Evaporative Air Conditioning

Evaporative coolers have been known to purveyors of low-cost, sustainable technologies for years. Without the need for electricity, these cold containers have kept produce fresh from farms to tables, protecting against post-harvest losses in the field and food spoilage in hot pantries worldwide.

Now the concept has been applied to air conditioning. Manoj Patel Design Studio in Vadodara, Gujarat (India) has built evaporative air conditioners that can cool a room for days on a single tank of water. The studio designs new products from recycled materials, and they built their air conditioners from ceramics and stone, integrating them with potted plants. By filling rows of ceramic tubes with water, the prototypes maximize their surface area for optimal evaporation while retaining a small footprint.

Read more: This Air Conditioner for Homes and Offices Uses No Electricity, Engineering for Change. Previously: How to keep beverages cool outside the refrigerator: the botijo.

Zero Electricity Air Cooler

Eco-Cooler airco without electricity

Over 70% of Bangladesh’s population live in corrugated tin huts across the countryside. During the long summer months, temperatures reach up to 45° Celsius, making these huts unbearable to live in.

To address the issue, Grey Dhaka teamed up with volunteers from Grameen Intel Social Business Ltd to create the Eco-Cooler – a zero electricity air cooler, which uses re-purposed plastic bottles cut in half and put into a grid, in accordance to available window sizes.

Based on wind direction and airflow pressure, the Eco-Cooler has succeeded in decreasing the temperature in tin huts by up to 5° Celsius. After initial tests, blueprints of the Eco-Cooler were put up online for everyone to download for free.

Thanks to Adriana Parra.

Adapting to Climate by Being a Nomad within your own House

While some people seasonally move between dwellings, others are nomads within their own houses. In such diverse places as Iraq, Algeria, and India, climates and cultures may vary, as do the directions and rhythms of movement. But all share migration within the dwelling as a primary mode of adaption to climate.

Families living in traditional courtyard houses of Baghdad, without mechanical ventilation or heating, migrate by day and season for comfort. In September or October, they move around the courtyard to rooms facing south. In April or May they shift to the north-facing rooms. In summer there is a daily vertical migration, the afternoon siesta being spent at the lowest levels and the nighttime sleep traditionally being taken on the roof under the stars.

old baghdad house

Picture: muhammadshnait91.tumblr.com

Such migrations mean that space is used with a freedom unusual in modern life and in the West. Recent correspondence from Mounjia Abdeltif-Benchaabane, a professor of architecture in Algiers, describes how rooms there have not traditionally been organized with regard to individual use or established purpose:

A living room becomes a sleeping room at night. Closets are full of mobile furnishings. In the morning everything is hung near windows to air out under the sun before being reused, perhaps in a different room. The kitchen is a multifunctional space. They cook on the floor even if they have modern tools.

A long-established Arab concern with privacy, in conjunction with the custom of migrating through the house, established the texture of some old cities like Baghdad. Since the roof is used for sleeping during nearly half of the year and the privacy of the family at night is fundamental, no house could look down upon its neighbor nor could one house look into the courtyard of another. The result was an effective building height control with advantages for solar access: no house could overshadow another, thus assuring wintertime light and heat to upper living spaces.

Quoted from “Ritual House: Drawing on Nature’s Rhythms for Architecture and Urban Design“, Ralph L. Knowles, 2006.

India’s Ancient Stepwell Architecture Cools Modern Building

“At the height of summer, in the sweltering industrial suburbs of Jaipur, Rajasthan in north-west India, where temperatures can hit 45C Pearl Academy of Fashion remains 20 degrees cooler inside than out, by drawing on Rajasthan’s ancient architecture. While the exterior appears very much in keeping with the trends of contemporary design, at the base of the building is a vast pool of water — a cooling concept taken directly from the stepwell structures developed locally over 1,500 years ago to provide refuge from the desert heat.”

Read more: Ancient ‘air-conditioning’ cools building sustainably.

Movable Shading Structures

movable shading structures

A house can be cooled in two ways. You can try to get rid of the incoming solar heat using air conditioning. Or you can try to prevent the sun from entering the house. The last option can be achieved by movable shading structures. The French house on the picture was built in 2009 by Karawitz Architecture.

Its shuttered bamboo skin can be used to keep the sun out in summer. The shutters can be opened in winter, exposing the large south-facing windows. The house, which stands in Bessancourt (not far from Paris), has no active heating or cooling system. Info + pictures. Via Build it solar. Thanks to Paul Nash.

Related: Window orientation and shading.

Window Orientation and Shading

window orientation and shading

“In sunny southern locations, protecting your windows from the sun is an important component of good window management. The first step is to know how the sun moves through the sky and to orient the building and place the windows in it so as to minimize direct solar admission through your windows.” Read more.

“Sustainable By Design provides a suite of shareware design tools to calculate the right dimensions and placing for your specific location, wherever you are.

  • SunAngle: our premier tool for solar angle calculations.
  • SunPosition: calculates a time series of basic solar angle data.
  • Sol Path: visualization of the path of the sun across the sky.
  • Window Overhang Design: visualization of the shade provided by a window overhang at a given time.
  • Window Overhang Annual Analysis: visualization of window overhang shading performance for an entire year.
  • Overhang Recommendations: suggested climate-specific dimensions for south-facing window overhangs
  • Light penetration: visualization of the penetration of sunlight into a room
  • Louver Shading: visualization of louvered shading system performance for an entire year.
  • Vertical Fin Shading: visualization of a vertical fin shading system performance for an entire year
  • Window Heat Gain: calculation of monthly heat gain through windows.
  • Panel Shading: visualization of the shading of rows of flat panel collectors throughout the year.”

Interesting follow-up at Treehugger.