Why Kitchen Ventilation Matters

Cooking produces a surprising amount of heat, moisture, and airborne particles. Grease, smoke, steam, and odors don’t just vanish—they linger, stain walls, and affect indoor air quality. That’s why good ventilation is key.

Benefits of Proper Kitchen Ventilation:

• Improved air quality: Reduces carbon monoxide and airborne pollutants.

• Moisture control: Prevents mold and mildew from excess steam.

• Odor removal: Keeps your home smelling fresh.

• Cleaner surfaces: Fewer grease particles mean less frequent deep cleaning.

But here’s the thing—when your vent hood starts pulling more air out of your home than your HVAC system can replace, problems arise.

How Range Hoods Impact HVAC Balance

Your HVAC system is designed to keep air pressure and temperature steady throughout your home. A powerful range hood—especially one over 600 CFM (cubic feet per minute)—can throw that balance off.

What Happens When Air Pressure Drops?

• Cold air gets pulled in through cracks and windows (known as backdrafting).

• Furnace efficiency drops.

• Indoor temperatures fluctuate, especially in open-concept homes.

• Carbon monoxide from gas appliances may be pulled back inside—a major safety risk.

This is especially important in Canadian climates, where winter drafts can significantly impact heating efficiency and comfort.

Sizing Guidelines for Range Hoods in Canadian Kitchens

Choosing the right size vent hood isn’t just about matching your stove—it’s about balancing airflow. Here’s how to do it:

1. Match Hood Power to Cooktop Type

• Electric cooktops: 100 CFM per 10 inches of cooktop width.

• Gas cooktops: 100 CFM per 1,000 BTUs of burner output.

• For example, a gas range with 40,000 BTUs total should have a hood rated at least 400 CFM.

2. Account for Duct Length and Turns

• Long or bendy ductwork reduces efficiency.

• Add 25 CFM for each 90° bend.

• Aim for a straight, short path outdoors with a dedicated exhaust.

3. Use a Makeup Air System for Hoods Over 400 CFM

• These systems bring in fresh outdoor air to “make up” for what’s being vented.

• Required by building codes in many Canadian provinces.

• Helps prevent HVAC imbalances, backdrafting, and cold spots.

Best Time of Year to Replace or Adjust Your HVAC System

So, when is the best time to replace or upgrade your HVAC—especially if you’re installing a new vent hood?

Spring and Fall: The Sweet Spots

• Mild weather: You won’t be reliant on heating or cooling during the transition.

• Off-peak season: HVAC contractors are more available, and prices may be lower.

• Prepares your home: Just in time for Canada’s harsh winters or humid summers.

If your kitchen upgrade includes a vent hood that impacts airflow, spring or fall gives you a buffer to install a new HVAC system—or adjust dampers and air returns—without interrupting comfort.

Conclusion: Don’t Let a Vent Hood Ruin Your Comfort

Lisa eventually had an HVAC technician assess her system. The verdict? Her 900 CFM range hood was pulling more air than her 15-year-old furnace could compensate for. By upgrading her HVAC and adding a makeup air system, her kitchen became a place of comfort once again—not a drafty vortex.

Whether you’re planning a kitchen reno or facing the end of your HVAC system’s life, remember this: vent hood HVAC kitchens need to work together—not against each other. A little planning, the right timing, and smart sizing can make all the difference.

FAQs About Kitchen Ventilation and HVAC

1. What is a makeup air system and do I need one?

If your range hood is over 400–600 CFM, it’s recommended (and often required by code) to install a makeup air system. It prevents negative pressure by supplying fresh air from outdoors.

2. Can I install a powerful vent hood in a condo or apartment?

You can—but you’ll need to ensure proper ducting and airflow management. In high-rises, recirculating hoods with filters are often used instead of exterior venting.

3. How do I know if my HVAC system is unbalanced?

Signs include drafty rooms, uneven temperatures, struggling HVAC performance, and increased energy bills after installing a high-powered range hood.

4. Is it safe to vent my kitchen into the attic?

No. Venting into an attic can cause moisture buildup, mold, and fire hazards. Always vent directly outside.

5. What’s the ideal duct size for a range hood?

Most standard hoods use 6″–8″ ducts. More powerful units may require 10″ or more. Undersized ducts cause noise, backpressure, and poor performance.

6. How often should I replace HVAC filters if I cook often?

If you cook daily, especially with gas or oil, replace or clean your filters every 1–2 months to keep air quality high.

7. Can a range hood work without an exterior vent?

Yes, through recirculating hoods with charcoal filters—but they’re less effective for serious cooking or gas stoves.