With the clock ticking toward school reopening, Philadelphia School District leaders Tuesday attempted to quell criticism of its plans to ventilate its old buildings by adding window fans to 1,100 rooms citywide.

Chief operating officer Reggie McNeil said the district has been “putting a lot of work into making the environment safe enough for our students and staff to return.” Prekindergarten through second grade staff are due back Monday, and children on Feb 22.

The news conference was called after pictures of the fans — in some cases the same sort of window units you would buy for your home at a big-box store — circulated widely, raising alarm in teachers and parents.

» READ MORE: Will Philly’s third attempt at school reopening stick? Teachers are wary and parents are split.

“I think it’s appalling the district would think this is the answer,” said Samantha Rutherford, a kindergarten teacher at Bethune Elementary in North Philadelphia. “It is very terrifying.”

It’s a problem most school systems simply don’t have: If rooms lack adequate ventilation, they fix the issue.

In wealthy Lower Merion, the school system said its classrooms met ventilation standards pre-pandemic, but it upgraded ventilation and filtration systems, just in case. In the Eastern Regional School District, in Camden County, most classrooms lack air-conditioning, but the school system is trying out ceiling fans that create upward air flow and have special UV lighting to disinfect possible pathogens. Eastern Superintendent Robert Cloutier said fans were considered in the fall, but “at the time, there was no clear information on whether it was safe to use traditional room fans.”

For the cash-strapped city school system, some buildings are more than 100 years old and decades of delayed maintenance means the fixes open to wealthier districts aren’t always possible.

In Philadelphia, the fan issue crystallizes a deep distrust teachers and many parents have of the school system, especially around buildings: This is the district that let environmental hazards like lead paint and asbestos linger for years, and just last year bungled a $50 million construction project at Benjamin Franklin High School that sickened students and staff and kept students out of school for more than a month.

Superintendent William R. Hite Jr. has repeatedly assured teachers and parents that any rooms used when schools reopen will be safe. Just last week, he told the school board the district’s 3,000 fans would have regulators on them to ensure that airflow requirements were being met.

But on Monday night, Hite said there were actually no gauges. In an email to staff, he said he made “an honest mistake.”

“Instead, each fan has the amount of air flow it generates in the manufacturer’s data,” Hite wrote. “We have taken the extra precaution of measuring the airflow of the fans with an air balancer to ensure that the manufacturer’s data is accurate.” He said ventilation “continues to be one of the layers of safety that will be in place in all of our school district buildings as we prepare to slowly and safely return to in-person learning.”

McNeil said at the news conference Tuesday that the district has fixed airflow units in a few schools, canceling the need for fans, but that about 1,100 rooms citywide still require the fans. About 37% of the fans are installed, and the goal is for all to be in place Monday, when teachers are due back.

McNeil said that building engineers will be responsible for monitoring temperatures, and that in spot testing rooms with known temperature issues, none had dropped below 68 degrees, the district-set minimum temperature.

Fans will bring in fresh but not filtered air; McNeil said the district is looking at potentially adding air purifiers to some rooms, but has no immediate deployment plan. And while upgrading ventilation systems wholesale would be desirable, the district’s size and finances simply don’t allow that.

“We have to work with what we have,” McNeil said.

Jerry Roseman, the teachers’ union’s environmental scientist, has seen the fans and knows the schools’ ventilation systems intimately.

“The use of the fans selected by the district is not a best practice in the school situation,” said Roseman, who has 35 years’ experience in the field. And the 15 cubic foot per minute of airflow the district pledges the fans will deliver “is not a standard or a control to undercut pathogens.”

Yes, the fans will introduce fresh air into rooms that lack it.

But they’re problematic, said Roseman: The fans will require blow-in air that’s too cold in winter months, bring in dust and dirt, and blow particles from person to person in a direct air stream — a danger in a pandemic. District workers have placed grates in front of them, which will hamper the fans’ ability to provide the air volume and distribution needed to mitigate the virus.

“I don’t feel confident that these schools are safe in the way they’re being claimed,” Roseman said. The Philadelphia Federation of Teachers has a memorandum of understanding with the district that sets certain standards for reopening, and PFT president Jerry Jordan has said he does not yet have the data he needs to say schools will be safe.

Both Mayor Jim Kenney and Thomas Farley, the city’s health commissioner, addressed the fan issue at a news conference Tuesday.

Farley said he thought the fans were “a good idea,” and Kenney said they were “a simple solution or a simple way to address the problem.”

In Chicago, teachers have refused to report to work over building-condition fears, blocking a reopening. A strike is possible. The PFT has said it won’t speculate on whether such action is possible in Philadelphia, but the Caucus of Working Educators, an activist group within the union, has said it will back any school employee who does not report because of safety conditions.

Teresa Kelley Rugerio, a teacher at Elkin Elementary in Kensington, works in a school that last year alone had “damaged asbestos, filthy air filters, unregulated temperatures causing extremely hot classrooms, mouse infestations, and raw sewage standing outside the art room and main entrance to the school for four days,” she said. That the district plans to use fans to address ventilation issues to mitigate COVID-19 risk is simply unacceptable, Kelley Rugerio said.

“I feel like there’s a lack of trust because of mismanaging over years and years of letting schools be in disrepair and making assurances that are not true,” she said.

Staff writer Laura McCrystal contributed to this article.

The Philadelphia Inquirer is one of more than 20 news organizations producing Broke in Philly, a collaborative reporting project on solutions to poverty and the city’s push toward economic justice. See all of our reporting at brokeinphilly.org.