Why Cooking Ventilation Matters—Especially in Canada

In Canada, where homes are built tighter to conserve heat, cooking odors, moisture, and pollutants don’t just drift away. They linger.

The Problem:

• Frying, boiling, and roasting release moisture, grease particles, and combustion gases.

• Without a proper vent hood, this mix recirculates through your home.

• It forces your HVAC system to work harder, especially the furnace, which struggles to maintain comfortable temperatures and air quality.

In extreme cases, excess humidity can shorten the lifespan of your furnace—moisture causes rust, and dirty air filters clog up faster when airborne grease is involved.

How Range Hoods Impact HVAC Balance

Let’s go back to Martha’s house.

After installing a high-powered range hood rated at 900 CFM (cubic feet per minute), her foggy window problem vanished. But she encountered another issue: her furnace room began drawing cold air from under the front door. Why?

Her vent hood was too powerful for her home’s makeup air system.

Here’s What Happened:

• The vent hood was pulling out 900 CFM of warm, indoor air.

• Her house, being airtight, couldn’t draw enough air back in fast enough.

• This created negative air pressure, which disrupted her furnace’s combustion process and caused uncomfortable drafts.

This is a common problem in homes across Canada, particularly newer builds with better insulation. Your HVAC system and vent hood must work together, or they’ll throw your home’s air balance out of whack.

Sizing Guidelines: How Big Should Your Range Hood Be?

Choosing the right range hood isn’t about going big. It’s about going smart.

Here’s How to Size Your Vent Hood:

1. Match CFM to Your Cooktop

• Electric ranges: 100 CFM per linear foot of stove width.

• Gas ranges: 150 CFM per linear foot.

Example: A 30” gas range = 150 x 2.5 feet = 375 CFM

2. Consider Cooking Style

• If you do a lot of high-heat wok cooking or frying, go higher in CFM.

• Light cooking? You can scale back.

3. Match Hood Width to Stove Width

• Ideally, the hood should be as wide or slightly wider than your range.

• For island hoods, increase CFM by 100–200 because air has no surrounding walls to contain it.

4. Don’t Forget Makeup Air

• Any hood over 400 CFM requires a makeup air system by code in many Canadian provinces.

• These systems bring in outdoor air to replace what’s being vented—keeping air pressure balanced.

5. Duct Size & Length

• Undersized ducts can choke performance.

• Use 6–10” ducts, as short and straight as possible.

Tips for Proper Kitchen Ventilation in Canadian Homes

✅ Use a Ducted System (Not Recirculating)

Ductless systems don’t remove heat or moisture—just some odors.

✅ Clean or Replace Filters Regularly

Grease buildup restricts airflow and increases fire risk.

✅ Run the Hood Before and After Cooking

Start it a few minutes early and let it run 10 minutes after you finish.

✅ Maintain the Whole HVAC System

Dirty filters, leaky ducts, and poorly maintained furnaces will reduce the benefits of good kitchen ventilation.

The Canadian Connection: Why Ventilation Affects Furnace Lifespan

Back to our original question: how long should a furnace last in Canada?

The average furnace in Canada lasts 15 to 20 years—but this varies depending on:

• Moisture exposure (bad kitchen ventilation increases this)

• Filter clogging frequency

• House pressurization issues

In Martha’s case, she not only upgraded her vent hood but also added a makeup air damper. Her furnace started running more efficiently, her indoor air quality improved, and her windows stopped fogging. Best of all? Her heating bills dropped.

Conclusion: Build a Kitchen That Works With Your Furnace

The key takeaway? Your kitchen’s vent hood isn’t just about smells—it’s a critical HVAC component. If it’s not sized and balanced properly, it can make your furnace work harder, reduce comfort, and cost you more in the long run.

So, whether you’re remodeling your kitchen or just updating appliances, don’t overlook ventilation. Think airflow, balance, and above all—teamwork between your hood and your HVAC system.

FAQs

1. What is the ideal CFM for a kitchen range hood in Canada?

It depends on your stove type. A good rule of thumb: 100 CFM per linear foot for electric, and 150 for gas ranges.

2. Is a makeup air system necessary in Canadian homes?

Yes, especially if your vent hood is over 400 CFM. Many provinces require it by building code to prevent air pressure imbalances.

3. Can a range hood affect my furnace?

Absolutely. A strong vent hood can depressurize the home, affecting furnace combustion and airflow, especially in tightly built Canadian homes.

4. Do recirculating hoods work for serious cooking?

Not really. They don’t remove heat or moisture, only some odors, and are best for low-use kitchens or condos.

5. How do I know if my kitchen is properly ventilated?

Check for signs like condensation on windows, lingering odors, and excessive dust. An HVAC specialist can also test airflow.

6. Can poor ventilation reduce furnace lifespan?

Yes. Excess humidity and grease particulates can stress the furnace filter and cause corrosion over time.

7. What kind of duct should I use for my range hood?

Use rigid, smooth-walled metal ducting, ideally 6–10 inches in diameter, with minimal bends.