COOPERSVILLE - A mobile classroom mounted on a truck trailer rolled through Michigan recently, showing off environmentally friendly - or green - construction applications for construction workers and the general public.

The "Mobile Classroom of Sustainable Technologies," or shorter yet, the "Mobile Green Classroom," was built in March, appeared at the United Association's Instructor Training Program in Ypsilanti in August, then moved along I-96 to the Lansing area and then to UA Local 174 Coopersville for a week-long visit, Sept.15-19.

The 40-foot trailer, introduced in March, has been all over the country. Its primary sponsors are the United Association of Plumbers, Pipe Fitters and Sprinkler Fitters, and their employer associations: the Mechanical Contractors Association of America and the Mechanical Service Contractors of America.

"This is a great way to teach green awareness, and these are all technologies that are available now," said Jerry Hines, training coordinator for Plumbers, Pipe Fitters and Service Trades Local 704. "I think people look at these applications from different perspectives. Apprentices may look at the piping and mechanical systems, while the general public can learn fairly simple ways to change things around their home that would lessen their impact on the environment, like reducing their use of water."

In addition to apprentices, the trailer hosted high schoolers, college students and even made a stop at the State Capitol.

Among the applications on the trailer:

• A gray water (i.e. water from a sink or shower drain) system that can be used to flush toilets, instead of the use of potable water.
• The use of a dual-handled toilet. Move the handle down for solid waste, and 1.6 gallons of water is flushed into the toilet bowl. Move the handle up for liquid waste, and 0.8 gallons is flushed. Such toilets are on the market now.
• New energy-efficient furnaces with variable speed fans and modulating gas valves that eliminate the "all or nothing" use of natural gas to fire furnaces, allowing for lower amounts of gas to be used on chilly, but not freezing days. "Those furnaces have become a lot more dependable, and they're costing less too," Hines said.
• Tidal generators. Put them in a river and the current rotates them to produce electricity. They're fish friendly.
• Geo-thermal. Heat pumps that take advantage of the earth's constant 52 degree temperatures, combined with a high-efficiency furnace or boiler, combined with lower unit prices and higher dependability - make geo-thermal energy much more attractive these days.
• Wind energy. The wind off of Michigan's lakes makes us an ideal state to do more ind power generation.
• Solar power. Michigan isn't the sunniest state in the nation, but solar power does have a limited place in the electric grid.
• The use of hydrogen fuel cells. NASA uses them in space, but they're still not quite ready for the mass market.
• Aerobic and anaerobic digesters. It's a technology that's still in its infancy, but an anaerobic system is running in Manistee. How does one work? Combine biological waste material, introduce bacteria in a controlled environment, and voila, methane gas is produced and can be burned to produce electricity.

Hines said some of those applications are farther along than others when it comes to whether the building trades will be installing them anytime soon.

"It's a pretty cool trailer," said Local 174 second-year apprentice Micah Gulba. "Some of the piping is familiar, some of it isn't, but it looks like something we can do."

Al Balcam, who teaches green awareness at Local 174, said the trailer "makes people think, and it also shows the public what our people in organized labor do, and what we're all about." He said green construction "isn't a fad - the public is becoming much more accepting to it."

The promotion of regulations governing green construction such as the LEED Standard, have moved green construction more mainstream. "The green future is here," said Charles Lockwood, in a 2006 article for the Harvard Business Review. "Like the dramatic, occasionally unsettling, and ultimately beneficial transformations wrought by the introduction of electric lights, telephones, elevators, and air-conditioning, green building principles are changing how we construct and use our workplaces, as well as our homes, schools, stores, medical facilities, and civic and cultural institutions."

LOCAL 174 APPRENTICES watch a demonstration of "green" technology in the Mobile Green Classroom in the parking lot of their union hall.