ASHRAE 62.1 Standards And Air Systems Practice Test

The distinction being tested is how outdoor-air requirements are allocated. In space-by-space ventilation, the outdoor-air rate is specified for and applied to each individual space, so different rooms can have different rates based on their use and occupancy. In system-wide ventilation, a single central outdoor-air rate is established for the whole building and distributed through the system to all spaces. So the statement that space-by-space ventilation applies rates to individual spaces while system-wide uses a central rate accurately describes the difference. The other ideas don’t fit: system-wide is not inherently more or less efficient in all cases, and space-by-space ventilation does consider occupancy because those per-space rates often depend on how many people use the space. System-wide ventilation isn’t limited to local exhaust; it involves the central supply and distribution to the spaces, not just exhaust only.