Why Proper Ventilation in Kitchens Matters

Cooking releases more than just delicious smells. Grease, smoke, steam, and even carbon monoxide enter the air. Without a well-designed ventilation system, these pollutants accumulate quickly.

Here’s why good ventilation is critical:

• Health and Safety: Removes harmful fumes and prevents CO2 buildup.

• Comfort: Reduces heat and humidity levels.

• Cleanliness: Helps control grease and odors.

• Efficiency: Keeps HVAC systems from overworking.

In commercial kitchens, these issues are magnified. But even in home kitchens, improper ventilation can lead to mold, uneven temperatures, and HVAC strain.

How Range Hoods Impact HVAC Balance

The Vent Hood’s Role

Range hoods are the front line of defense. They capture smoke and contaminants at the source and exhaust them outdoors or filter them for recirculation. However, they also pull air out of the space, which needs to be replaced. This is where the HVAC balance comes into play.

The Tug-of-War with Air Pressure

Think of your HVAC system and range hood as two teams in a tug-of-war over air pressure. If your vent hood pulls out 1200 CFM (cubic feet per minute) of air, your HVAC system must somehow bring in 1200 CFM to replace it. If not, you create negative pressure, which can cause:

• Doors that slam shut or don’t open properly

• Outdoor air being sucked in through cracks or flues (backdrafting)

• Uneven heating and cooling throughout the building

In restaurants, this can impact dining comfort. At home, it may reduce system efficiency and increase energy bills.

Make-Up Air: The Unsung Hero

To solve the pressure imbalance, many systems use a make-up air unit (MAU). This brings in filtered, tempered outdoor air to replace the exhausted air.

Benefits of Make-Up Air Systems:

• Restores balance to HVAC airflow

• Prevents smoke and odors from re-entering the space

• Helps meet local building codes (especially in commercial setups)

Always consult local regulations—many commercial kitchens are required to have MAUs for any hood over 400 CFM.

Sizing Guidelines for Vent Hoods in HVAC Kitchens

Getting the sizing right is key to performance and energy efficiency. Here’s a simplified guide:

For Residential Kitchens:

• Standard Electric Cooktop: 150–300 CFM

• Gas Cooktop: 300–600 CFM

• High-Performance Ranges or Grills: 900+ CFM

• Rule of thumb: 100 CFM per 10 inches of range width (for wall-mounted hoods)

For Commercial Kitchens:

• Light Duty (Ovens, Steamers): 150–300 CFM per linear foot of hood

• Medium Duty (Ranges, Fryers): 300–500 CFM per linear foot

• Heavy Duty (Charbroilers, Woks): 500–700+ CFM per linear foot

• Always include duct length, hood type, and external fan resistance in your calculations.

Don’t forget to calculate the make-up air requirement to match the exhaust rate. An HVAC professional or mechanical engineer should perform a full system analysis for best results.

Real-World Story: When Ventilation Goes Wrong

Take “La Riviera,” a trendy bistro in a downtown high-rise. They had a top-tier kitchen range hood, but no make-up air system. Guests started noticing smoky air during dinner service. Employees complained of headaches and the HVAC bills kept rising.

After calling in an HVAC specialist, they discovered their range hood was pulling more air than the building could replace. Negative pressure was drawing in dirty air from the garage below. A properly sized make-up air system solved the problem overnight—cleaner air, better comfort, and a big drop in energy costs.

Conclusion: Balance Is Everything

When designing or upgrading a kitchen—whether at home or in a restaurant—it’s tempting to focus on flashy ranges or sleek hoods. But behind the scenes, the balance between your vent hood and HVAC system is critical. With the right ventilation plan, proper sizing, and make-up air integration, you can ensure a safer, more comfortable, and more efficient cooking environment.

FAQs

1. What does a vent hood do in HVAC kitchens?

It removes smoke, grease, steam, and odors from cooking areas, preventing air contamination and heat buildup.

2. What is make-up air, and why do I need it?

Make-up air replaces the air your vent hood exhausts. Without it, you may experience negative pressure, leading to HVAC inefficiency and backdrafts.

3. Can I install a 900+ CFM hood at home without issues?

Yes, but you must include make-up air or recirculation to maintain pressure balance. Local codes often require this for hoods over 400 CFM.

4. Do range hoods affect heating and cooling performance?

Absolutely. Oversized or unbalanced systems can overwork your HVAC, reduce lifespan, and increase energy bills.

5. What happens if my hood is undersized?

It won’t effectively remove heat, smoke, or grease, leading to poor air quality and higher cleaning costs.

6. Are ductless range hoods good for HVAC balance?

They don’t exhaust air, so they don’t impact pressure directly—but they also don’t remove heat or moisture. They’re best for supplemental use.

7. Can I run my vent hood and AC at the same time?

Yes, but ensure your system is balanced with proper airflow and make-up air to avoid performance issues.

8. Who should size my kitchen ventilation system?

For homes, an HVAC contractor is sufficient. For commercial kitchens, consult a mechanical engineer with experience in ventilation design.