By George F. Lee, Star-Bulletin
A ventilation turbine sits on the teacher's desk
in a Waianae High portable classroom that is being
remodeled to make it cooler.
Cooling off
Now that there's a hole in the roof,
By Burl Burlingame
the temperature's dropping in PO239
Star-BulletinTeacher Ryan Oshita stood on a stepladder, picked his spot, and drilled a hole through the wooden ceiling, through the tar paper, mastic and gravel, and out into the open air. There was no turning back now. A tiny sliver of sunlight leaked into Portable Classroom No. P0239, and hot air, buoyed by excited molecules, began to rise and vent through the hole.
After more than a year of experimentation, analysis, testing, reporting and recommendations, the "Waianae Solution," a way of cooling hot portable classrooms easily and inexpensively, became a reality on Saturday. Students, teachers, administrators and interested parents gathered at Waianae High School to convert a portable.
During the experiment, Waianae science students, under teacher Naidah Gamurot, built large scale models of a typical portable and ran exhaustive tests. Their analysis: The portables are poorly ventilated and insulated, and hot air is trapped inside. They then brainstormed and tested solutions on the models. In the process, the kids learned about physics, architecture and technology, and gained an appreciation of how they can make a difference in their school and community.
The best solution: Using convection, the natural ability of hot air to rise, hot air can be channeled out of the building if a release point is located near the roof's apex. If a layer of reflective insulation is added beneath the roof and a source of cool air is added, a kind of thermal engine is created. As hot air trapped in the "attic" escapes, cool air is sucked in from under the building via PVC pipes.
All experimental data showed that this would work. The next trick was getting the state's Department of Accounting and General Services to agree to converting a portable for test purposes. This took some time, but in the process, publicity on the project led to increased public awareness of the heat problem in children's classrooms.
By George F. Lee, Star-Bulletin
Ray Sumile is among a crew of volunteers helping to
modify a Waianae High classroom to make it cooler. Here
he adjusts strings that will level an aluminum frame
holding a false ceiling. The ceiling will disguise reflective
material and air vents that will force hot air
out of the portable classroom.
The solar-power industry, through R&R Solar Supply, donated 14 photovoltaic-cell-powered roof vents -- seven by Sun Vent, seven by Cyclone, each worth about $330 -- to the Department of Education for testing in portables. They were installed during Christmas break in portables around the state, including Waianae, said DAGS controller Sam Callejo. Hawaiian Electric is also testing a solar-powered light system on a Waianae portable.The solar-cooled classroom at Waianae is two doors down from the Solution Test Portable, and the portable in between, with no changes at all, will be the control unit. "Unfortunately -- actually, fortunately! -- it's been pretty cool out here this last month," said principal Hazel Sumile. "But that means it's been hard to see any kind of dramatic difference."
Dipping into the school's discretionary fund for $1,200, materials were assembled to convert the classroom. The original plan to suspend aluminum-foil coated bubblewrap -- which reflects more than 90 percent of the heat -- was modified to include a false drop-ceiling in the classroom. This was more expensive, but also will look a lot nicer.
Good intentions aside, the next trick was actually solving the Solution. For advice, principal Sumile needed to look no farther than husband Ray Sumile, an engineer with Hawaiian Tel. Sumile, Oshita, science teachers Gamurot and Ric Gresia, and school-to-work coordinator Ben Yamada stood around in the classroom for awhile, holding up lengths of aluminum T-channel and measuring everything. "So many chiefs, too many cooks!" laughed Ray Sumile. "This will take us a month to figure out!"
Where to put the vent? "This one is up to you, Naidah," said Ray Sumile, and Gamurot sat down in a chair to consider. She pointed near the center of the room.
The vent -- which is what Oshita center-marked with his drilled hole -- is a standard industrial turbine vent with a large base. They worried that the large hole would weaken the tongue-and-groove roof, and so the hole was framed with two-by-fours.
As the adults hung the framework for the false ceiling, the kids cut the reflective bubblewrap to fit the drop-ceiling panels. the panels should block air enough to create a closed environment in the false attic airspace.
"Those kids are really moving along," marveled Ray Sumile.
The wooden window louvers, however, stick up into the space. Oshita suggested a simple solution: drill out one of the retaining rivets on each louver, and the louver will be disconnected from the rest, and can be sealed in place.
They got the job about half-completed Saturday, and will finish it off in the next week. Ray Sumile estimates that, once this experience is behind them and the supplies are standardized, two or three workers could easily convert a portable classroom inside a day.
And then we'll hope for a week or so of really miserably hot weather to gather more real-world data. Stay tuned.
"But I'll tell you," said Ray Sumile. "Once that hole was opened in the roof, and the hot air had a place to get out, people started saying they could tell the difference."
The Waianae Solution
This real-world science project was instituted by the Honolulu Star-Bulletin more than a year ago as a project for Waianae High students:
The question: Why are the portable classrooms used by the Department of Education so stifling in hot weather?
Project Portable back issues
