How many air changes per hour do laminar/mass air displacement systems typically achieve?

Laminar/mass air displacement systems are designed to provide a high level of air cleanliness and control in laboratory environments. Achieving 200 or more air changes per hour is characteristic of these systems, as they need to effectively remove contaminants and provide a sterile or clean environment, particularly in facilities handling sensitive biological materials.

The high air change rate helps to ensure that particulate matter, microorganisms, and other potential pollutants are quickly removed from the space. This is crucial in laboratory settings where air quality can significantly affect experimental results and the well-being of animal subjects.

While options such as 100, 150, and 250 air changes are also relevant in different contexts or types of ventilation systems, the correct answer of 200 or more reflects the standard practice in environments where strict air cleanliness protocols are enforced, especially in areas requiring laminar flow to protect both the subjects and the integrity of the experiments being conducted.