CFM measures how much air your HVAC system moves per minute, like its breathing rate. The rule of thumb is 400 CFM per ton of cooling, but too little causes poor heat removal and humidity problems, while too much creates noise and drafts. Use manufacturer specs and static pressure tests, not guesses.
Hey, are you new to the trades? Here's something you may not know about CFM. CFM means cubic feet per minute. It is the volume of air a system moves every minute. Think of it as the system's breathing rate. Equipment is selected to move a target amount of air. A common cooling rule of thumb is around 400 CFM per ton, but the actual target can change with the equipment, Climate, and design. Why does it matter? Too little CFM means less heat and moisture come back across the coil, rooms may be uncomfortable, humidity can stay high, and the coil or heat exchanger can be stressed. Too much CFM can create noisy registers, drafts, and reduced efficiency. CFM is a spec, not a guess. A technician should use the manufacturer's data Blower settings, static pressure, and proper measurements to evaluate airflow, not just listen to the blower or count registers. She is checking whether the whole system is moving the air it was designed to move. Airflow affects everything the system does. Now that you know, you can help someone else know.
