Top Mistakes to Avoid When Installing a Make-Up Air Unit

The Top Mistakes to Avoid When Installing a Make-Up Air Unit in Massachusetts Homes

Poor indoor air quality isn’t just uncomfortable—it can also lead to long-term issues for your home and health. In Massachusetts, where homes are sealed tightly to conserve heating and cooling energy, installing a make-up air unit becomes especially important. Yet, many homeowners rush through the installation process, leading to costly mistakes they regret later. Understanding how to install make up air for range hood systems efficiently is critical to reaping the full benefits.

Let’s explore the most common missteps and how you can avoid them when installing make-up air in your home.

Ignoring Local Building Codes and Energy Requirements

Massachusetts has some of the most progressive building standards in the country, particularly when it comes to ventilation and indoor air quality. Failure to comply with these not only risks code violations but could also reduce the efficiency of your new system.

Understand Massachusetts-Specific Ventilation Codes

Before installing any equipment, check how your project aligns with Massachusetts building codes related to mechanical ventilation. Make-up air systems often fall under energy and exhaust regulations, especially in kitchens.

• Smoke and grease-producing appliances typically require dedicated make-up air
• Range hoods over 400 CFM usually must be paired with a make-up air system
• Backdraft dampers might be required for compliance

According to the Massachusetts Residential Code, range hoods exhausting more than 400 CFM must include a make-up air system that automatically activates when the fan is on.

Make Sure to Account for Mass Save® Guidelines

Homeowners in Massachusetts may be eligible for rebates or efficiency incentives through programs like Mass Save®, but only if the system meets specific requirements.

• Ensure the equipment is rated for energy efficiency
• Submit the proper documentation post-installation
• Choose models that integrate well with energy incentives

Choosing the Wrong Size or Placement for Your Make-Up Air Unit

Many homeowners underestimate the importance of choosing the correct size and location for their air unit. Oversizing leads to energy waste and discomfort, while undersizing makes it ineffective.

Match the Unit Size to Your Exhaust System

To optimize airflow exchange, your make-up air unit must balance exactly—or almost exactly—what your kitchen vent hood removes. This becomes critical in homes where powerful range hoods are used.

• Measure range hood CFM to determine airflow needs
• Align make-up air unit CFM to within 10% of exhaust output
• Consider total home ventilation load if multiple exhaust fans exist

Oversizing a make-up air unit by just 20% can lead to drafty kitchens, elevated heating bills, and inconsistent indoor temperatures during Massachusetts winters.

Placement Matters More Than You Think

Where you position your make-up air intake impacts not only efficiency but also comfort. Cold outdoor air rushing in near high-use areas like dining rooms or bedrooms can cause discomfort, especially in winter.

• Avoid placements close to seating or food prep areas
• Integrate with HVAC ductwork for even air distribution
• Install air tempering devices if near exterior walls

This is an ideal point to consider your home's broader energy landscape. If your kitchen range isn’t the only part of your home creating ventilation challenges, it may be time to look at a more holistic solution.

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Skipping Proper Ducting and Dampers

A mistake as simple as poor ducting can cancel out the benefits of your new system. Homeowners often assume that adding a return vent is enough—which leads to inefficient airflow and pressure issues over time.

Use Proper Duct Sizes and Materials

When planning make up air installation, your duct system should match the airflow specs of your unit—not just fit in available wall space.

• Use smooth-walled metal ducts, not flexible plastic ones
• Match duct diameter to CFM requirements of the unit
• Keep duct runs as short and straight as possible to reduce resistance

Always Install Automatic Dampers

Dampers are critical components that prevent unwanted air intrusion when the system is off. In Massachusetts, a backdraft of cold winter air can quickly undermine your heating system.

• Choose motorized dampers that activate with the range hood
• Install dampers with built-in seals to prevent energy loss
• Regularly test damper function seasonally

A duct without a functioning damper can result in cold air leakage equivalent to leaving a small window open all winter long in your kitchen.

Forgetting to Temper Incoming Air in Cold Months

Massachusetts winters can be brutally cold. Bringing in untreated outdoor air through a make-up system leads to not only discomfort but potential condensation issues in your ductwork and living spaces.

Why Air Tempering Is Essential

When temperatures drop below freezing, letting that air flow into your kitchen creates a blast of cold that can chill occupants and lower indoor temperature.

• Air that's not conditioned can cause ducts to freeze
• May lead to moisture condensation and mold
• Heating systems have to work harder to compensate

Adding a heating element—or choosing a model with built-in tempering—can dramatically increase both comfort and effectiveness.

Options for Tempering Make-Up Air

There are multiple ways to warm up incoming make-up air before it enters your home:

• Electric duct heaters
• Hydronic coils connected to a boiler or water heater
• Heat recovery ventilators (HRVs) for energy efficiency

Many homeowners in Massachusetts are also exploring air-source heat pumps for broader home heating and cooling solutions that can integrate with their ventilation goals.

Not Testing System Performance After Installation

Think you’re done once the system is sealed? Not so fast. If you don't test how well the unit balances pressure and airflow, you might end up with new issues instead of solving the old ones.

Test for Balanced Air Pressure

After connecting your make up air unit installation, run tests to make sure there’s no negative pressure pulling in air from unwanted places like chimneys or attics.

• Use a smoke pen to check airflow direction
• Monitor home humidity and temperature for irregular shifts
• Run exhaust and make-up system simultaneously to validate airflow balance

Verify Indoor Air Quality Post-Installation

Once installed, your system should lead to cleaner, more breathable indoor air—especially important for families dealing with asthma or allergies.

• Check for reduced cooking odors lingering after meals
• Notice less condensation inside windows during the winter
• Confirm your home feels more comfortable during high-usage times like holidays or dinner parties

Properly installed make-up air units not only preserve your kitchen’s comfort, but can also extend the life of your appliances and HVAC systems by reducing strain.

Final Thoughts

Installing a make-up air unit is one of the smartest ways to improve kitchen ventilation and indoor comfort, especially in air-tight, energy-efficient Massachusetts homes. But getting it right requires attention to details many homeowners overlook—proper sizing, Massachusetts code compliance, smart ducting, air tempering, and post-installation testing.

Avoid shortcuts and think of this as an investment into your home’s long-term value and comfort. When installed correctly, a make-up air unit allows you to enjoy the full benefits of your range hood without the downside of uncomfortable drafts, negative pressure, or sky-high heating bills.

Take the time to plan carefully, and your home will return the favor in comfort and energy savings for years to come.