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How a Make-Up Air Unit Improves Indoor Air Quality and Safety

By
Ilija Crnobrnja
June 6, 2025
7
min read
Thumbnail image thoughtfully designed to reflect the theme of this blog article.

Why Make-Up Air Units Are a Game-Changer for Massachusetts Homes

Keeping your indoor air clean and safe is crucial, especially in energy-efficient homes where air tends to stay trapped inside. For Massachusetts homeowners using range hoods or exhaust fans, a key piece of the air quality puzzle often goes unnoticed: the make-up air unit. These systems restore balance by replacing the air that’s pulled out of your home, preventing pressure issues and improving air quality in kitchens and beyond.

In this article, we’ll explore how make-up air unit installation helps protect your indoor environment, why it's particularly important in Massachusetts homes, and how to install the system the right way—safely and effectively.

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How Make-Up Air Units Solve Common Air Quality Problems

Most modern homes across Massachusetts are built to be energy efficient, with insulation that keeps heated or cooled air from escaping. The downside? Exhaust systems like range hoods, bathroom fans, and dryers can create negative pressure—sucking air out faster than it can come in.

What Is a Make-Up Air Unit?

A make-up air unit is a ventilation system designed to bring fresh outdoor air back into your home to "make up" for air that’s been exhausted. Without one, indoor pressure becomes unbalanced, and pollutants build up quickly.

Many Massachusetts homes experience air backdrafts from combustion appliances—often a result of poorly balanced ventilation systems.

Make-up air units counteract this by providing:

  • Balanced indoor air pressure
  • Improved airflow for range hoods and fans
  • Reduced risk of radon or combustion gases infiltrating living spaces
  • Better control of moisture and mold buildup

Where Air Problems Show Up Most

While poor airflow may affect the whole house, problems often start in places like:

  • Kitchens: Strong range hoods with no make-up air source can cause outside air to leak in through doors, windows, or chimneys
  • Basements: Negative pressure can pull in radon and other gases from the soil
  • Bathrooms: Exhaust fans struggle without a reliable air replacement, leading to steamy, mold-prone environments

The result? Unhealthy living conditions, especially in tight Massachusetts homes during the winter and summer months when windows stay closed.

How to Install Make-Up Air Systems in Massachusetts Homes

When it comes to improving ventilation with make-up air, homeowners often wonder how the installation process works—and where to begin. Massachusetts building codes can affect how and where you install the unit, and knowing these details helps ensure both code compliance and effectiveness.

Choosing the Right Location

Start by identifying the main air-extracting appliances in your home—most often the kitchen range hood. An effective make up air installation requires placing the intake in a location that doesn’t clash with these systems but helps balance them.

Tips for installation site selection:

  • Place the unit near the kitchen or laundry—but not in direct path of exhaust
  • Avoid pulling in air from garages or attics
  • Choose an access point through an exterior wall, ideally in a low-traffic hidden space

Equipment and Materials Needed

While specific equipment may vary based on brand, some of the most reliable systems are made by Mitsubishi Electric, Bosch HVAC, and Daikin. However, even the best unit won't help if installed improperly. Here's a general overview of what installation involves:

  1. Fresh air intake hood, mounted outside
  2. Filter and ducting system connected to intake and indoor delivery point
  3. Optional pre-heating or tempering coil to warm air in winter
  4. Smart controls to regulate when the system turns on

In cold Massachusetts winters, untempered make-up air can chill your kitchen and reduce efficiency unless properly configured.

Key Considerations for Kitchen Range Hoods

From a building code standpoint, adding an exhaust hood over 400 CFM (cubic feet per minute) often requires a make-up air system. Knowing how to install make up air for range hood appliances hinges on your hood's design and strength.

Key steps include:

  • Calculating air exhaust volume to size the make-up air system correctly
  • Routing ductwork to avoid sharp bends or long runs
  • Ensuring your heating system doesn't counteract incoming airflow
  • Adding a damper to close the system when it's not in use

Installing it properly ensures your hood performs well without causing discomfort—or violating local codes.

The Safety and Health Benefits for Massachusetts Homeowners

Beyond comfort, installing a make-up air unit directly impacts your family’s health and safety. With changing seasons and high energy demands, Massachusetts homes benefit greatly from this overlooked upgrade.

Combustion Safety

Many homes rely on fuel-burning devices like water heaters, furnaces, or fireplaces. These need plenty of oxygen to burn cleanly. Without make-up air, exhaust fans can pull air away from these systems—causing what's known as "backdrafting."

Backdrafting is dangerous because it can:

  • Draw carbon monoxide and other combustion gases into your living space
  • Interfere with pilot lights and other flame-based safeguards
  • Trigger persistent, hard-to-locate safety issues

Improved Indoor Air Quality

By continually cycling in small amounts of filtered outdoor air, make-up air systems help reduce:

  • Volatile Organic Compounds (VOCs) from cooking and cleaning
  • Moisture that leads to mold in high-humidity bathrooms or basements
  • Stagnant air, especially in homes sealed tightly for insulation purposes
According to the Environmental Protection Agency, indoor air quality is often 2 to 5 times more polluted than the air outside—even more without proper ventilation.

Energy Efficiency Upgrades Eligible for Incentives

Massachusetts residents may qualify for state efficiency programs through Mass Save®, which offers rebates on systems that improve home ventilation and air quality. Make-up air may even be included in larger energy upgrades.

Visit the Mass Save® home energy assessment page to find out eligibility details and how to get started.

Your Next Step to Safer, Cleaner Indoor Air

Installing a make-up air unit is more than a compliance measure—it’s a proactive step toward a healthier, safer, and more comfortable Massachusetts home. Whether you're upgrading your range hood, fixing airflow issues, or planning a renovation, this solution offers peace of mind, all year round.

If you're serious about improving your home's air quality and reducing safety risks, exploring make up air unit installation should be high on your list. Not only does it help your kitchen and exhaust systems run smoothly, but it also protects your entire home environment from hidden hazards.

Breathe Easier, Massachusetts — Fix Your Air

Make-up air unit installation restores healthy airflow, reduces indoor pollutants, and keeps your Massachusetts home safe and balanced—especially if you're using range hoods or exhaust fans.

Install Make-Up Air Now

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