Why Kitchen Ventilation Matters

Cooking produces smoke, grease, and moisture that can linger in the air, leading to odors, poor indoor air quality, and even potential health concerns. A good vent hood:

• Removes airborne grease and smoke

• Reduces moisture buildup (which can lead to mold)

• Keeps kitchen air fresh

• Prevents excess heat from accumulating

However, a powerful range hood doesn’t just remove cooking fumes—it also affects the overall airflow of your home, which brings us to the HVAC connection.

The HVAC and Range Hood Balancing Act

Your home’s HVAC system is designed to maintain a balanced airflow. When a range hood operates, it pulls air from the kitchen and sends it outside. If too much air is removed without a way to replace it, your home can develop negative air pressure, which causes:

✅ Strain on the HVAC system
✅ Difficulty heating or cooling rooms
✅ Backdrafts from fireplaces or gas appliances
✅ Doors that are harder to open due to pressure imbalance

The solution? Choosing the right vent hood size and ensuring proper makeup air flow.

How to Choose the Right Range Hood

1. Determining the Right CFM (Cubic Feet per Minute)

CFM measures how much air a range hood can remove per minute. A common mistake is assuming that bigger is always better. Here’s how to calculate the correct CFM:

• Electric Stove: 100 CFM per linear foot of cooktop

• Gas Stove: Multiply the total BTUs of all burners by 100, then divide by 10

Example: A gas stove with four burners totaling 50,000 BTUs would require:
(50,000 ÷ 100) = 500 CFM

If you cook frequently or love high-heat cooking (like wok stir-frying), consider increasing the CFM by 20-30%.

2. Choosing the Right Hood Size

Your vent hood should be:

• At least as wide as your cooktop (standard recommendation)

• Ideally 3 inches wider on each side for better capture

Example: If you have a 30-inch stove, a 36-inch hood provides the best coverage.

3. Ducted vs. Ductless Ventilation

• Ducted Hoods: Vent air outside, providing better performance but requiring proper duct installation.

• Ductless Hoods: Use filters to recirculate air; best for apartments or homes without ductwork.

For better HVAC balance, ducted hoods are preferred as they fully remove pollutants rather than just filtering them.

4. Makeup Air: Replacing What’s Lost

To prevent negative air pressure, many building codes require makeup air systems for hoods over 400 CFM. A makeup air system introduces fresh air to balance what the hood removes.

Signs You Might Need Makeup Air:
✅ Your home feels drafty when the hood is on
✅ Your HVAC struggles to maintain temperature
✅ You notice smoke being pulled back into the house from fireplaces

If your range hood is 400 CFM or below, your home’s natural airflow may be enough. For anything above that, consult an HVAC professional about installing a makeup air unit.

Installation Tips for Better HVAC Performance

✅ Shorter duct runs = better efficiency (longer ducts reduce airflow)
✅ Use smooth metal ducting (flexible ducting creates resistance)
✅ Vent outside, not into attics or crawl spaces (prevents moisture buildup)
✅ Install a backdraft damper to stop unwanted air from entering

The Perfect Balance

Sarah eventually called an HVAC expert who installed a makeup air system for her 600 CFM hood. Almost immediately, she noticed a difference—no more stuffy air, and her heating and cooling worked as expected.

Choosing the right vent hood isn’t just about looks—it’s about keeping your kitchen air clean without disrupting your home’s HVAC balance. By considering CFM, sizing, and proper ventilation, you can cook comfortably while keeping your home’s airflow in perfect harmony.

FAQs

1. Do I really need a range hood if I have an open-concept kitchen?
Yes! Open kitchens still accumulate grease and odors, which can spread more easily without proper ventilation.

2. What happens if my hood is too powerful?
An overpowered hood can cause negative air pressure, affecting HVAC efficiency and even pulling carbon monoxide from gas appliances.

3. Can I install a range hood myself?
If it’s under 400 CFM, possibly. For anything higher, or if ductwork is required, it’s best to hire a professional.

4. How often should I clean my range hood filters?
For ductless hoods, clean filters monthly. For ducted hoods, wash grease traps every 2-3 months.

5. Is a quiet vent hood possible?
Yes! Look for hoods with multiple fan speeds and sones ratings of 4 or lower for quieter operation.