La Cornue hood CFM terms are the words you meet on a hood spec sheet: CFM (how much air the blower moves each minute), baffle filter (the metal filter that traps grease), duct (the pipe that carries air outside), damper (the flap on the outside cap), make-up air (fresh air let in to replace what the hood removes), and recirculating (a setup that filters air and returns it to the room). Our Château hood pages list a four-speed blower of about 600 CFM through a 6-inch round duct, with three 20-watt halogen lights. This glossary explains each term in plain English so a spec sheet or a technician’s note makes sense.
What does CFM mean on a La Cornue hood?
CFM stands for cubic feet per minute, the volume of air a blower can move. Our Château Hood 120 page lists a four-speed blower of about 600 CFM with a 6-inch round duct. A bigger CFM number means more capacity, but it is not the whole story. Our venting guide explains that every elbow and every foot of duct reduces effective airflow, so the CFM on the label is a ceiling, not a guarantee. For any other hood, use the figure on its own spec sheet.
What is a baffle filter?
A baffle filter is a set of overlapping metal channels. Air is forced to change direction sharply as it passes through, and grease, being heavier, cannot make the turn and collects on the metal instead of entering the duct. Our hood explainer notes that these filters are reusable, and our baffle filter cleaning guide shows how to care for them. Clogged filters are the top cause of weak suction, so they are the first thing to look at when a hood seems to have lost its pull.
What are the duct, the damper and the cap?
The duct is the pipe between the hood and the outdoors. Our Château pages list a 6-inch duct, and the venting guide recommends smooth, rigid metal rather than flexible foil, in the shortest, straightest run you can manage. At the outside end is a cap with a backdraft damper, a flap that opens when the blower runs and closes when it stops, so outdoor air does not blow back in. A damper stuck partly closed chokes the airflow, as our weak suction guide explains.
What are make-up air and recirculating?
A hood that exhausts a lot of air from a tight home creates a slight vacuum. Make-up air is a deliberate supply of outside air to replace what leaves, so doors do not slam, and fuel-burning appliances are not backdrafted. Local codes may require it above a certain CFM, and our pages say to confirm the requirement with your installer. The threshold is set by code, so we do not give a number. Make-up air systems involve ducts, and sometimes dampers and controls, so they are a professional installation item.
A recirculating, or ductless, hood filters the air and returns it to the kitchen instead of sending it outdoors. Our sizing guide says a La Cornue hood performs best ducted to the outside, because heat, steam and grease actually leave, and that recirculating setups cannot match a ducted run for a high-BTU range. If your layout forces difficult routing, the guide’s advice is to prioritize the shortest, straightest path over raw blower CFM.
What are the canopy, the chimney, the speeds and the lights?
The canopy is the part over the range that captures the rising plume. The chimney is the vertical cover that hides the duct between the canopy and the ceiling or wall. The shapes differ by hood: the CornuFé styles are named Marquee, Loge, Cascade and Euclid, and Château hoods are identified by width. Our hood names glossary explains those names. The name is a design choice and does not change performance for a given size. Whether a chimney is adjustable on your hood, and how far, is in your installation sheet.
A four-speed control gives you low settings for a gentle simmer and high settings for searing or frying. Matching the speed to the cooking is quieter and extends filter life. The three 20-watt halogen lights are replaceable, and our halogen replacement guide covers the safe way to do it. Anything involving the blower motor, the switch or wiring belongs to a technician.
How do these terms fit together on a real hood?
Think of the hood as a chain. The canopy captures the plume. The baffle filters take out grease. The blower, rated in CFM, pulls the air through. The duct carries it outdoors, and the damper keeps outdoor air from blowing back. Make-up air replaces what left. If any link is weak, the whole system disappoints: a strong blower behind a clogged filter or a long, twisty duct underperforms, and a clean duct cannot fix a hood that is too narrow for the range. That is why our sizing and venting guides treat width, CFM and duct as one design. As a rule, the hood should be at least as wide as the range.
A hood that hums but barely moves air usually points to filters, duct or damper before the blower. A hood that smells of old grease needs its baffle filters cleaned. A hood that rattles at some speeds may have a loose filter or panel. A hood that blows back cold air when it is off has a damper that is not closing. Each of those uses a word from the glossary above, so you can describe it clearly when you call. For a blower that will not start, see the blower won’t start guide; motor and wiring work belongs to a technician.
