INQUIRY BASED SCIENCE EDUCATION STUDENTS OF 1° YEAR SECONDARY SCHOOL

DESIGN A LOW ENERGY HOME Daniela Bellomonte e Laura Gambino

University of Palermo – Physics Education Research Group

Testing a house model1. How to keep warm your house model

1° Activity:Four groups of students are provided with different house models having the same dimensions and constructed with different materials (polystyrene, wood, cardboard and foam core board). In each model, there is a heater (40 Watt light bulbs covered with aluminum sheets) and a temperature sensor placed on the opposite wall.

Learning objectives: The main goal of the activity is to identify the material of the walls as one of the most important factors in the heat dispersion of the house.

2. How is temperature distributed inside your house model?

POLYSTYRENE FOAMCORE BOARD WOOD

“SUN”

POLYSTYRENE AND WOOD HOUSES

TWO SENSORS

POLYSTYRENE

WOOD

EXPLORE AND EXPLAIN

ELABORATE

CARDBOARDStudents are asked to turn on the heater and record the temperature for 10 minutes using software logger pro. Students are then asked to turn off the heater and record the temperature for additional 10 minutes. Additionally, the four different groups of students measure how much energy is necessary to warm each house model 5°C higher than the environment.

Results:Each group reports to the whole classroom its results in order to illustrate how fast different house models heat up and then cool down under the same conditions The polystyrene house heats and cools very fast, whereas the wood house heats and cools very slowly. The cardboard and expanding foamcore board house models curves are both intermediate.

The right-handed graph shows the temperature curves from various house models under the same thermal conditions.

At the end of the activity, students learned to identify the material of the walls as one of the most important factors of heat dispersion when the house is heated. This is due to the different characteristics of the materials being used.

Learning objectives:The main goal of the activity is to understand that temperature variations occur at different heights inside the house.

2° Activity:Four groups of students are provided with different house models having the same dimensions and constructed with different materials (polystyrene, wood, cardboard and foam core board). In each model, there is a heater (40 Watt light bulbs covered in aluminum sheets) and two temperature sensors placed at the same distance from the heater but at different heights from the floor.

CARDBOARD

Students are asked to turn on the heater and record the temperature for 10 minutes using software logger pro.

Results:Each group reports to the whole classroom its results in order to illustrate that, in each model, the greater the distance from the floor the higher the recorded temperature is. The following graphs show two different heating curves in each model.

At the end of the activity, students learned that, inside the house model, the highest part is also the hottest. This is due to the hot air that ascends.

3. What is the effect of sunlight on the temperature inside your house model?

Learning objectives:The main goals of the activity are to analyze the solar effects on the house temperature and to make evident that the house model temperature is affected by the absorption and conduction of wall materials.

3° Activity:The students are provided with two different house models having the same dimensions and made by different materials (polystyrene and wood). The two house models are equally illuminated with a light bulb (200 W) simulating the sun. Inside each house, there is a temperature sensor located on the wall facing the lightened wall.

Students are asked to turn on the light for 30 seconds and record the temperature using a software logger pro. Students are then asked to turn off, remove the light bulb and record the temperature for 10 additional minutes.

At the end of the activity, students learned to consider the material used in the wall as one of the most important factors of heat absorption and conduction when the house is heated by the sun. The polystyrene house heats very fast, whereas the wood house heats very slowly. This is due to the different characteristics of the materials being used.

Results:The right-handed figure shows two heating curves when the polystyrene and wood house models are illuminated with a light bulb (200 W) simulating the sun. The heating, in the polystyrene house model is faster than in the wood house model.

IBSE character: learning cycle

Before experimenting, in a preliminary discussion students plan investigations, develop hypotheses, distinguish alternatives and debate with peers.After experimenting, they interpret data, and analyze the results. Students compare the results of their experiments with their assumptions and proceed in identifying and explaining any differences.

1° activityProblem and questions

In winter, we want to maintain warm our house and we need energy for this.

How can you maintain warm your house? Could you identify the different factors influencing heat dispersion?

ENGAGE

Known and assumptions

Giovanni said: “ I think that the wall should trap the heat”

Giulia said: “I think that a wooden wall is the best one since in the mountains, all houses are built using wood”

Sara said: “I thinks that walls should be thick and made by different materials”

2° activityProblem and question

It is easy to observe that inside a heated room different places do not have the same temperature.

How can we identify the places with higher temperature?

Known and assumptions

Alessia said: “In my room on the second floor there’s a higher temperature that in the kitchen on the first floor ”.

Marta said: “At my place, we have the opposite experience. This is because the rooms on the highest floor are closer to the sun”

“In my opinion, there will be no temperature differences within the house” (Giuliana, Giovanni, Alessandro)

“In my opinion, there will be differences in temperature within the house” (Toti, Marta, Giulia, Christian)

3° activityProblem and the question

It is easy to observe that bodies are heated by the sun shining. This can be also the case for walls of our house models.

How materials can influence temperature inside the house?

Known and assumption

Iolanda and Giuliana said “When it is really hot, it should be better to paint the houses white. We dress with clear colours in the summer in order not to suffer the warmth too much”

Samuele said “It is warmer if you stay closer to a glass window”

Gianmarco said “It would be better to make walls ticker. This would insulate properly”

Why heating and cooling are so fast in the polystyrene

house…?

PO

POLYSTYRENE HOUSE CARDBOARD HOUSEWOOD HOUSEFOAMCORE BOARD HOUSE

EVALUATE

At the end of activities, students are evaluated by presenting the experiments to their parents and teachers during a “science day”.

ELABORATE

ELABORATE

I.C.S. “Guglielmo II”, Monreale, Palermo, ITALY