Why Kitchen Ventilation Matters (Even in Winter)

Every time you cook—especially with gas—you release heat, moisture, smoke, and sometimes harmful particles like carbon monoxide or nitrogen dioxide into the air. That’s where vent hoods (aka range hoods) step in.

They capture:

• Heat and grease particles from cooking

• Moisture and steam, which can lead to mold

• Odors and potentially harmful gases

But here’s the kicker: if your vent hood is too powerful or poorly vented, it can suck conditioned air right out of your house—creating negative pressure and throwing off your entire HVAC system.

The Balancing Act: Vent Hoods & Your HVAC System

In many homes, the HVAC system and the kitchen vent hood are like two people on a seesaw. If one pulls too hard, the other gets out of balance.

Here’s how that plays out:

• High-powered vent hoods (common in gourmet kitchens) can pull up to 1200 CFM (cubic feet per minute) of air out of your home.

• Unless that air is replaced through make-up air systems, your furnace or air conditioner has to work overtime to compensate.

• This imbalance can lead to drafts, backdrafting from gas appliances, and higher energy use.

Real-World Example:

Imagine cooking a holiday meal while your 900 CFM vent hood roars above the stove. Meanwhile, cold air is seeping in through door gaps and vents to make up for the air being expelled—chilling your toes even while the kitchen’s warm.

Proper Ventilation for Cooking: Best Practices

1. Choose the Right Vent Hood for Your Kitchen

• Wall-mount and under-cabinet hoods: Great for standard stoves.

• Island hoods or downdraft systems: Best for open kitchens or island ranges.

• CFM Guidelines:

  • Electric cooktops: ~100 CFM per linear foot.

  • Gas ranges: 100–150 CFM per 10,000 BTUs.

  • Heavy-duty cooking (e.g., frying): Consider 600+ CFM.

2. Use Make-Up Air Systems

These are dedicated vents that bring in outside air to replace what your hood removes. In many areas, local codes require them if your hood exceeds 400 CFM.

3. Ducting Matters

• Use rigid ducting (not flexible) for better airflow.

• Keep ducts as short and straight as possible.

• Always vent outside—never into an attic or crawlspace.

4. Keep It Clean

• Grease filters should be cleaned monthly.

• Metal mesh or baffle filters are dishwasher-safe.

• Clogged filters reduce performance and increase fire risk.

Sizing Your Vent Hood: A Quick Guide

Rule of Thumb:

• For gas: Add up the BTUs and divide by 100.

• For electric: Match 100 CFM per linear foot of stove.

If you regularly cook with strong odors (like curries or fish), lean toward the higher end.

How It Ties Back to Winter Comfort

So, what does all this mean when you’re trying to winterize your home?

• Leaky or unbalanced kitchen ventilation can let cold drafts in or interfere with your furnace’s ability to keep the house warm.

• Ensuring your vent hood is properly sized, well-maintained, and balanced with a make-up air system helps your HVAC work smarter, not harder.

• It also improves indoor air quality, which is extra important in winter when windows are usually closed tight.

Conclusion: Keep the Air Flowing Right

Your kitchen isn’t just where meals are made—it’s a powerful player in your home’s energy ecosystem. Paying attention to how your vent hood and HVAC system interact can make a big difference in comfort, air quality, and efficiency, especially in the winter months.

Next time you fire up the stove, you’ll know your ventilation is working with—not against—your HVAC. And that’s one more win for cozy, healthy living.

FAQs

1. What is a make-up air system, and do I really need one?

Yes, if your vent hood is over 400 CFM, building codes often require a make-up air system to replace the air being exhausted—especially in tight, energy-efficient homes.

2. Can a vent hood make my house colder in the winter?

Absolutely. Without proper make-up air, vent hoods can cause cold outside air to sneak in through cracks and vents, disrupting your HVAC system.

3. What size vent hood do I need for a 36″ gas range?

For a 36” gas range with 60,000–90,000 BTUs, aim for a 900–1200 CFM hood. Don’t forget to factor in make-up air.

4. Do I need to run the vent hood on low, medium, or high?

Use the lowest effective setting while cooking. High is best for searing or heavy smoke; medium for daily use; low during simmering or warming.

5. Can I vent my hood into the attic or crawlspace?

No. Always vent to the outdoors to avoid mold, moisture damage, and poor air quality.

6. Is it OK to use a recirculating hood?

They’re fine for apartments or where outdoor venting isn’t an option, but they don’t remove moisture—just filter grease and odors.