Patent attributes
Embodiments of the invention provide a system capable of reducing negative pressure. The system includes a make-up air system that can be configured and arranged to be installed within a structure, such as a building. The system can also include a pressure switch that is configured and arranged to sense a pressure within an exhaust duct coupled to an exhaust device. The pressure switch can also be configured to communicate an activation signal and a deactivation signal to the make-up air system. In some embodiments, communication of the activation and deactivation signals can be at least partially dependent on the pressure within the exhaust duct. Moreover, the pressure switch can be configured and arranged to be retroactively coupled to at least one of the exhaust duct and the exhaust device.