Project Overview

Problem:

As part of a Sustainable Design class, four classmates and I were tasked with utilizing the characteristics of the flora and fauna of a chosen location to design a house with a minimal environmental footprint. Our group chose to design a house for use in Tabuk, Saudi Arabia. This city is situated on the largest continuous body of sand on Earth, has very little rainfall, and is supplied with ample oil, resulting in high water and oil consumption and a consequently large carbon footprint. The humidity in Tabuk fluctuates 40% daily and 30% seasonally, and the temperature swings by 20 - 30 degrees daily. We chose this location because of its potential to become more environmentally friendly, and because of its challenging natural environment.

Solution:

Our team set the goal of designing a house that would be for a family of at least 4 people, maintain a comfortable temperature (68 - 78 degrees) and humidity range (20 - 60%) without an HVAC system, have 70% passive solar heating and cooling (30% PV solar powered) of water and air, have sufficient air ventilation (2x/3 hours), provide water collection and greywater treatment, and cost ~$500,000 to accommodate an upper-middle class family. We drew on the adaptations of Namibian beetles, termites, white desert snails, and umbrella thorn trees to design a house that would meet these goals. I was the leader of our team, and was in charge of all of the computer aided design for the project.

Design Process

First Iteration

Our original design of the house was inspired by several elements of desert life: a stilted structure inspired by camels, a wind cone and chimney inspired by termite mounds, a dish-like roof inspired by the umbrella thorn tree, and a water collection system inspired by Namibian beetles.

Wind Chimney Details

The large opening at the front of the house was intended to capture wind that would then be drawn up in to the warm chimney and expelled. This design was inspired by the induced flow model seen in termite mounds. The home itself is connected to the thermal chimney within the wind cone structure, so as wind induces the flow of hot air out of the chimney, it draws warm air out of the house as well. The structure additionally provides shade for the house, much like the shell of the white desert snail.

Water Collection Details

The outside of the wind chimney would be textured metal mimicking the Namibian beetle's shell, allowing dew and rain water to collect on its surface. The water would then flow down the chimney and into an underground water collection unit, via a living roof that provides additional shade over the house and a back patio area. The dew and rainwater collection system was inspired by the Namibian beetle, which collects dew on its textured back and stands on its head to guide the water to its mouth.

Air and Water System Summary

The air and water systems are interconnected via an underground water cistern that acts as a thermal mass to cool incoming air. The air enters through pipes above ground that are shaded by the solar panels, and is cooled as it travels to and within the water cistern below the property. The cool air is then drawn up into the home by the draft caused by the solar chimney and wind cone, according to the Venturi Effect.

Revised Design

In order to minimize the amount of heat gained through the side windows of the wind cone, we decided to remove the disk-like roof and replace it with wing-like canopies over these windows. We also removed the stilts, and moved an additional floor of the house underground to take advantage of the ground's thermal mass. Lastly, we optimized the wind chimney by widening its base and adding a curved cover that pivots with the direction of the wind.

Additional Components

Behind the house, we added several more rows of solar panels to increase energy production. We decided to situate these panels atop a structure that would serve as the roof of an outdoor patio area. This patio would be surrounded by a wall so that women would be able to spend time outside without needing to wear their traditional hijab that is needed in public areas.

Final Product

According to our calculations, this house would provide ~13.5 gallons of water per day from condensation and ~15 gallons per day from rain water, on average. A temperature of 73 degrees would be maintained through passive cooling and heating, and air would circulate once every 1.6 hours. All electricity would be generated by the solar panels. The home would cost approximately $300,000, and would be able to house 6 people.

I personally earned a citation for academic excellence for this project, for "outstanding performance in all aspects of the course, especially for creative design and strong engineering skills in the term project”.

Biomimetic House