing a smokeless stove are the most effective strategies. When constructing a new school, however, reducing air infiltration and adding insulation to the walls and roof are the most effective and feasible strategies. If a smokeless stove can be afforded and transported to the site, it is recommended that one be installed as it provides a more significant improvement than any other single strategy.

Thermal comfort in outdoor places a multicultural perception

The outdoor places are receiving more importance being contributing in the social cohesion and sustainability within societies. Providing comfortable sustainable urban places is an important factor affecting their success especially in multicultural areas where climatic conditions are perceived differently according to the diversity of users. Different design elements such as design form proved to be able to improve the outdoor thermal comfort. However, the integration of the climate dimension in the design process of outdoor places is lacking due to insufficient interdisciplinary work between urban climatology, and urban design. The main aim of the research is to examine the influence of cultural and climatic background on users’ thermal sensation and comfort within the same context. The methodology of the research is provided through quantitative analysis of a case study in Melbourne, Australia as one of the global cities characterized by the diversity and plurality of its population. The case study approach is adopted in order to examine the users’ thermal comfort within its contextual variables. Multiple sources of evidence such as climate measurements, questionnaires and observations are used to ensure the validity of results. The findings are to contribute to the quality and equality of design for outdoor urban places.

Effect of personal and cultural diversity on outdoor thermal comfort perception

The urban squares are the gathering places where people interact with each other. Therefore, they are seen as important places contributing in the integration and social cohesion within societies. To ensure equality in urban places, designers are to take into considerations the need of the diverse nature of different users. This task is hard especially in global cities where populations are characterized by their cultural plurality. To ensure the creation of successful urban places, the designer is to take the comfort of users into consideration. However, the outdoor thermal comfort is not easily assessed as it examines the climatic and personal variables for users. This paper aims to contribute in assessing the thermal comfort for users of different personal and cultural background in Melbourne city, Australia as one of the global cities characterized by the diversity and plurality of its population due to migration. A case study approach is adopted to examine the users’ thermal comfort within the contextual variables of Federation Square. Multiple sources of evidence such as climate measurements, observations and questionnaires will be used to ensure the validity of results. The findings are to contribute in the quality and equality of design for outdoor urban places in multicultural cities.

Effect of thermal adaptation on outdoor comfort perception

Thermal comfort in outdoor places has proven to have a strong relationship with their users’ attendance and behaviour [1]. Creating comfortable places is therefore to be considered a crucial part of the design process, as taking it into consideration help increasing the social integration between people and therefore fosters sustainability within cities [2]. With the increasing number of migrants within global cities, a new challenge has been facing thermal comfort studies. This challenge is related to the different cultural and climatic origins of those migrants and how they can adapt to the new climatic conditions they are to move in. This paper aims to explore the impact of thermal comfort adaptation on users’ thermal perception in multicultural cities. Consequently, a quantitative field study is applied in Melbourne city, Australia in order to investigate peoples’ outdoor thermal comfort. The analyses were based upon the measurement of climatic parameters that were monitored simultaneously with a questionnaire to determine users’ thermal comfort perception in relation to their time spent in the city. The findings of thermal comfort investigations could be applied into improving the quality of urban areas within global cities and therefore promote the integration within individuals in those societies.