UNDERSTANDING THE VENTILATION POWER REQUIRED (CFM)*
The measurement used for vent power is cubic feet per minute (CFM). This measures the velocity at which air flows into or out of the space. Some manufacturers include the certified ratings to HVI 916* Airflow Test Procedure or AHAM HRH-2-2019** Standards as part of their CFM rating.
*Home Ventilation Institute (HVI)
**Association of Home Appliance Manufacturers
Home Ventilation Institute (HVI)
When a ventilation product is HVI certified, it means that the air flow (CFM rate) and noise level (sones) have undergone testing to determine if it will perform as stated under the rated conditions. Visit the HVI website (www.hvi.org) to see if your ventilation product has been HVI certified and how it will perform based on your desired type of installation (duct configuration and some speed settings).
Association of Home Appliance Manufacturers (AHAM) Verification
If a ventilation product has been AHAM Verified then an impartial verification of the manufacturer’s air flow (CFM) and noise level (sones) under a variety installation options has been performed. To know if your vent has been AHAM Verified or not, visit www.aham.org. If it has, you should be able to view the results*.
Choosing the Right CFM
It's important to choose an appropriately sized ventilation unit with the right CFM level. The downside of buying a product with a too-low CFM rating, is that it may be unable to successfully ventilate the air in your kitchen. The downside of buying a ventilation system with too high of a CFM level, is that it can create negative pressure, which will result in having to find another method to replenish the air. Furthermore, if the CFM level is too high, air can be removed from places where you may not want it to be removed from.
With respect to figuring out the minimum CFM requirements, think about the cooking techniques you use most often.If you like to sear, blacken and fry or generally use 4 or more burners you may require a higher CFM rating to refresh the air. However higher the CFM the louder the hood will sound. If simmering and sautéing are your favourite techniques, or you normally use only 2 burners, a lower CFM rating could work.