Answer:
A fan/blower should be used
Step-by-step explanation:
In a building the air pressure could be positive or negative and each if these depends on the air tightness of the building and could also be caused sometimes by wind and other factors.
When there is positive pressure, we have it that the pressure in the building is more than the outside pressure. Positive pressure also helps with an improvement in the quality of air in a building since it would take out smokes and other particulates.
Therefore to maintain positive pressure a fan or blower should be used.