Can exhaust fan be used as fresh air fan?

Yes, an exhaust fan can be used as a fresh air fan. However, it is important to note that the fan must be designed for both exhaust and fresh air applications. If the fan is not designed for both, it may not be able to provide the necessary air flow and pressure to properly ventilate the space. Additionally, the fan must be installed correctly to ensure that it is drawing in fresh air from outside and not recirculating air from within the space.