Why Ventilation Matters in Canadian Kitchens

Canada’s weather doesn’t leave much room for error—especially in winter. Kitchens are hotspots for heat, moisture, and indoor pollutants. Boiling pasta, frying bacon, or running the dishwasher all generate steam, grease particles, and sometimes even carbon monoxide (if using gas stoves).

Without proper ventilation, you risk:

• Lingering odors and grease buildup

• Mold from excess moisture

• Imbalanced indoor air pressure

• Poor indoor air quality, especially in airtight homes

A vent hood, when properly designed and installed, whisks away contaminants and helps your HVAC system maintain healthy air quality without working overtime.

The Role of Vent Hoods in HVAC Balance

Vent hoods might seem simple—they suck air up and out. But this air has to come from somewhere. If a powerful range hood pulls air out without enough incoming air (known as makeup air), it creates negative pressure inside your home.

What Happens When There’s Negative Pressure?

• It pulls in unconditioned outdoor air through gaps in windows or doors.

• It backdrafts combustion appliances like water heaters or fireplaces.

• Your HVAC system struggles to maintain consistent indoor temperatures.

This is especially tricky in ductless homes using mini-split systems, which are more sensitive to pressure and air movement changes due to their zoned nature.

Sizing Guidelines for Vent Hoods (and What It Means for HVAC)

The size and power of your vent hood should match your cooking habits and your HVAC system’s capacity.

General Sizing Rules:

• Electric cooktops: 100 CFM (cubic feet per minute) per linear foot of cooktop.

• Gas ranges: 150 CFM per linear foot due to higher heat and combustion byproducts.

• High-output cooking (wok cooking, indoor grilling): Go higher—up to 600–1200 CFM.

But Here’s the Catch:

• Overpowered hoods without makeup air = HVAC chaos.

• In most parts of Canada, local building codes require makeup air for hoods over 300 CFM.

• Makeup air can be introduced via a mechanical system that brings in outdoor air and tempers it before releasing it into the home—something ductless systems aren’t always designed to handle.

Mini-Splits + Kitchens: What You Need to Know

Mini-split systems offer great flexibility and energy efficiency, especially in retrofits or additions where ductwork isn’t feasible. But they need special consideration when installed near kitchens.

Key Considerations:

• Avoid placing heads near the stove or hood to prevent grease buildup and short cycling.

• Ensure airflow isn’t disrupted by the vent hood’s draw.

• Coordinate with your HVAC pro to manage makeup air effectively—some mini-split systems can integrate with energy recovery ventilators (ERVs) or heat recovery ventilators (HRVs) to help balance air pressure and improve indoor air quality.

Real-World Scenario: Balancing Ventilation in a Canadian Home

Let’s revisit Sarah and Mark. Their new 600 CFM range hood was perfect for their gourmet kitchen—but it overwhelmed their ductless mini-split system, especially in winter. Cold air seeped in through cracks, and their heat pump couldn’t keep up.

With the help of an HVAC contractor, they installed a makeup air unit with a temperature sensor, ensuring incoming air was pre-warmed before entering. They also added a low-profile ERV in the laundry room to improve air exchange without needing full ductwork.

Now, their mini-split works efficiently, and their home stays warm—even when they’re cooking up a storm.

Conclusion

Proper ventilation isn’t just about keeping your kitchen air fresh—it’s about preserving the health of your home and HVAC system. Especially in Canadian climates, vent hoods and HVAC systems must be designed to work together, not against each other.

If you’re considering a ductless mini-split, make sure your ventilation plan supports it. Get your vent hood properly sized, understand your makeup air needs, and coordinate the system so your kitchen stays cozy and functional—year-round.

FAQ: Vent Hood HVAC Kitchens

1. Why does my house get cold when I use the range hood?

High-powered range hoods remove warm air without replacing it. Without makeup air, the house pulls in cold outdoor air to compensate, creating drafts and HVAC strain.

2. What is makeup air and do I need it?

Makeup air replaces the air vented out by your hood. In Canada, codes typically require it for hoods over 300 CFM. It keeps air pressure balanced and prevents cold drafts or appliance backdrafts.

3. Can a ductless mini-split handle kitchen ventilation needs?

Mini-splits don’t handle kitchen ventilation directly. They need to be paired with a proper ventilation strategy, including vent hoods and possibly ERVs or HRVs.

4. Is a ducted or ductless range hood better for my HVAC?

Ducted hoods vent outside, which is best for air quality but affects indoor pressure. Ductless (recirculating) hoods filter and recirculate air, reducing pressure impact but less effective overall.

5. Where should I install my mini-split in relation to the kitchen?

Avoid placing the indoor unit directly near the stove or hood to prevent grease contamination. Aim for adjacent walls or open areas for better airflow distribution.

6. Does installing a vent hood increase energy bills?

Potentially yes—especially without makeup air. The system might have to work harder to maintain comfort. But when balanced properly, it actually improves efficiency by maintaining indoor air quality.