Why Kitchen Ventilation Matters

Cooking releases a cocktail of heat, moisture, grease, and odors into the air. Without proper ventilation, all of that lingers—making your kitchen (and your whole home) less comfortable and potentially unhealthy. Here’s what a good vent hood does:

• Removes smoke and airborne particles.

• Keeps humidity and heat levels down.

• Prevents grease buildup on walls and cabinets.

• Improves indoor air quality and comfort.

But a vent hood doesn’t operate in a vacuum—it pulls air out, and that air has to be replaced from somewhere. That’s where HVAC systems come into play.

The Vent Hood and HVAC Tug of War

Imagine your home as a carefully balanced ecosystem. Your HVAC system heats, cools, and circulates air in a closed loop. When you introduce a powerful vent hood into the mix, it begins extracting air—sometimes up to 1,200 cubic feet per minute (CFM).

Here’s the catch:

If the vent hood pulls out more air than your home can naturally replace, it creates negative pressure. This can lead to:

• Drafts from windows or doors.

• Backdrafting from fireplaces or gas water heaters (dangerous!).

• Decreased HVAC efficiency.

• Increased energy costs.

Especially in tightly sealed, energy-efficient homes, this pressure imbalance can disrupt the comfort and safety of your space.

Sizing Guidelines: Getting the CFM Just Right

One of the most common mistakes homeowners make is oversizing their range hood. Bigger isn’t always better—it’s about balance.

General Sizing Rules:

1. For Electric Cooktops:

• Minimum 100 CFM per linear foot of cooktop.

• A 30″ cooktop → 250–300 CFM vent hood.

2. For Gas Cooktops:

• 100–150 CFM per 10,000 BTUs.

• A 60,000 BTU cooktop → 600–900 CFM vent hood.

3. Island Hoods:

• Require more power (about 100 CFM more) due to open-air design.

4. Wall-Mount or Under-Cabinet Hoods:

• Better containment = lower CFM required compared to island hoods.

Balancing Airflow with Makeup Air Systems

Once your vent hood goes above 400 CFM, most building codes (like the International Residential Code) require a makeup air system. This system brings in fresh, tempered air from outside to replace the air being exhausted.

Key Benefits of Makeup Air:

• Prevents pressure imbalances.

• Keeps HVAC performance stable.

• Enhances indoor air quality.

If Sarah and Tom had installed a makeup air damper, they might have avoided those persistent drafts and hot/cold spots.

Ductwork: The Hidden Hero

Even the best vent hood will fail if it’s paired with poor ductwork.

Ducting Tips:

• Use rigid metal ducting (smooth interior = better airflow).

• Keep duct runs as short and straight as possible.

• Use gradual turns (not sharp bends) to maintain efficiency.

• Increase duct size for higher CFM (minimum 6” diameter for 300–400 CFM).

And don’t forget to vent outdoors—not into the attic or crawl space. Recirculating hoods with filters help, but they can’t fully replace outdoor venting.

Smart Design Considerations

When choosing a vent hood with HVAC in mind, don’t just focus on function—think about how it fits into your home’s airflow plan.

Ask yourself:

• Is my kitchen part of an open floor plan?

• How airtight is my home?

• Will I need a makeup air system?

• Is my HVAC system equipped to handle these changes?

Consulting with both an HVAC technician and kitchen designer can save you a ton of headaches later.

Wrapping It All Up

Choosing a vent hood isn’t just about how it looks above your stove—it’s about how it breathes with the rest of your house. From airflow to pressure balance, every detail matters when it comes to vent hood HVAC kitchens.

So whether you’re remodeling like Sarah and Tom or building from scratch, take the time to size your hood right, plan your ductwork, and consider your HVAC system’s role. Your future self (and your nose) will thank you.

FAQs

1. What does CFM mean for vent hoods?

CFM stands for “cubic feet per minute”—it measures how much air your vent hood can remove per minute.

2. Do I need a makeup air system for my vent hood?

If your vent hood is rated over 400 CFM, most building codes require one to maintain safe indoor air pressure.

3. Can a powerful range hood affect my heating or cooling?

Yes. A high-powered hood can disrupt HVAC airflow, causing drafts and higher energy bills if not properly balanced.

4. Are ductless range hoods effective?

They’re better than nothing but less effective than venting outdoors. Ductless models rely on filters to trap particles and odors.

5. How do I choose the right size vent hood?

Base it on your cooktop size and fuel type. Use CFM guidelines (100 CFM/ft for electric, or 100–150 per 10,000 BTUs for gas).

6. What happens if I don’t vent my hood outdoors?

Humidity, grease, and odors can linger, reducing air quality and possibly damaging your home over time.

7. Does vent hood height matter?

Yes. Typically, vent hoods should be installed 24–30 inches above an electric cooktop and 27–36 inches above gas.

8. Can I connect my vent hood to my HVAC ducts?

No. Vent hoods need dedicated ductwork. Sharing ducts can be unsafe and violates most building codes.