Gov. David Ige’s campaign to cool 1,000 classrooms exceeded its goal in September 2017, but some of those systems, powered by electricity from the sun, are already on the fritz.

And plenty of public school classrooms never got cooled. Just over half, or 6,200, of the 11,000 classrooms statewide have air conditioning.

As the summer heat keeps breaking records and some students sit in sweltering conditions, the Department of Education is taking a new tack. It has streamlined the process so schools can easily install energy- efficient window units that are much cheaper to buy and maintain than the split-system, photovoltaic AC put in two years ago.

Corey Rosenlee, president of the Hawaii State Teachers Association, sees the new policy as a major breakthrough because the costs will be low enough to reach many more classrooms.

“I think this is huge,” he said Thursday in an interview. “This means thousands of classrooms will be able to get AC now, and tens of thousands of kids can be impacted. It’s a real game changer as to how we air-condition Hawaii’s schools. We’re really excited.”

Only energy-efficient window units that are suited to classrooms may be used, and only on buildings with electrical capacity. But the electrical load at most schools has been lightened in recent years with major moves to improve energy efficiency.

The department, for example, has swapped out 700,000 light bulbs at all Oahu schools with high- efficiency LED bulbs, and more than half of neighbor island schools.

In 2016 legislators set aside $100 million in an emergency appropriation for air conditioning, heat abatement and energy efficiency at public schools. In order to avoid pushing up electricity demand, the department opted for split- system air conditioners relying on solar power, a forward-thinking but pricey approach.

Altogether, 1,300 classrooms statewide got AC through that appropriation. The money also went to heat abatement, including ceiling fans, nighttime ventilation, painting roofs with heat-reflective coating and extending shade.

While most of the solar- powered air conditioners are still working fine, some have run into problems. The systems were designed to keep classrooms comfortable, not cold, for a five-hour window each day. But some users came in early, cranked them on and turned the thermostat down low, exhausting the capacity of the photovoltaic batteries.

“What we learned is that what the systems were designed to do didn’t meet the expectations of the user,” said John Chung, public works administrator for the Department of Education. “If you drain the batteries too far, sometimes they won’t come back. It’s a vicious cycle.”

The department has been responding to complaints and doesn’t have an overall picture of how many of the new systems are problematic, Chung said. But the problems seem clustered on Maui.

“On the other islands, the PV systems are tied to the electrical grid, so every night they’ll charge up batteries,” he said. “The Maui systems weren’t done that way for a number of different reasons. Part of our solutions is to connect all of their systems to the grid.”

The push to cool so many classrooms on short order required the use of numerous suppliers, and vendor performance varied, so problems vary from campus to campus, he said. The department has put out a request for proposals for a repair contract for the systems, using operating and maintenance funds.

“It’s worth $700,000, so we don’t know how far that’s going to take us,” Chung said.

To speed up the installation of window units, the department is offering to send out teams to do electrical assessments of campuses and identify buildings that can handle window air conditioners. So far, 40 schools have taken advantage of that.

Principals can then take the baton and run with it, partnering with community supporters, businesses, PTAs and legislators to fund AC units. In the past the principals had to hire electricians for those assessments and get approvals from multiple state offices to accept donations.

At Lanakila Elementary, kindergarten teacher Janice Nii remembers how hot and sticky it got last year in her classroom with no air conditioning.

“It was miserable,” she said Tuesday. “It’s very difficult for the children to concentrate, to succeed.”

This year her brightly decorated kindergarten classroom is not only visually attractive, it is invitingly cool, with two new AC units installed through the new School Directed AC program.

“With AC, not only do we get the room temperature comfortable, the acoustics make a drastic difference,” she said. “The children can concentrate better, listen to the teacher. For me, if my children are happy, I’m happy. It’s an all-around win-win situation.”

A few of her former students drop by her kindergarten room after school to help her with filing and other class preparation. It’s not just altruism. Asked why, third grader Christian Rabutan piped up: “Because there’s AC!”

“Everybody in my class gets tired because it’s so hot,” he said. The third grade classrooms don’t yet have AC.

So far, 200 window air conditioners are in or on the way to 52 schools through the Schools Directed AC effort, according to Lindsay Chambers, communications director for the DOE.

Classroom air conditioners require more fresh air intake to accommodate the large number of people inside, compared with residential units. The department recommends 2-ton (24,000 BTU/h) AC units. (A ton is a measure of cooling capacity.)

Two such units two are needed for a typical 900-square-foot classroom, according to DOE. Each unit costs about $1,600; with the costs of installation, including a licensed electrician, the total comes to about $8,000, according to HSTA. But units and labor can be donated.

“I’m hoping within the next couple of years that most, if not all, of our hot classrooms are finally air-conditioned in Hawaii,” he said.

HELP YOUR SCHOOL

If you’d like to donate funds or an air conditioner to a public school, contact the principal first. AC units must meet energy and safety requirements and be installed by a licensed electrician. Classroom air conditioners require fresh air intake given the number of people in the room.

Recommended equipment:

>> Capacity: 2-ton (24,000 BTU/h) units (A ton is a measure of cooling capacity.)

>> Dual inverter or commercial-grade

>> Energy Star-certified