The owner had previously tried to remove it, but was unable. However, the efforts loosened the air conditioner.
The unit bounced off the awning of the Wine Bar restaurant, and landed on the street.
A man with his dog was either hit by the falling awning or when the air conditioner bounced off it.
Anthony Franzese, 70, was taken to Bellevue Hospital to be checked out.
He was listed in stable condition with what police said was a minor head injury.
Neighbors said Franzese frequently sat below the awning to have a glass of wine.
Police said the incident was an accident and no charges would be filed.