At 17:47 hrs. units from Kent Island VFD and Grasonville VFD were alerted for an odor inside of the Dollar Tree in Kent Towne Market. Crews arrived to find the store staff working to evacuate the store. FD personnel entered the store and conducted air monitoring as well as an overall investigation of the building. Crews on the roof located a malfunctioning HVAC unit. The unit was secured and the store re-opened.