What Is Make-Up Air for a Range Hood? Why It Matters

Understanding Make-Up Air

So, what is make-up air for a range hood?
It’s the fresh, outside air brought into your home to replace the air your range hood exhausts. Without this replacement air, your kitchen exhaust system can create pressure imbalances in your home’s airflow.

Why Negative Air Pressure Is a Problem in Your Home

When your range hood removes air and it’s not replenished, it creates negative air pressure. This can lead your home to pull air from unwanted sources to equalize the pressure, causing…

• Drafts from windows, doors, or fireplaces
• Smoke, odors, or exhaust being pulled back into your home
• Strain on your HVAC system and higher energy bills
• Poor airflow that impacts your range hood’s performance

Legal Requirements for Make-Up Air Systems

In some areas, make-up air is legally required by building codes. Whether or not you need it depends on how powerful your range hood is and where you live.

Code Compliance

Many building codes mandate a make-up air system if your range hood exceeds 400 CFM (cubic feet per minute). These systems maintain indoor air quality and prevent pressure issues, especially in modern, tightly sealed homes. If you're remodeling or installing a new hood, check your range hood’s CFM rating and make sure you're compliant with the required thresholds.

Local Requirements

Certain cities, counties, or states may enforce stricter codes, especially in apartments, condos, or energy-efficient homes. Always verify your local ventilation and range hood exhaust requirements before installation to avoid project delays or failed inspections.

How Make-Up Air Systems Work

Make-up air systems bring in fresh air when your range hood is running. Here’s how they work depending on your system:

Passive Systems

A passive system uses natural airflow to bring in outside air through a dedicated duct. A damper opens when your range hood turns on, letting fresh air in without any motors or fans.

Powered Systems

Powered systems use a fan or blower to actively pull fresh air into your home. These systems are more effective in tightly sealed houses or those with high-CFM range hoods.

Integrated HVAC Systems

Some homes have make-up air integrated into their HVAC system. This routes the replacement air through your heating or cooling system to condition it before it enters your home, improving comfort and air quality.

Signs Your Kitchen Might Need Make-Up Air

If your range hood is creating airflow problems, your home will usually show it. If you notice any of the following signs, you may need a make-up air system:

• Doors that slam shut or are hard to open when the hood is running
• Drafts coming from windows, vents, or fireplaces
• Lingering cooking odors, even with the fan on
• Backdrafting from appliances like water heaters or fireplaces
• A whistling, rattling, or banging noise in your ductwork
• Poor range hood performance or weak airflow

Installation Considerations for Your Make-Up Air System

Before installing a make-up air system in your kitchen, consider the following:

• Hood size and CFM rating: Higher CFM hoods are more likely to require make-up air
• Home airtightness: Newer, energy-efficient homes may need added ventilation support
• Damper placement: The damper should open and close in sync with your range hood
• Air intake location: Fresh air should come from a clean, safe source away from pollutants
• Duct routing and insulation: Properly sealed, insulated ducts help maintain comfort and airflow
• Conditioning the air: In hot or cold climates, bringing in unfiltered outdoor air can affect comfort

Invest in Safe Ventilation with FOTILE Range Hoods

Before you upgrade your range hood, make sure your kitchen has the airflow it needs. FOTILE hoods provide strong, reliable ventilation to keep your home comfortable, quiet, and safe.

Browse our full collection of range hoods to find the perfect fit for your home.