High Desert Facility Is an Energy Model

Now that the flame-colored wildflowers are gone, the best thing about the Antelope Valley Poppy Reserve may be its visitor center.

Closed to the public since the brief poppy season ended in May, the long, low building all but disappears into the undulating hillside behind it, in the 1,745-acre park 15 miles west of Lancaster.

But belying its modest appearance, the squat building is an architectural marvel--a structure so energy-efficient that it requires neither air conditioner nor furnace despite desert temperatures that swing from 110 degrees in summer to below freezing in winter.

Bill Verdery, maintenance chief for the seven Mojave Desert parks run by the California Department of Parks and Recreation, points with pride at the structure--proof, for 20 years now, that building smart pays off in the long run.

“It was designed during the first energy crisis,” Verdery said of the 2,100-square-foot center, built not long after Americans experienced endless lines at gas stations in the 1970s. Exploiting the desert’s abundance of solar energy, the building uses simple but ingenious design and technology to provide heat, cooling, lighting and warm water for the restrooms.

“It’s all passive, and once it’s built, it’s energy-efficient forever,” said Verdery, 49.

Because conservation is built in, the expense of keeping the building at a comfortable temperature is reduced to the cost of running a fan--90% less than cooling and heating a comparable building, Verdery estimated.

Style Reflects Site’s Native American Roots

Viewed as you drive up the winding entrance road to the park, the center looks like a long, fuzzy Navajo hogan. Its style reflects the site, the ancestral desert home of half a dozen Native American tribes in an area that once served as a major trade route between the Indians of the Southwest and those on the Pacific Coast.

If the building seems to grow out of the arid site, it also cleverly exploits it to save energy. San Francisco architect Robert D. Colyer began designing the building, with partner S. Pearl Freeman, in 1980. “It was the first building my newly formed firm designed,” Colyer said.

Built for $450,000 and dedicated in 1982, the building was commissioned by the parks department, which urged the young firm to be innovative and use as many alternative-energy features as possible.

Colyer, 51, said he was inspired by the poppy reserve’s rolling buttes and distant mountains. “It really presented us with a very poetic environment to work in,” he said.

Colyer, who was trained at the Georgia Institute of Technology, said he and his partner used the latest technology in designing the building.

A sophisticated computer program allowed them to predict its “thermal performance,” and they were able to feed weather data from nearby Edwards Air Force Base into the computer to see how the building would heat up or cool down, depending on design features and the changing weather. “Gee,” he said, recalling a simulation during the process, “it’s overheating during September. Let’s make a few changes.”

Armed with the design plans, the first thing the construction crew did was dig deep into the hill, carving out a space in which to tuck the building.

As a result, the hill now hugs the visitor center on three sides. Even the roof is covered with two feet of earth and a scraggly lawn.

The purpose of all that dirt, Verdery explained, is insulation. Plastic sheeting and a layer of Styrofoam under the soil boost the insulating ability even more.

The front wall, which faces south, is mostly glass, and it is here that the building reveals how effectively it was designed. As Verdery explained, a simple overhang limits how much sunlight--and heat--enters the building in summer when the sun is high in the sky. In winter, when the sun is lower, it shines directly into the building onto the masonry floor, which retains heat and slowly releases it back into the structure.

If the center gets too hot, fiberglass shades on the outside and interior shades made of an insulating mix of cotton and Mylar can be pulled down to keep out the sun. “Two years ago, we began replacing the curtains,” said Verdery, pointing to one of the original interior shades--white to deflect heat.

Unique Passive Cooling System

Instead of standard air conditioning, the building has a unique passive cooling system. It was inspired, Colyer said, by an ancient Persian technique for cooling buildings. Medieval Persian architects built towers that scooped up the desert wind and drove it down into deep wells where it was cooled and humidified, then fed into homes.

The Antelope Valley version employs an “earth tube,” a metal pipe with a 3-foot diameter, bent like a periscope, that sits on the hill above and behind the visitor center.

At night, cool air enters the building through the tube, buried 10 feet deep in the ground, where the temperature stays around 70 degrees. Meanwhile, hot air inside the building rises and escapes through a convection tower on one end, pulling more cool air in through the earth tube.

Located side by side, the center’s restrooms are as homely as most public restrooms, but a lot more energy-efficient. On the front, facing south, each has a so-called trombe wall.

As Verdery explained, these consist of glass in front of a masonry wall that has been painted black. The black surface absorbs heat, which slowly radiates out into the restrooms. The trombe walls can keep the restrooms comfortably warm in winter even if the sun doesn’t shine for two or three days.

The building’s water is heated by the so-called breadbox heater on the roof. Sunlight passes through the breadbox’s glass skylights and heats water in a tank, painted black.

This heater produces lukewarm water, not hot enough for such home uses as doing dishes or bathing, but adequate for its primary purpose at the center, washing visitors’ hands, Verdery said.

While the award-winning Antelope Valley visitor center is the parks department’s energy-saving showcase, it isn’t its only conservation-minded facility.

“For years and years, state parks has used solar panels along the beach to heat showers,” Verdery said.

As for the visitor center at the poppy reserve, it holds a first-born’s special place in the hearts of the pair who designed it. “We go back every few years or so just to look at it,” Colyer said.