Toward that end, architects, college faculty, state employees and University of Hawai'i students gathered last summer to create portable designs for the state Department of Education that are cool, ecologically supportive and conducive to learning.

The group is running its top two designs through a computer simulation program to see how well they disperse heat. They expect to turn over the final plans to the state next month.

An average of 20 to 25 new portables are added every year at a cost of between $3 million and $4 million, said Ray Minami, facilities director for the state Department of Education.

Chad Okinaka, a member of American Institute of Architects, Honolulu Committee on the Environment, said the continued need and the flaws in some older portables led the group to find a solution.

"The conditions are just crazy," Okinaka said. "Whether it is the humidity levels or the carbon dioxide levels or the heat, 90 degrees at 90 percent humidity and it is only 11 in the morning — how do you teach in that environment? From the AIA standpoint, we have a responsibility to try and help where we can."

A research team led by the UH School of Architecture monitored portables in Wai'anae, Kaimuki and Koko Head. Its report concludes that retrofitting the existing portable classrooms would be too expensive and adding air conditioning is not practical because they were not built airtight. They need to be replaced.

"The conditions that these students are enduring are conditions that most adults would not tolerate in their workplace," according to the report. "These conditions are beyond acceptable standards."

Duane Y. Kashiwai, chief of the design branch for the state Department of Accounting and General Services, said portables have evolved over the years and many newer ones now have double wall construction and air conditioning that make them much more comfortable, but he welcomes the new designs.

"If we see that UH has come up with something that is constructible and falls within the same-cost ballpark, we would like to take a look at that," Kashiwai said. "We would like to improve the quality of the buildings."

Okinaka said two new designs will be offered, one with the standard dimensions of a typical portable and the other a modular style that can be enlarged or reduced in size as needed. Both will incorporate a solar chimney.

A thermal chimney works as a natural draft device that uses solar radiation to move air upward, thus converting thermal (heat) energy into kinetic (motion) energy. The system would save energy by not using air conditioning to keep students cool.

"The concept is the sun hits the roof and heats it up and then you get a temperature differential between the inside and the outside," Okinaka said. "You use that so the hot air will rise up into the ceiling and out."

The designs will also include better use of day lighting, flexible interior space for different classroom configurations and a plan for how portables can be clustered together to make better use of the environment. The cost should be on par with current construction costs, he said.

"They are called portables, but they are actually not because they hardly ever move once they put them down," Okinaka said. "The design is meant to take advantage of the sun, both for day lighting and to drive the solar chimney, and the orientation ... to raise the comfort level for the students and teachers. I think it is a good project and I really hope it gets to be a reality."

Mike Fox, president of Hawai'i Modular Space Inc., supplies the DOE with 10 to 15 portable buildings a year. Fox said portables today are sturdy and well-designed and the principals are happy with their product.

Fox said if the DOE accepts new plans for portables, the Mainland manufacturer should be able to easily use them.

"From what I know of green design, I don't see any big major hurdles," Fox said. "Without seeing the final design, it's impossible for me to say absolutely we could do it, but from what I know of green architecture and from what I've seen out there, it would not be a problem."

Fox said it is likely that the cost would go up or down depending on the specifications.

"It could also remain the same, but whenever you change the design or specifications, the numbers have a tendency to move one way or the other," he said.

Meanwhile, Rep. Maile Shimabukuro, D-45th (Wai'anae, Makaha, Makua), is leading a campaign in Wai'anae, where older portables are in use, to have people donate fans, which are installed to give some relief to the students.

"Whenever you talk to the principals they say the portables are like ovens," said Shimabukuro. "For some reason, the way they are designed, they are the worst of the worst of the classroom spaces."

After fans were installed in her portable classroom at Leihoku Elementary School, third-grader Kawehionalani Lau saw a big difference.

"The fans have helped us to be cooler in class," Lau said in a letter thanking Shimabukuro. "We used to sweat so much because of the weather and heat that some of my classmates got their paper stuck to their arms."

The use of portable classroom buildings goes back to the 1960s, according to Ray Minami, facilities director for the DOE.

Minami said there are now 1,430 portables in use across the state with a total of 1.2 million square feet of floor space. By comparison, Ala Moana Center has 1.8 million square feet of space.

Minami said the need for portable classrooms is most acute in Central and Leeward O'ahu and parts of Maui and the Big Island where communities are growing.