You’ve probably spent a good amount of time picking out the perfect range hood for your kitchen. Maybe you went with a sleek stainless model, or a stylish chimney style that matches your cabinets. But here’s something many homeowners overlook: the ductwork that connects your range hood to the outside world. Without proper ducting, even the most expensive range hood is about as useful as a paper fan. Let’s talk about why ducting matters, what your options are, and how to avoid the most common mistakes that can turn your kitchen into a smoky, greasy mess.

First, let’s get one thing straight: a range hood’s main job is to suck up cooking fumes, smoke, grease, and moisture from your stovetop and send them outside. That’s called “ducted” or “vented” operation. There’s also a “recirculating” option, where the hood filters the air and blows it back into the kitchen. If you can possibly run ductwork to the outside, do it. Recirculating hoods are less effective at removing heat and humidity, and they require regular filter changes to keep from just blowing greasy air around your home. So for serious cooks, a properly ducted range hood is the way to go.

Now, the ductwork itself is usually made of rigid metal—either galvanized steel or aluminum. And here’s a big tip: avoid flexible plastic or foil ducts. They’re tempting because they’re easy to snake around obstacles, but they create turbulence and collect grease buildup, which is a fire hazard. Rigid metal ducts are smoother, so air flows freely, and they’re much easier to clean. If you must use flexible metal duct for a short section, keep it as straight and short as possible.

The diameter of the duct matters too. Most range hoods come with a 6‑inch or 7‑inch round outlet. You want to match that size throughout the run. Going smaller than the hood’s outlet forces the fan to work harder and makes a lot of noise. Going larger can actually reduce airflow because the fan isn’t designed to push air into a bigger pipe. Stick with the manufacturer’s recommendation—usually 6 inches for standard residential hoods, or 7 or 8 inches for higher‑performance models.

Another key point: keep the duct run as short and straight as you can. Every turn and every foot of length reduces the hood’s efficiency. Each 90‑degree elbow is like adding several feet of straight duct. So if your kitchen layout forces you to make a turn, use two 45‑degree elbows instead of one sharp 90—that’s much gentler on airflow. Also, try to keep the total length under about 25 to 30 feet, including the equivalent length of elbows. If you have to go longer, you may need a more powerful fan.

Where does the duct exit your house? Typically through a wall or the roof. If you go through the roof, you’ll need a roof cap that keeps rain and critters out. Through a wall, use a wall cap with a damper that opens when the fan is on and closes when it’s off. That damper is important—it stops cold drafts and pests from coming back in. Make sure the cap is installed with the louvers facing down to keep out weather.

One common DIY mistake is running the duct too close to the microwave or refrigerator. The heat from those appliances can damage the duct over time. Keep at least a few inches of clearance, especially near the top of the range hood where the duct connects. Also, never run the duct through an attic without insulating it. In cold climates, uninsulated duct will collect condensation, which leads to rust and mold. In hot climates, it can cause heat gain that makes your air conditioner work harder.

What about the electrical side? Your range hood needs its own dedicated circuit, or at least a circuit that isn’t shared with high‑draw appliances. Check the hood’s amperage rating and make sure the wiring and breaker are sized correctly. If you’re not comfortable working with electricity, call an electrician. But for the ductwork itself, many confident DIYers can handle the job with basic metal‑cutting tools, sheet metal screws, and aluminum tape (not duct tape—that stuff dries out and fails). Just remember to use metal screws, not drywall screws, and seal every joint with foil tape or mastic to prevent air leaks.

Finally, think about noise. A properly sized and installed duct system makes a huge difference in how loud your range hood sounds. If you’ve ever heard a hood that screams like a jet engine, chances are the ductwork is too small, too long, or full of sharp turns. Smooth, short, straight metal duct keeps airflow quiet. You can also add a sound‑dampening wrap around the exterior of the duct in the ceiling or attic to further reduce noise.

So before you cut that first hole in your wall or ceiling, take a minute to plan your duct route. Measure twice, buy rigid metal duct, avoid unnecessary bends, and cap it properly. Your range hood will thank you by working efficiently, staying quiet, and keeping your kitchen free of smoke and grease. And when you’re done, you can stand back and enjoy a home‑cooked meal without that annoying lingering smell.