A big part of green design is how we use energy. It’s now possible to collect all the energy we need for buildings from renewable clean sources like solar, wind, geothermal, and from streams and rivers. In graphics design, our first step to heat or cool a building is to consider the exterior color. Dark colors absorb the sun’s energy, making buildings hotter, while light colors reflect the sun’s heat, keeping the building cooler. Therefore, public buildings that normally have a lot of people heating them up usually need cooling, so therefore should be light colored, while residences more often do better with darker exteriors. Our strategy usually is to first consider building colors, then incorporates the greenhouse effect (heat build-up through the windows), and finally by using collectors to heat air or water. We use floors and walls of concrete and masonry, and sometimes volumes of water in tanks, to store the heat so it can be used later. For insulation, we like spray foam. This rigid material is sprayed as a liquid from a gun into crevices and framing spaces.
Our Cooling Strategy
For cooling, in addition to light colors, we prefer simple ventilation, something of a lost art nowadays. Designing thoughtfully for good airflow works in mild climates, like we have in much California. Shade trees help too. We like “cool tubes”, which are lengths of buried plastic pipe, with fans that blow in outside air. Buried eight or ten feet underground, where the soil temperature is consistently cool year-round, the air existing the tubes, into the building, can be up to 10 degrees lower than it was outdoors.
Our Heating Strategy
We also use geothermal systems, usually in the form of buried pipes with loops of hose through water is pumped. Together with heat pumps, which are electric devices that use the temperature differential between the earth and the atmosphere for both heating and cooling, these systems are usually cheaper to operate than central heating or air conditioning.
Most people are familiar with photovoltaic (PV) solar collectors, those dark glass panels that convert sunlight into electricity. We use PV on most of our jobs, as well as other types of panels. Hot water collectors often find their way into our projects. These are simple shallow black boxes with glass faces, normally about 4 feet by 8 feet in size. Inside the boxes are long loops of black rubber hose not unlike that found in your garden. As water flows through the hose, it is heated because of the greenhouse effect inside the collector.
People lucky enough to live next to a river or even a large stream may be able to install a small turbine in the water flow, to turn a generator to create electricity for a home. Wind generators (windmills), have come a long way and now can be seen with some very interesting designs, however, are only cost-effective if there is strong wind for a significant part of the day.