After being forced to deal with rats, cracked foundations, and construction noise at all hours of the day, residents of the area on West 13th Street near the Metropolitan Transportation Authority’s “big dig” are dreading the grand finale: A 100-hour test of the five 6-foot fans being installed in the street.

Those who live near the construction site have watched with disbelief as the deadline for completion of the emergency ventilation system for the subway tunnels has been pushed back by months. Transit authority officials said the delay came after the discovery that the fans wouldn’t be adequately powered without additional construction that wasn’t part of the original plan.

The 100-hour test will be divided into 10-hour segments over 10 days, a Transit Authority spokesman, James Anyansi, said. One resident said she feared the noise and vibration from the fans would be unbearable.

“I heard the decibel level is going to be so high that people might want to leave,” a neighbor of the site, Randy Jenkins, said. She said she is afraid to walk her dog outside next to the fans when they are running.

Once the test is completed the fans will not run except for circumstances when the MTA needs to pump air out of or into the tunnels, such as a fire or a situation with noxious gases. The fans will service the section of the tunnels between the West 4th Street and 34th Street stations.

Residents don’t deny the fans are a necessary addition to the transit system. A smoky fire in a storage room closed down the 4th Street Station and part of Sixth Avenue last October. All trains were diverted from the major transit hub for hours. With the new fans in place, smoke from such a fire would be pushed out of the tunnels.

Mr. Anyansi said the noise was expected to be minimal based on previous tests in other neighborhoods. He said the authority is even considering running the test for 100 hours straight if it isn’t too loud. Although there is no final date for the project, he said the fans were expected to be started up for the series of tests at the end of December. There will be a two-hour test and a five-hour test before the marathon 100-hour test, he said.

At a meeting on Tuesday night with the project’s engineers, some residents were angry. One man asked why the smoke and noxious gases from the subway tunnels had to be blown onto their street. Another resident demanded a final completion date, but the MTA officials could only say they expected to end construction by the end of June.

The chairman of Community Board 2’s Traffic and Transportation Committee, Brad Hoylman, said the MTA had improved as far as at least listening to the community.

“They have done a good job lately in keeping lines of communication open with the community, but there have been many delays with the project,” he said.

The committee will be hosting another open forum with the MTA May 9. If the fans are too loud, they will call another meeting, he said.

The president of the Upper West 13th Street Block Association, Sonja Alaimo, said things would be far worse if the tests showed the fans didn’t work, which would mean more construction.

“We’ve gone through a lot,” she said. “They’ve spent over $25 million. Hopefully the fans will survive the tests.”