Oliver Kinnane

Mechanical and Thermal Evaluation of Different Types of PCM-concrete composite panels

Abstract The thermal mass of construction materials can be used to reduce the energy required for heating and cooling buildings. The heat storage capacity of concrete can be increased by incorporating phase change materials (PCMs) and hence providing a latent heat storage capacity. However, the addition of PCMs to concrete can reduce its conductivity due to the low conductivity of the PCMs. This hinders the efficient utilisation of the additional heat storage capacity provided by the PCM. Two types of PCM–concrete composite panels were manufactured. Firstly, a panel was formed by adding microencapsulated paraffin to fresh concrete during the mixing process. Secondly, butyl stearate was vacuum impregnated into lightweight aggregate which was then included in the concrete mix. In order to counteract the reduction in conductivity caused by the PCM, a second group of PCM–concrete composite panels were made using ground granulated blast-furnace slag (GGBS) as a partial cement replacement. The use of GGBS results in a denser cement paste which, for a given aggregate type, increases the conductivity of the concrete. This study aimed to establish which type of PCM–concrete composite material was most effective at improving the thermal mass behaviour of the panel and also to evaluate the effect that the PCM had on the relevant properties of concrete. The effect of GGBS on the thermal performance of the panels is reported.

GiveMe Shelter: a people-centred design process for promoting independent inquiry-led learning in engineering

ABSTRACT It has become increasingly common for tasks traditionally carried out by engineers to be undertaken by technicians and technologist with access to sophisticated computers and software that can often perform complex calculations that were previously the responsibility of engineers. Not surprisingly, this development raises serious questions about the future role of engineers and the education needed to address these changes in technology as well as emerging priorities from societal to environmental challenges. In response to these challenges, a new design module was created for undergraduate engineering students to design and build temporary shelters for a wide variety of end users from refugees, to the homeless and children. Even though the module provided guidance on principles of design thinking and methods for observing users needs through field studies, the students found it difficult to respond to needs of specific end users but instead focused more on purely technical issues.

Analysis of Thermal Comfort and Space Heating Strategy

Targets have been set to reduce the energy consumption in public buildings in Ireland by 33% by 2020. Space heating accounts for a significant portion of the energy load of public buildings. Diverse space heating strategies are often required to meet the requirements of spaces of various usage within public buildings, including within multi-purpose or event spaces. To analyse the thermal comfort of occupants and efficiency of the space heating strategy a post-occupancy evaluation was carried out on an event space at Dublin City Council local authority offices. The evaluation, based on the results of monitoring (temperature, energy), modeling and the assessment of comfort as perceived by occupants, has shown that thermal comfort is not adequately achieved. This is the case even though significant energy is being expended to achieve comfort levels via a current inefficient space heating strategy.

Influence of Ground Granulated Blastfurnace Slag on the Thermal Properties of PCM-concrete Composite Panels

The thermal mass of concrete within a building can be used as an energy storage system and hence reduce the demand on the auxiliary heating and cooling systems in the building. The heat storage capacity of concrete can be enhanced by adding phase change materials (PCMs) which provide a high latent heat storage capacity. However the addition of PCM to concrete reduces the conductivity of the concrete due to the low conductivity of the PCMs. This hinders the efficient utilisation of the additional heat storage capacity provided by the PCM. It is generally understood that the use of ground granulated blastfurnace slag (GGBS) as a partial cement replacement results in a denser cement paste which, for a given aggregate type, increases the conductivity of the concrete. The aim of this study was to determine if the use of GGBS influences the thermal mass behaviour of a PCM-concrete. Two types of PCM-concrete panels were manufactured. Firstly microencapsulated paraffin was added to fresh concrete during the mixing process. Secondly butyl stearate was vacuum impregnated into lightweight aggregate which was then included in the concrete mix. Half of the samples contained 50% GGBS cement replacement and consequently the effect of GGBS on the thermal performance is reported.

A Comprehensive Monitoring System to Assess the Performance of a Prototype House

This paper presents a monitoring system and methodology designed for the evaluation of a prototype house, and proposed as an exemplar for comprehensive domestic monitoring. This system will enable assessment of a wide range of parameters for proof of concept and technology of the prototype. Consumption, occupancy patterns, indoor air quality, thermal conditions and building efficiency are monitored so as to gain a real-time understanding of building performance and occupant interaction with the house. The broad range of parameters will allow quantification of the correlation between for example; occupancy and consumption patterns, or air quality and ventilation system operation. Results of this monitoring study will inform future design iterations of this housing product.