Sacramentans driving past Sixth and Q streets might be wondering what the towering building is that resembles a nuclear cooling tower mated with a jungle gym.

If they say it’s “cool,” they’d be on the right track.

The multistory tower is part of the state of California’s rebuilt Central Plant, which provides heating and air conditioning to all 23 state buildings in the city.

“It’s all for heating and cooling the state buildings,” said Project Director Joel Griffith of California’s Department of General Services. “We serve three functions: steam, chilled water and compressed air. It’s all sent through underground piping.”

Most functions are currently on line, but some final tests need to be completed before it fully opens, which Griffith said he expects to be in September.

The previous incarnation of the Central Plant was built in 1962 and needed to be redone - partly for technological reasons and partly because it was designed to dump water into the Sacramento River, and that the heated water was too hot for the river.

Now, the circulated water is cooled in eight cooling towers before it is piped to serve various other uses including watering lawns and operating toilets.

The current design began construction in 2007 and cost about $181 million, Griffith said.

Griffith explained that even though there is some efficiency loss in transporting chilled or heated water through piping to buildings as far away as the Capitol - about two miles of piping - it is far more efficient than using traditional heating and cooling methods for office buildings.

“We get such economy of scale,” Griffith said. “When you have constant usage, you’re much more efficient with a campus system.”

And according to Griffith, the plant was designed with efficiency in mind, and he said he expects it to earn a gold certification from LEED, Leadership in Energy and Environmental Design.

The plant’s tower is for storing the 4.2 million gallons of chilled water that will be cooled overnight so the plant doesn’t stress SMUD’s resources by chilling all that water during peak hours - a plan that saves the state the cost of running the equipment on peak times as well.

The materials used to build the office space are mostly recycled, and numerous technologies were used to ensure the building is “green,” including solar power for some areas, automated light switches, solar shades for the windows and improved air conditioning methods and perimeter heating.

“I’m pretty confident we’re going to get the gold certification,” Griffith said. “We’re using a lot of cutting-edge technology here.”

The plant works by piping chilled and heated water underground to state buildings scattered through Sacramento. At each building, the temperature-controlled water is used to heat or cool air, which is then sent through the ventilation system while the water goes back to the Central Plant.

The compressed air aspect of the facility works in much the same way, with air constantly pressurized in the lines running to the buildings and used to operate various pneumatic machinery, such as air tools.

The project was funded by bonds, which will be paid off over 30 years, Griffith said. The expected life of most of the machinery at the plant is 50 years.

According to Griffith, the savings in electricity costs will come as soon as the water tank is fully operational in September.

“I’m hoping we can move (the) five megawatts (from the plant) from our peak annual usage,” Griffith said. “Our peak usage last year for the plant (campus) was 19 megawatts, so if we shift five megawatts to off-peak times, we will save a bunch of money.”

Aerial photos courtesy Ken Hunt, California Department of General Services.

Brandon Darnell is a staff reporter for The Sacramento Press.