Riding the Crest of the Wave
'Crest' is an international awards scheme, designed to encourage school students to apply their knowledge to solving practical problems. The scheme meets IPENZ's goals in that it supports the technology curriculum and helps to promote careers in engineering and technology to young people. It offers students a chance to think creatively, and to develop the practical and technical skills that scientists and technologists must employ alongside their theoretical knowledge. And it helps them to bridge the gap between academic learning and the world beyond school.
This case study is reproduced with permission from e.nz magazine. Subscriptions to e.nz are discounted for schools and TENZ members.
Background
Heat Exchanger CREST came to New Zealand from me UK in 1989, initially supported by Massey University staff on a voluntary basis. Since 1999 the Royal Society of New Zealand has administered the programme, with the support of a Board. Close to 1600 students across New Zealand are currently engaged on CREST projects.
Awards are offered for individual and group projects, graded from First level, for students in Years 6-8, through Bronze and Silver, up to Gold level, which is for Year 13 students. The stepped programme reflects age and curriculum levels, and coaxes the students progressively towards independent learning. They are required, for example, to complete a Silver award before attempting the Gold awards, in which the standard aimed for is "above what would be expected of a competent student in Year 13", and a high level of creativity and independence is called for.
Unlike most awards, the CREST scheme is not a competition; it rewards all projects that meet the criteria. This means that students of different abilities can succeed, with projects of varying degrees of sophistication. It does not mean, however, that the awards are easy to achieve, or the standards low. Assessment criteria require at all levels that students apply knowledge to real problems or opportunities, demonstrate creativity in finding or solving a problem and perseverance in overcoming the inevitable difficulties, and communicate the process and results effectively.
Plainly, expectations of students are high; but the framework involves the assistance of a supervising teacher for each project, who acts as an advocate for the students, and of a "consultant" with suitable expertise. The consultant helps students devise ways of testing their ideas, and helps to keep projects focussed and realistic. In more sophisticated projects, part of their role may be to provide access to resources and facilities outside of school.
At all levels students are required to document their projects in a detailed log. At the higher levels they are asked to exercise some independence and initiative in organising and timetabling their projects, finding resources and information, and interacting with their consultants.
There is clear evidence that the CREST awards are a valuable influence in motivating young people to consider tertiary studies and careers in technology-related areas. In this respect the consultants are crucial. They offer students extended contact with role models – a major influence on career decisions according to the research. Resourcing and testing students' solutions may also involve visits to research or industry facilities, opening further windows into the worlds of tertiary education and work.
Hugh Morris of the Department of Civil and Environmental Engineering at the University of Auckland emphatically endorses the programme as a careers promotion tool, and believes that even the Bronze CREST awards can impact significantly on the numbers of students taking engineering at university, as an authentic taste of technology at an early stage in their education shapes subsequent subject choices. The higher-level awards can affect career choices still more directly; Dr Morris cites the work of Chris Smaill, who until recently taught at Rangitoto College and used Silver CREST regularly to support senior science students: "Chris's work with Silver CREST was worth four or five students a year to us."
Energy from Effluent
Haydn Luckman entered his Gold CREST project in the NIWA Auckland City Science and Technology Fair 2002, where it was selected for the National Science Fair. There Haydn carried off the Genesis Energy Premier Award in Technology, and a trip to London to attend theYouth International Science Forum. He was also guest exhibitor at the Beijing Youth Science Creation Competition en route.
His technological adventure began with an idea for reducing the cost of domestic water heating by utilising the heat that disappears down the shower drain with the wastewater. He wrote a proposal, and it became clear that he needed to extend his theoretical knowledge and practical skills before he could test his idea. He needed to learn the basics of heat transfer, computer modelling and prototype construction; and to this end his assessor suggested he needed the help of an engineer.
With Dr Joe Deans of the Auckland University School of Engineering as his consultant, Haydn gained access to the knowledge and tools he needed to pursue his vision – the project "took my understanding of theories learned at school to a higher level". The university allowed Haydn to use facilities such as the Thermodynamics Laboratory, where much of the testing phase of the project was carried out. He learnt to manage his time effectively and gained a practical understanding of design processes. CREST also developed his verbal and written presentation skills, bridging the gap between school and tertiary-level expectations.
The university experience was decisive in Haydn's choice of tertiary studies. As he explains it, "During this time I got to see a great deal of what goes on in the School of Engineering, and I liked what I saw!" His interest in physics and engineering was long-standing, and had been nurtured by a succession of school technology projects. Now it was confirmed in a practical way; and a "final push" took the form of a $1000 scholarship from the University of Auckland for his entry in the Auckland Science Fair. Haydn is now in his first year of a conjoint engineering/Commerce degree.
The Project
Water heating accounts for around 40% of typical household power usage, and a good deal of it is wasted. For example, roughly 12 litres of water goes down the shower drain per minute, still at a temperature of about 40 degrees. Haydn's project, "Energy from Effluent", aimed to develop a heat exchange device for recovering heat from warm wastewater, and using it to pre-heat incoming cold water, thus saving power by reducing the draw-off from the hot-water cylinder for each shower. His preliminary research established that no such device was available.
Dr Deans provided a computer model, with which Haydn examined possible design concepts. A model using two coils of 3/8" copper pipe, one inside the other, promised the best compromise between cost-effectiveness and efficiency. The pipes were coiled on a former, which had to be constructed from scratch. Among other problems to be solved, the reduction in cold water pressure had to be minimised, and the cold/hot contact and differential maximised.
Haydn built a prototype, and tested it on a rig at the School of Engineering using thermocouple temperature readings at various temperatures and flow rates. Modifications after testing increased the power output from 4.5kWto 4.8kW.
The unit potentially recovers about 40% of its cost per year, and has real commercial potential; but Haydn decided against patenting the system because of the cost involved, and the difficulty of exploring manufacturing and marketing feasibility while he is engaged in university studies.
CREST depends upon the goodwill of volunteer consultants. IPENZ Members who are interested in contributing to the CREST programme as consultants can contact Angela Christie ([email protected]) at IPENZ, or Jessie McKenzieat the Royal Society ([email protected]).
Janet Hughes
