Lioba Rubik

Fairteiler 3.0: An earth fridge for HTW Berlin

From Course to Campus Intervention: An Electricity-Free Community Fridge

Project Type: Practice-oriented university course / Teaching project
Institution: HTW Berlin (Wilhelminenhof campus)
Year: 2022 (summer semester)
My Role: Co-concept & Course Facilitation, Process Design, Research Guidance, Prototype Support
Project Partner: Laura Pelizzari
Cooperation Partners: Foodsharing e.V., Material Mafia, Haus der Transformation
Funded by: Treptow-Köpenick

Overview

What happens when a university course becomes a real campus intervention? Fairteiler 3.0 is a student-built, electricity-free earth fridge at HTW Berlin’s Wilhelminenhof campus — a functional food-sharing station that uses the stable cooling of the ground to keep produce fresh without any electricity. It was designed, researched, prototyped, and built by 12 students over one summer semester, with support from local cooperation partners and funding from the district of Treptow-Köpenick.

The project lives at the intersection of sustainable design, participatory pedagogy, and civic infrastructure — turning a university course into a tangible, community-serving artefact.

The Challenge

Food waste is a systemic problem with local solutions. Campus environments generate and receive food that often goes unused — yet existing sharing infrastructures (like refrigerated “Fairteiler” stations run by Foodsharing e.V.) are energy-intensive and expensive to operate. The course brief posed a design challenge that was both ecological and civic:

How might we create a low-tech, community-accessible food storage and sharing station that functions reliably without electricity — and that could be built by students, with local materials?

Beyond the design challenge itself, there was a pedagogical dimension: guiding a group of 12 students through an open-ended, real-world project — from first principles to finished prototype — within a single semester.

My Role

Together with Laura Pelizzari, I co-developed the course concept and designed the overall learning journey — balancing structured input with open-ended student-led exploration. My contributions included:

  • Designing the participatory course format and facilitation arc
  • Introducing frameworks and tools (including the decision matrix) to structure complex group decisions
  • Connecting students with cooperation partners and co-organizing the Material Mafia workshop
  • Guiding the team through iterative design development — from conceptual options to buildable prototype
  • Supporting project documentation and knowledge transfer


The role required navigating between two modes simultaneously: design educator and project facilitator — ensuring students were developing their own competencies while the project was also progressing toward a real, functioning outcome.

Approach & Process

The course was designed to be participatory and hands-on from the start. Rather than delivering a pre-defined brief, we built the problem space together.

Phase 1 – Understanding the System The semester began with an in-depth introduction to the logic and physics of earth fridges: how ground temperature remains stable at around 8–12°C at a depth of 1.5 metres, making it a reliable passive cooling system across seasons. Students explored existing examples, food-sharing infrastructures, and the local context of campus life.

Phase 2 – Research & Decision-Making Students moved into their own research phase, working with a structured decision matrix to evaluate key design parameters: Where on campus should the fridge be located? What structural form should it take? Which materials were best suited for exterior, long-term use — and ideally available as secondary materials? The matrix helped the group weigh sustainability criteria, accessibility, aesthetics, and practical constraints simultaneously.

After careful consideration, a site was chosen: the grounds of the Haus der Transformation — a shaded corner of the small green area on campus, sheltered by a wall, providing both the necessary conditions for ground cooling and natural shade.

Phase 3 – Material Workshop at Material Mafia One of the early design decisions was to use AluDibond — a composite aluminium panel often available as second-hand material and highly durable for exterior applications. To give students hands-on experience with this material before committing to it in the final design, we organized a workshop at Material Mafia, where participants learned cutting, drilling, and joining techniques. This experience directly informed the final design and helped students assess what was realistically buildable.

Phase 4 – Design Development & Prototype The final design that emerged was both technically clever and spatially elegant. The structure consists of:

  • A wooden above-ground structure rising 2 metres, anchored at the chosen site
  • A 1.5-metre hole dug into the ground directly beneath the structure — this is where the passive cooling happens
  • A suspended fridge unit, hanging from the wooden structure via a pulley-like mechanism


When the fridge is pulled upward, it opens two integrated shutters and rises to the level of the wooden frame — where it can be arrested in place, making it fully accessible for people to retrieve or deposit food. Once done, it is gently lowered back into the ground, where the earth keeps its contents cool without any external energy input.

Phase 5 – Documentation & Knowledge Sharing The team produced an open-source build guide documenting the full process — materials, measurements, construction steps, and design decisions — so that others could replicate or adapt the Fairteiler 3.0 for other locations.

Outcomes & Impact

  • A fully built, functional earth fridge installed on HTW Berlin’s Wilhelminenhof campus
  • 12 students developed hands-on competencies in participatory design, decision-making, and working with real materials and real constraints
  • An open-source build guide enabling replication of the concept
  • Active collaboration with Foodsharing e.V., Material Mafia, and Haus der Transformation — embedding the project into existing local networks
  • A tangible contribution to campus food-sharing infrastructure and local food waste reduction

Reflection

Fairteiler 3.0 is an example of what education can produce when it is oriented toward real-world impact. The course format — participatory, research-driven, and grounded in actual making — meant that students weren’t just learning about sustainable design in the abstract. They were navigating real constraints, making real decisions, and building something that would serve their campus community long after the semester ended.

The project demonstrates how teaching can function as a design intervention in itself: using the university as both a laboratory and a community actor, and turning students into agents of practical, ecological change.