Which method involves using a blower to remove hazardous atmosphere from a confined space?

The method that involves using a blower to remove hazardous atmosphere from a confined space is known as exhaust ventilation. This technique focuses on actively moving air out of a confined area to eliminate harmful contaminants or gases, thus improving the atmosphere within that space. By creating a negative pressure environment, exhaust ventilation helps to draw out the hazardous air, allowing for safer conditions for workers entering or working in the confined space.

Other methods might involve changing or moving air within the space but do so in different ways. Air exchange typically refers to replacing stale or contaminated air with fresh air, which does not emphasize removal as a primary action. Pressure relief deals with equalizing pressure to prevent potential hazards associated with pressure build-up but doesn't specifically focus on removing hazardous atmospheres. Mechanical ventilation generally describes the use of fans or blowers to circulate air within a space, but it does not necessarily specify the removal of hazardous atmospheres, as it may also just involve mixing air without actively extracting contaminants. Thus, exhaust ventilation is the most precise method for the purpose stated in the question.