Venting Your Range Hood Through the Wall: The Complete Walkthrough

Hey there! If you‘re reading this, you‘re probably looking to vent your range hood outside through the wall. This is a smart move – properly venting your range is crucial for trapping cooking fumes, grease, and moisture and sending them outside instead of spreading them around your home.

I‘ve installed range hoods in tons of homes over my career, so I wanted to share my complete expertise to help you do this project right. In this guide, we‘ll cover everything you need to know to plan and install a range hood vent like a pro.

Why Proper Ventilation Matters

Before we dig in, let me quickly explain why proper ventilation really matters for your range hood:

• Removes grease: Stop grease buildup in your kitchen. Your hood traps all that cooking grease and oils, keeping it from spreading and sticking to your walls and cabinets.

• Eliminates odors: No more smelling last night‘s fish dinner while you eat breakfast. Vented range hoods remove food odors rather than spreading them around the house.

• Improves air quality: Cooking releases moisture, smoke, VOCs, and other pollutants into the air. Venting these outside keeps your indoor air fresh and breathable.

• Prevents mold: All that cooking humidity gets exhausted outside before it can condense on your walls and breed mold, mildew and bacteria.

• Increases home value: Upgrading to an effective vented range hood adds value when you go to sell your home later on.

See why it‘s worth doing this project right? Now let‘s get into the details so you can vent your range like a pro.

Choosing the Right Ductwork

The type of ductwork you select will have a big impact on your system‘s airflow and efficiency. Here are your main options:

Galvanized Steel

• Pros: Very rigid and durable. Long lifetime expectancy of 30+ years. Stands up to heat and grease well.

• Cons: Harder to install around corners. Needs all seams sealed thoroughly with silicone.

Aluminum

• Pros: Lightweight and easy to install. Low cost. Snaps together quickly.

• Cons: Prone to dents and damage. Seams can separate over time. Lifetime only around 15-20 years.

Stainless Steel

• Pros: Strongest and most durable option. Easy to clean grease buildup. Withstands heat and moisture.

• Cons: Installation takes more time. Requires screws/rivets to join sections. Most expensive option.

My recommendation would be stainless steel for its strength and longevity, assuming it fits in your budget. Galvanized steel is a good alternate option.

The duct size must match the outlet on your range hood – usually between 3-1/4” to 10”. Never reduce duct size as this restricts airflow.

Calculating Optimal Duct Length

When planning your duct run, shorter is better for maximum airflow:

• Under 15 feet is ideal
• Up to 25 feet is good
• Keep it under 50 feet maximum

Each elbow and bend adds airflow resistance too. Here are the deductions I recommend:

• Smooth 45° elbow: 2 feet
• 90° elbow: 5 feet
• Flexible 45° elbow: 4 feet
• Flexible 90° elbow: 10 feet
• 1 foot of flexible duct: 1 foot

So if your duct run has two 90° elbows and 5 feet of flexible duct, deduct around 20 feet from your total length allowed.

Picking the Best Hood Location

Mounting the hood in the optimal spot will make your installation and venting much simpler. Here are a few pointers:

• Install it centrally over your cooktop or range – this captures more smoke and grease.

• Hoods should be mounted 18-30 inches above the cooking surface for maximum effectiveness.

• Minimize duct length and elbows by choosing a hood location with the shortest route outdoors.

• Confirm the attic or roof has no blocking issues where you‘ll vent the ductwork outside.

Selecting the Best Wall for Venting

Venting through an exterior wall is ideal. This allows the shortest, simplest duct run. Some things to consider when picking your vent wall:

• Avoid kitchen walls with plumbing pipes or electrical wiring inside. Opening one up makes your project way harder!

• The vent hood should align closely with the center of your range hood – this looks best and maximizes capture efficiency.

• North-facing walls are best to avoid excessive heat/cold from direct sun exposure.

• Make sure the wall material (stucco, wood siding, etc) is suitable for cutting a vent hole.

If an exterior wall isn‘t feasible, you can also vent through the roof. This requires more complex ducting like a gooseneck to go vertical.

Preparing the Vent Hood

Once you‘ve mapped out the plan, it‘s time to get the vent hood itself ready. You‘ll need to:

• Assemble the range hood chassis according to the manufacturer‘s instructions

• Attach the duct collar or transition piece to the hood outlet

• Securely mount the range hood to the wall following the installation guide. It must be sturdy with no movement or vibration.

• Install a backdraft damper over the transition piece outlet. This allows air to flow out but not back in.

Installing the Wall Vent

The next key step is installing the actual vent that will connect to the outside. Here‘s how:

• Choose an exterior wall vent hood that matches your duct size and has a built-in damper. Low profile and mushroom caps work well.

• Trace the outlet onto the wall where you want to install it. Cut a hole about 1/4” larger all the way around so the vent fits easily. I recommend using a reciprocating saw for clean cuts.

• Insert the vent hood into the hole and fasten through the backplane securely into the wall framing with 3-4 screws.

• Seal all around the exterior edge with silicone caulk. This prevents air and moisture from leaking through. I also recommend wrapping exposed duct edges with aluminum tape for maximum weatherproofing.

• Make sure the hinged flap on the vent hood opens freely outward. This allows air to exit while blocking backdrafts.

Connecting it All with Ductwork

Here comes the fun part – running the ductwork that connects your range hood to the outside vent. Follow these best practices:

• Attach duct by holding it up to the damper outlet on the hood and the wall vent outlet. Adjust to minimize bends.

• Secure every joint completely with foil duct tape to prevent leaks. Leaks let grease and moisture escape into your walls.

• Slope ducts slightly downward from hood to vent at 1/4” drop per foot. This allows grease to run out instead of pooling in the ducts.

• Try to use straight rigid duct sections connected by adjustable elbows whenever possible. This is smoother than turning a flexible duct.

• Only use flexible duct to bridge small gaps. Keep flexible portions as short as possible to prevent sagging.

• Support flexible duct with metal straps if needed to prevent sagging. Drooping sections create grease traps.

• For efficient airflow, avoid sharp 90° turns – use two 45° elbows instead or long radius curves.

Once all the connections are air-tight, you‘re almost done!

Finishing Touches

You‘ve done the heavy lifting – now just a few finishing steps to complete your venting system:

• Insulate around the exterior vent hood by back-filling with Roxul insulation. This prevents outdoor air from leaking indoors.

• For cold climates, install a layer of rigid foam insulation over the vent to minimize frost buildup.

• Caulk any gaps or seams around the vent hood with exterior silicone sealant. This stops air leaks and water intrusion.

• Make sure the outdoor vent hood is installed above the maximum expected snow line. You don‘t want it getting buried!

• Remove any dust or debris from the fan blades and interior ducts so they are clean before using the hood.

• Turn the fan on and check for leaks! Seal any leaky connections with additional tape.

That‘s it – you now have a fully functional range hood venting system that will serve you well for years to come. And you did it all yourself like a pro!

FAQs

Here are answers to some common questions on range hood venting:

What if I don‘t have an exterior wall near my range?

You can duct horizontally to a side wall by adding a 45° elbow off the back of the hood. This allows the air to make the turn while minimizing restriction.

Can I vent into the attic instead of outside?

No! Venting moisture and grease into your attic can cause major issues like mold growth and even fire hazards. Always vent range hoods fully outside.

Do I need to install makeup air?

In tighter modern homes, venting large amounts of air can create backdrafting issues. Consulting an HVAC pro about installing makeup air helps equalize indoor pressure.

How often should I clean the ducts?

I recommend inspecting and cleaning the range hood ducts every 2-3 years. This prevents dangerous grease buildup that can fuel fires.

Should I use all flexible ductwork?

No, flexible duct is prone to sagging over time which can create grease traps. Use solid metal for the majority of the run and just use short flexible portions as needed.

I hope this guide gives you everything you need to install your range hood venting like a professional! Let me know if you have any other questions as you go through your project. Happy venting!