Smart Cities Tiny House ERA

Introduction

Hello, my name is Edmond Lascaris and I'm a Local Government Officer at the City of Whittlesea in Melbourne Australia. I work in the Sustainability Environment Department and for the last ten years I've been doing outreach program in local primary and secondary schools and libraries teaching sustainability by using technology, such as environmental sensors, to engage students.

I use a little computer called a Raspberry Pi which was developed in the UK to improve computer literacy.

The irony is that the Raspberry Pi can also be used to improve environemntal literacy and climate change literacy.

They was we do this is to build sensors to monitor the enviornment.

For example, we have local frogs and platypus that are susceptible to floods and drought. We use water level sensors to help monitor the health of these waterways.

Students learn to build sensors, collect and process the data so that they can better understand or solve an environmental problem.

The sensors give students real data on the world around them and I think this makes the subject matter more real and tangible to students. Its also an important part of the modern pedagogy especially where inquiry based learning in involved.

For the past two years I've been teaching a Smart Cities course at the Whittlesea Tech School in Melbourne.

Raspberry Pi

One of the most important computing tools I use is the Raspberry Pi.

If you're not already familiar with the Raspberry Pi it is a small credit card sized computer that only costs a few tens of pounds. It was designed to encourage more young people to start hacking and learning about technology. You just need plug in a monitor, mouse, keyboard and a small power supply. It was developed in the UK by researchers from Cambridge university to help improve computer literacy skills among young people.

Its also a great tool to use for Climate Change literacy.

Smart Cities Tiny House

This year we decided to give the Smart Cities course a focus on Tiny Houses.

What is the Smart Cities Tiny House course about?

Interest in Tiny Houses is growing because of the high cost of energy, living and housing in general.

The Smart Cities Tiny House course evolved primarily to help students understand how to build an energy efficient house. The students will build a fully functioning replica of a tiny house that they can test and experiment with. Initially the house is 2m by 2m.

If you build small you can also invest in technology and materials that will keep your house cooler in summer and warmer in winter. It is a simple housing model for students to explore.

Once students understand the Tiny House model they can be better equiped to make more informed decisions about their own home or even their school.

What do they do in the Tiny House course

Measure, Make and Monitor is out motto.

The activity is broken down into Three key components:

• Measure - energy calculations for the Tiny house - for example, calculating heat gain and heat loss through a wall or window

• Make - materials and equipment used to build and power a Tiny House - insulation, air tight membranes, solar panels and even ventiallation systems with heat recovery. There are so many things to build if they choose. This is the fun part.

• Monitor - Enviornmental monitoring equipment for the Tiny house - temperature sensors and the ability to log and monitor changes.

The Monitor phase is very similar to the opportunity offered by Centrica.

All these components are easy to teach if broken down into smaller modules. Building the Tiny house, testing its performance and design modifications will make this an interesting subject for students.

Students can also compare their design against other teams and schools.

What sort of energy calculations

The easiest starting point is to look at heat gain and loss through wall.

Then we can compare these values to windows. Even double or triple glazed windows have poor thermal performance relative to walls.

We can also compare Tiny houses to larger houses. Students find that the high surface area of large homes means that they require more energy for heating and cooling.

We also have a solar PV system that the students built. It runs on a 200 Watt solar panel and has a 10 kg LiPO4 battery (1.4 kWh, 120 Ah). Such a small system makes it much easier for students to understand how much energy the system can provide.

What materials and equipment do you use in the Tiny House

The Tiny house is made using pine or plywood as the structural support.

Polyester insulation insulates the structure and special membranes make the wall structure air tight.

I have a small model of a wall section here, but the real wall is approximately 20cm in thickness to accommodate the insulation. There also needs to be external cladding such as metal or wood.

The house shell will allow students to test some theories about energy conservation.

For example, temperature changes can be moderated using thermal mass such as concrete.

Even though the structure is airtight it can breathe using a ventilation system withe heat recovery.

Students can build a temperature sensor that monitors the temperature on the inside and outside of the structure. Thsi tells them if the Tiny House is performing as designed or when stressed such as on a really hot or cold day.

Monitoring Equipment for the Tiny House

The monitoring equipment is simple in theory. It is a temperature sensor inside and outside the house.

Students can be shown how to build the temperature sensor.

The sensor data is transmitted to The Things Network in the cloud. Once the data is uploaded any student or school from anywhere in the world can download the live data.

We also use a Raspberry Pi to monitor the energy system for the Tiny House. The Raspberry Pi can monitor how much electricity the solar PV panels are producing, how much charge is available in the battery, and how much energy devices are drawings from the battery.

Energy Efficiency in Schools

Based on the experience in the Smart Cities Course it is really easy to teach students how to access data from sensors placed in their own schools.

The data obtained from Centrica is available on the internet and can be read by Raspberry Pi computers.

Students can learn how to present the data in a Dashboard they build on the Raspberry Pi using software called Node-RED and monitor data trends. For example they can monitor electricity use and gas use. Using sensors they can also monitor internal and external temperatures.

Student engagement

Using a small computer such as the Raspberry Pi which neatly fits into the hands of a child. They can learn how to program this little device which is a great entry to the digital world.

Students always like building things. We teach students how to solder and build the sensors.

Students are also getting experience building the components of the Tiny house that they can then modify and improve on.

And finally we are preparing video lessons that Australian students from diverse backgrounds are developing.

Giving students the opportunity to build a Tiny House at school and then test its performance is fun and exciting for students. Last year we built several elements of the Tiny house including a wall section, solar PV power supply with battery

In 2022 the students helped solder temperature sensors for the Tiny House that communicate using LoRa (Long Range Radio).

We did calculations based on the area of a big house versus the area of a Tiny House to show that a Tiny House will lose or gain much less energy to the environment because its surface area is smaller.

We also showed that energy loss and gain is greatest through windows and we compared windows to walls. There is a huge difference.

The students also built a wall section using materials that we saw being used in a Passive house on Grand designs.

Hence the Smart Cities Tiny House course was born. Over the last 4 years the students have been building the foundation for this course. Tiny Houses would be a good solution to high energy costs because they can be designed to be warmer in winter and cooler and summer if properly designed.

Tiny House Wall

The aim is to build a small Tiny House that can be built by students. The construction will include special insulation for the walls and air tight membranes.

Here is a mock up of a wall section.

Once the Tiny House is built the students can do energy calculations. It is much more interesting doing calculations on a Tiny House that you've just built. And once the principles are known these same calculations can be applied to their own homes or school.

Tiny House Energy

The Tiny house has a solar PV panel and battery to provide enough energy to power lights, raspberry Pi computer, laptop, mobile phone, electric bike, refrigerator, etc.

A Raspberry Pi computer connected to the PV system can tell the students how much energy is in the battery, how much energy was collected during the day and how much energy different appliances draw.

The assembly of the electronics can be done safely because all energy sources are removed and only later connected by adults away from the students. However because the students have built the system they can connect with the data.

Importantly they can mentally equate battery sizes, solar PV sizes, and appliances to energy flows and losses. In a Tiny House you need to manage energy carefully, something that we will all need to do in a low carbon future.

Tiny House Temperature Sensor

So how do you test to see if your Tiny House is really performing as it should?

You add environmental sensors such as temperature sensors inside and outside the structure and you gather data. This strategy invites Enquiry-Based learning, collaboration and sharing.

Students have an objective to make their house as comfortable and low energy as possible. If its hot outside - how can they keep their house cool on the inside.

There are a variety of strategies they can use. A large thermal mass inside their house will help to delay heating. Insulation helps too. Vegetation on the outisde of their house will help prevent direct solar gain. They could use the thermall mass of the Earth and ground to help bring cool air into their house.

The same is true for cool temperatures. How can they keep their occupants warm. Humans generate 100 Watts of heat. Can we use their better. Can we capture more energy from the sun to keep us warm.

In all these experiments simple temperature sensors can give vital clues about how each student team's Tiny House is performing. And each passing season presents new challenges and opportunities for improvement.

Building Temperature sensors

Some students in secondary school in the UK may want to build their own temperature sensors for this project. Instructions are provided. The temperature sensors are connected to little computers and send their data to the internet. This way they start to experiment with what is called The Things Network.

Platypus project

The focus of my work at Local government relates to maintaining healthy waterways. There had been a series of pollution events at a local waterway in 2017 that were possibly affecting the health of local platypus in the Plenty river.

I was teaching students at a local library and collectively we decided to work on an environmental sensor to help detect these pollution events.

This was my first real experience with building sensors, sending data and analysing it on a Raspberry Pi. The students took up the challenge and helped launch the sensor.

From the student's perspective it was like working on a satellite for a space program.

They needed to use solar PV panels, they had to work on energy management systems and batteries. They worked on the communications equipment and the small computer brain within the sensor. They also entered their project in a local ICT competition called the Young ICT Explorers competition and finished second in the state.