The unit Designing a Low Energy Home is divided into 4 subunits, which can be used independently or sequentially. Each subunit can take different directions and emphasis depending on the curriculum and particular learning aims of the teacher.
Subunit 1 is explicitly designed to introduce lower-secondary school students to thermal energy transfer. It can also be used to engage upper secondary school students in the subject and introduce them the other subunits.
Sununits 2, 3 and 4 analyze the different processes of thermal energy transfer (conduction, convection and radiation). Subunit 4 also intends to introduce pupils to infrared thermography, thermal imaging and thermograms, i. e. infrared imaging science.
The Unit is enriched with many ICT activities in which temperature sensors, MicroComputer Based interfaces and software are used to coolect data, visualize them in real time and analyze the results.
The project we want to develop in this Learning Unit deals with the idea of a model house that uses less energy to heat the rooms and makes use of scientific discoveries and technological resources to minimize energy consumption. The house analysis will be the starting point to explore some important scientific concepts related to heating and cooling of bodies and to heat transfer.Even if we will work with models of polystyrene, wood, plastic and cardboard, warmed by a light bulb placed inside, we will apply the same principles of science and engineering that are taken into account in the construction of a real house. In many countries a large percentage of energy consumption is due to heating and cooling of buildings. Therefore, the search for more efficient methods of construction to improve the energy efficiency of buildings is extremely important. Less energy means less fossil fuels and thus a lower amount of carbon dioxide in the atmosphere. Your generation has the task of doing something about energy efficiency and then you need to know the problem to make responsible choices.
Some initial considerations
We begin our work by observing the characteristics of some houses. Then, we try to understand why they are very different from each other.
Although our goal is to build a model home that is efficient from an energy point of view, that has a constant temperature and can also be heated by the sun, we will start working with models to familiarize with the materials, construction methods, and measures necessary to evaluate the project.Your teacher will provide you with the models on which we will use standard procedures for measuring the thermal performance of a house. In order to cool a house (or as it is commonly said losing heat), there must be a difference in temperature between the inside and the outside. The inside of the house must be warmer than the outside. Because you cannot cool your classroom at 0 ° C, we will try to heat your model house at 15 ° C above the environment temperature. This is done with a heating bulb placed inside the model.As in a real home, what matters is how long the heater must stay switched on to keep the house warm. The higher the inner temperature, the more energy is used and the more you heating bill will be. To mimic this situation, we will record the percentage of time the heating lamp should stay turned on to maintain the house at 15 ° above ambient temperature. We will perform the same test in other conditions, trying to understand why different results are obtained.