At 11:30 Saturday night when it was 82 degrees outside, Sinclaire Wylie was sweating in 92-degree temperatures inside her efficency apartment in a high-rise public housing project for the elderly downtown. Two fans whirred uselessly nearby, throwing out blasts of hot muggy air.

Wylie was one of more than 500 senior citizens in three city-owned public housing developments who spent the weekend in furnace-like temperatures bereft of air-conditioning because the cooling systems in their buildings had broken down.

Wylie's building, the 10-story, 343-unit Claridge Towers at 12th and M streets NW., was still without air-conditioning yesterday, an amenity residents have lacked for more than a month.

Also, the tenants at the 228-unit Garfield Terrace, at 11th Street and Florida Avenue NW., roasted this weekend because their brand-new system broke down Thursday. It had been turned on just the preceeding day after being turned off for two weeks because of an eariler mechaincal failure. By late yesterday, it was again working.

Ten apartments at the 271-unit Judiciary House, another senior citizen project at 461 H St. NW, also went without air-conditioning throughout the weekend.

While Claridge residents have been plagued with air-conditioner breakdowns off and on since the city government installed the system in 1969, this has been the worst year, said Wylie, president of the residents' council.

"This is inhuman," said Lilly Varlos, 58, as she paced nervously in her apartment wiping away the perspiration Saturday. "I spend 24 hours a day here. Where would I go out? I was robbed seven times (in the hallways and in her apartment)."

"It's terrible when these apartments get hot," said Dorothy Johnson president of the Garfield residents' council. "The bedrooms are on the front like the living rooms so the people don't have anywhere to run." She said many of the elderly residents suffer from respitory and heart problems that are aggravated by the heat.

The city suffered through three days last weekend with temperatures in the upper 90s, the hottest spell in several years.

Richard Storman, acting chief of maintenance for the city's 12,000 public housing units, said he did not understand why the private firm hired by the city to maintain the cooling ststems in most of the elderly buildings had failed to repair the Claridge system.

Frank Russell of Acmat, the private company, said the problem was with the complicated Claridge system that requires keeping the heat in the building's boilers at 250 degrees and then running the heat through a briny mixture to cool it. The boiler peridocally falls below 250 degrees, he said, making the system malfunction.

"It's a headache," he said. As for Garfield, he said, since that is a new system the manufacturer, not Acmat, is responsible for its maintenance until the warrenty expires.

"People are entitled to have air-conditioning," said Lorraine Washington, the Claridge manager. "How would you feel if you had a heart condition and no air-conditioning?"

Washington's office and an adjacent medical clinic are cooled by a different system from the one for the tenants' apartments. Hers worked throughout the spring this year, and Washington said she peridoically invited tenants into her office when the main building system failed.

During last weekend's heat spell, however, her office was closed. The air-conditioning remained on, and frustrated tenants loitering outside in the hope of finding a breeze could see the windows of the office frosty with cold air.

One of those seeking relief was Roberto Wallace, 52, who said he had lost 15 pounds in the last two weeks. He said he just sweated it off in the heat of his apartment where a thermometer registered 92 degrees Saturday night.