No Air Conditioner Needed: These Buildings Cool Themselves
Bioclimatic design could go a long way toward reducing energy costs—and our carbon footprint.
The average temperature for June and July in Pomona, California, is in the 80s, and the building that Pablo La Roche’s office is in doesn’t have air conditioning. “But it’s still around 73 degrees inside, and very comfortable,” he said. La Roche, a professor of architecture at the California State Polytechnic University at Pomona, works out of the Lyle Center for Regenerative Studies, which was designed to use ventilation, airflow, and the natural patterns of the sun to regulate the building’s temperature. “The building becomes the air conditioner.”
It’s an approach known as bioclimatic design: using the environment around a building to passively manage the temperature and light inside, rather than mechanically heat and cool a space.
Structures designed that way are energy efficient, which leaves them with a smaller carbon footprint. Buildings contribute 40 percent to the total amount of carbon dioxide emissions in the United States. “If they were using less energy—and we could go a long way towards that with these passive structures—we could cut our emissions significantly,” La Roche said. “I think it’s incredibly important.”
Passively heating and cooling a building is far from a new idea. Early architects designing cities in the hot climates, like Morocco and Cairo, developed many of these solutions centuries ago. They built homes and buildings with natural ventilation that let air through cooling courtyards and into homes, and designed windcatchers to harness breezes. In the United States, Thomas Jefferson’s house in Virginia, Monticello, used skylights to vent hot air, and porticos to pull in cool breezes.
Building with energy and the environment in mind requires an intimate understanding of local climate, and the movement of the sun and wind. La Roche loves evaporative cooling systems, which mist the air with water to trigger evaporation, which brings down the temperature. However, that only works in places that aren’t already humid. “Depending on where you are, you’ll implement different techniques,” he said. You can cool a space by closing it up during the day, and opening it up during the evening to allow night breezes in, for example, or build with materials that can suck up heat. “It’s about understanding the mechanisms,” La Roche said.
In cold climates, or the wintertime, improved insulation can offset the need for mechanical heating, Leon Glicksman, a professor of Building Technology and Mechanical Engineering at the Massachusetts Institute of Technology, told The Daily Beast. Building facades can be designed to trap heat from sunlight during the day, while also minimizing the need for artificial lights, he said.
Today, the idea isn’t to eliminate mechanical heating and cooling systems entirely, but to use them only when necessary. Bioclimatic design can be high-tech, as well, La Roche said. He pointed to the Cooper Union building in New York City, which uses natural ventilation when possible, but has sensors that can detect changes in the internal climate, and kick on mechanical heating or cooling systems when necessary.
People tend to be more comfortable in buildings designed with these principles. “There’s more insulation, there are fewer drafts,” Glicksman said. Working in buildings with natural light has been linked to higher productivity, as has ventilation.
Climatically designed buildings make economic sense, as well, La Roche said. Lower energy requirements mean lower energy costs. In some cases, the initial investment is higher, but not always, he said. “If you put a window in the right place instead of the wrong place, it’s going to be the same cost,” he said. “But the cost to operate the building is going to be different, so if you put it in the right place, it will save you money after.”
Strategies like ventilation and cooling towers, though, haven’t caught on in a big way in the United States. Isolated architects and building owners are interested, and passive houses—which use only a quarter of the energy of a traditional home—crop up across the country. But the United States lags far behind other parts of the world. “We’re far behind where a lot of the Europeans and some Scandinavian countries are,” Glicksman said. “But the trajectory has been slow, and it’s not high on the priority list to do these types of things.”
Despite the long-term economic benefits of bioclimatic design, one of the barriers to wider implementation in the United States is still the cost. “Part of the problem is the people who build the buildings don't pay for the utility bills,” Glicksman said.
Energy efficiency codes, which set standards for new buildings, can push developers to construct in energy-efficient ways, but they vary widely between states. And codes won’t be able to drive change alone. “People have to want to do the right thing,” La Roche said. “This is a way to help reduce impact on climate change, and it’s also a way to make buildings that are better designed.”