The old window air-conditioning unit inside Amanda Quinteros’s two-bedroom apartment provides welcome relief from the summer heat. But to use it, she and her husband must pay their landlord an extra $75 a month.

The charge is illegal, according to a lawsuit filed Wednesday in Fairfax County Circuit Court against JBG Residential Services LLC, the property management company at the Olde Salem Village Apartment Homes in the Baileys Crossroads section of the county.

The suit alleges that the charge violates language in tenants’ ­leases that stipulate fees for electricity and water but say nothing about air conditioning. The suit also alleges that the fee violates a Virginia housing law that prohibits landlords from charging more for a utility service than what that service costs to provide.

“Right now, we’re bearing the heat because the one air conditioner is all we can afford,” Quinteros, 51, a plaintiff in the lawsuit, said as her grandson and neighbors’ children played near the cool air streaming from the unit. “We don’t use the other one we have, because they’ll charge us.”

The suit seeks damages and an injunction against the fees at the 448-unit complex, where rent for a two-bedroom apartment starts at $1,365.

The complex’s “Air Conditioner Policy” is outlined in a memorandum given to tenants every spring, the lawsuit states. Tenants are required to pay $325 per air conditioner for April through September or $75 for each month an air-conditioning unit is used.

Listed as an “amenity fee,” the charge is explained as a way for JBG staff to monitor the air-conditioning units to ensure that they meet aesthetic standards, attorneys for the tenants said. JBG employees check apartments to see whether air conditioners are in use, tenants said, and assess fees if they have not already been paid.

Officials at JBG, which manages 7,500 apartments at properties across the Washington region, did not respond to questions about the fees or the lawsuit, but they said the company is in compliance with its leases and state regulations.

“As with all of our communities, JBG is committed to ensuring that our residents are proud to call our community their home,” company spokesman Matthew Blocher said in an e-mail.

The suit alleges that the air-conditioning charges at the Olde Salem Village complex increase incrementally each year. If the fees are not paid on time, the amount the tenants owe is doubled, said Simon Sandoval-
Moshenberg, a lawyer at the Legal Aid Justice Center in Falls Church, which is coordinating the lawsuit on behalf of the mostly Latino tenants in conjunction with the D.C.-based law firm Quinn Emanuel Urquhart & Sullivan.

“It’s just nickel-and-diming them for everything,” Sandoval-Moshenberg said.

Lauren Boston, a spokeswoman for the National Apartment Association, an Arlington-based industry group for owners of large apartment complexes, said she was unaware of air-conditioner fees in other buildings.

“Nobody here has heard of that kind of charge,” she said. “But we’d have to do more research to know for sure.”

The fight over the fees has been brewing for several years at Olde Salem Village, off Leesburg Pike. Community organizers have sued JBG on behalf of individual tenants at least three times in recent years, but those cases focused on specific disputes rather than whether the fees should be allowed.

In one case in 2013, a Fairfax County judge ordered JBG to return $135.50 to a tenant who was incorrectly charged a late fee for using his air conditioner, court records show.

The Olde Salem complex is portrayed on its Web site as a tranquil haven for young professionals.

But tenants say that neighborhood crime has caused police to be a regular presence in the area and that rodents and cockroaches are a problem in some apartments. In general, the complex is considered to be well managed, county officials said, but records show that inspectors have visited the complex and found cases of bed bugs.

Everth Romero, another plaintiff in the lawsuit, pays $150 a month for two air conditioners in the bedrooms of the apartment he shares with his wife and young son, but he keeps the living-room window open to circulate air there.

The third-floor apartment tends to bake in the summer heat, he said. In July, when he was late with the payment, he was charged a $157 penalty.

“I can’t keep paying all this money,” said Romero, 32, who is unemployed after he was injured a year ago at his construction job. The family relies on the roughly $525 per week his wife makes cleaning houses, he said, and plans to move when their 15-month lease expires in November.

With median rents in Fairfax County hovering around $1,500 per month, the complex remains a relatively good deal even with the extra fees, community organizers say. For that reason — and in some cases because of immigration status — many residents have been reluctant to complain publicly.

“Nobody wants to say anything, out of fear of being thrown out,” Quinteros said.

Quinteros said she raises the money to pay for her air conditioner by babysitting neighbors’ children and selling El Salvadoran tamales, steamed to perfection inside her tiny kitchen. She charges a dollar per tamale.

“People have said I should charge more,” she said over the whir of her window unit. “Maybe $1.25.”