A malfunctioning heating unit produced smoke on the fourth floor of Holman Hall at about 8:30 a.m. Monday.
The malfunction was caused by a power failure, according to a firefighter on the scene.
Students heading to their first classes of the day had a chance to sleep in after the building was evacuated and fans were installed to get rid of the smoke and odor caused by the unit.
Those attending classes on the first and second floors were allowed back into the building a few minutes before 10 a.m.
The rest of the building remained closed until noon to make sure the heating unit did not cause further problems.
In a campus-wide e-mail sent from the office of Facilities Operations, students were advised to contact professors about classes scheduled to take place on the third and fourth floors before noon.
"Students should check with faculty members regarding potential alternative arrangements," the e-mail said.
The e-mail added that all classes normally taking place on the first and second floors of the building would proceed according to schedule.
The Pennington Road, West Trenton and Prospect Heights fire companies reported to the scene after receiving a call at 8:38 a.m.
Myles Ma can be reached at ma5@tcnj.edu.
