A range hood is rated on paper and judged at the stove. A fan can move a respectable volume of air on a spec sheet and still leave the cooking plume hanging in the kitchen if the hood is mounted too high, the duct is undersized, or the house cannot supply the air being pulled out. Before you buy a replacement filter or a new hood, run a capture test at the burner you use most.
ACHR News reports that HVAC contractors face rising material costs and federal funding uncertainty while SMACNA pushes for indoor air quality legislation, as described in its ACHR News policy story on the trade's regulatory outlook. Whatever happens in that debate, the cooking plume in your kitchen behaves the same way. The useful work is in the kitchen itself.
Run the Paper Test First
Turn the hood to its highest speed and hold a strip of tissue paper or a lit stick of incense at the front edge of the hood, about where the pan sits. Watch which way the smoke or paper moves. A well-captured plume leans toward the hood and gets pulled up into the intake. If the smoke rolls out past the front edge, toward your face, the hood is not catching what the burner throws up.
Repeat the test at the front burner, the rear burner, and the back of the cooktop if the hood is wide. Note each result. A hood that captures at the front but fails at the rear usually has a mounting height or width problem, not a fan problem.
Check the Electrical Side
Use your multimeter to confirm the voltage at the hood's connection is close to what the nameplate calls for. A fan running on a sagging supply will move less air than its rating and may run warm. If you have a clamp meter, clamp one conductor on the fan leads and compare the reading with the amp rating on the nameplate. A draw well above the rating points to a binding motor, a failing bearing, or a fan wheel fouled with grease.
Check the Air the House Can Give Back
A kitchen exhaust fan removes air, and the house has to replace it. In a tight house, the hood fights itself. Close the kitchen doors, run the hood on high, and listen for whistling at door gaps or a fan that seems to labor. A sealed house with no intentional makeup path can pull combustion gases the wrong way.
Check the gas water heater and furnace while the hood runs. Hold a tissue at the draft hood or the flue opening. If the tissue is pulled into the flue, or the burner flame leans toward the room, the appliance is backdrafting. Stop the test and call a qualified technician. Do not treat a hood upgrade as the fix for a backdrafting appliance.
Follow the Duct to Daylight
A ducted hood has to deliver its air outdoors, and the duct is part of the fan's load. Look for flex duct that sags into low spots where grease collects, crushed sections, and more elbows than the run needs. Each bend and each foot of length adds resistance, so a short, straight run of smooth metal beats a long, twisted one. Confirm the exterior termination has a backdraft damper that opens freely and is not blocked by a bird screen full of lint.
If the hood's rating assumes a short run and your run is long, the capture you measured at the stove is the number to trust, not the brochure's maximum speed.
Filters Come Last
A recirculating hood with a charcoal filter returns the air to the kitchen. It can reduce some odors and grease, but it does not remove carbon monoxide or nitrogen dioxide from a gas burner. If your concern is combustion gases, a recirculating hood will not answer it, and a new filter will not change that.
For a ducted hood, the grease filter is the first thing to clean. A clogged mesh cuts airflow before any other part fails. Clean it by the manufacturer's method and recheck the paper test before you decide the hood is undersized.
Write Down the Results
Keep a short log beside the hood: burner tested, paper result at high speed, measured voltage, amp draw against the nameplate, makeup air observations, and duct route. The log turns a vague complaint about smoke into a specific problem you can hand to a technician or fix yourself. Most kitchens that fail the capture test fail for one of these reasons, and the log will show which one.