It's often commented that modern society is "smart, but not wise," that we know how to do lots of things right, but we don't necessarily do the right things. Green buildings develop from a knowledge base not only of how to make energy-efficient buildings, but how to do so in the least harmful and most resource-efficient way. In their highly influential book, Natural Capitalism, authors Paul Hawken, Amory Lovins and L. Hunter Lovins point out how we've learned to "optimize" each subsystem of a building, but in a way that "pessimizes" the performance of the overall system. In other words, engineers can make a building relatively comfortable with air conditioning and forced ventilation, no matter how poorly the architect has designed the building. That's smart, but is it wise?

My late father-in-law, a mechanical engineer for five decades, lived to be 100; he liked to say that an engineer is "an economist with technical training." In other words, the engineer's goal should be to minimize resource use to accomplish a specific economic purpose, e.g., make buildings healthy, comfortable, productive places to live, work, play and learn. Most engineers have this knowledge or some part of it, but the time-pressured system of building development, design and construction conspires to make most of them into glorified equipment specifiers, not whole-systems building engineers.

Wouldn't it be better to start with the idea of a building that heated and cooled itself because of its orientation to the sun, its use of shading and overhangs, its understanding and use of radiant heating and cooling from the mass of the building itself, its use of natural ventilation solutions to let air move through the building with minimal fan energy, etc. and then (and only then) add the smallest mechanical and electrical systems needed to take care of the remaining demands?

This line of thinking represents the essence of the sustainable design revolution: the use of both traditional "bioclimatic" building designs along with the best of modern systems, controls, materials and technology to develop a new "indigenous" building style for each region. Why shouldn't a building in Tucson resemble a saguaro cactus, exposing the minimal amount of surface area to the sun and the water-draining dry warm air, and one in Portland look more like a tall, majestic Douglas fir, comfortable in its cool, cloudy, wet surroundings?

Arizona buildings ought to be heavy, massive affairs, with radiant-cooled, shaded surfaces and with no direct sun penetration except in winter. In summer the same surfaces would absorb heat from the air during the day and re-radiate it at night to the atmosphere, when no one would be around. They should harvest all of their energy from the abundant sun and conserve whatever water that falls.

Pacific Northwest buildings on the west slope of the Cascades should admit maximum daylight from above, turn a closed north face to the cold winter breezes but admit the low-angle winter light and allow for cross ventilation during the mild spring and fall shoulder seasons. They should recycle all of their abundant rainwater and be able to harvest natural earth energies for both heating and cooling.

Was this article helpful?

0 0

Post a comment