What is the typical airflow exchange rate for a single-occupancy room?

• A. 1 to 2 exchanges per hour
• B. 6 to 12 exchanges per hour
• C. 3 to 5 exchanges per hour
• D. 15 to 20 exchanges per hour

Answer: (B)

Air changes per hour (ACH) tell us how often the room’s air is replaced in one hour. For a typical single-occupancy room, the ventilation is usually designed to provide about 6 to 12 ACH. That means the whole room air is refreshed roughly every 5 to 10 minutes, which helps dilute carbon dioxide, odors, and contaminants while keeping comfortable conditions.

Why this range fits well: it balances adequate air renewal with energy efficiency and comfort. If the rate were much lower, such as 1–2 ACH or 3–5 ACH, air quality would degrade as contaminants and CO2 accumulate. If it were much higher, like 15–20 ACH, the space could experience unnecessary drafts and energy use—appropriate for highly sensitive settings (such as operating rooms or certain isolation rooms), but not typical single-occupancy patient or office rooms.