Airflow CFM: Ventilation Guide for US Homes

For homeowners aiming to enhance indoor air quality and comfort, understanding airflow cubic feet per minute (airflow cfm) is essential, and the Home Ventilating Institute (HVI) provides valuable resources for determining appropriate ventilation rates. Calculating airflow cfm requirements often involves using tools like an anemometer to measure air velocity through ductwork. Furthermore, ASHRAE Standard 62.2 sets the benchmark for residential ventilation, influencing how airflow cfm is determined for various home sizes. For example, a typical home in Atlanta may have different airflow cfm requirements compared to one in Seattle due to variations in climate and building codes.

Breathing Easy: Why Residential Ventilation Matters

The air within our homes, often unseen and unconsidered, plays a pivotal role in our health, comfort, and the very longevity of our dwellings. Residential ventilation, the process of replacing stale indoor air with fresh outdoor air, is not merely an amenity; it is a fundamental necessity for a healthy and sustainable living environment.

The Imperative of Indoor Air Quality

Modern homes, designed for energy efficiency, are often tightly sealed. While this reduces energy consumption, it also traps pollutants, allergens, and moisture inside.

These contaminants can include volatile organic compounds (VOCs) from cleaning products and furnishings, radon gas from the ground, and particulate matter from cooking and outdoor sources.

Insufficient ventilation allows these pollutants to accumulate, leading to a range of adverse health effects, from respiratory problems and allergies to headaches and fatigue.

Proper ventilation is the primary defense against this build-up, diluting indoor pollutants and maintaining acceptable air quality.

Ventilation: A Cornerstone of Well-being

The connection between good ventilation and overall well-being is undeniable. Fresh air promotes better sleep, improved cognitive function, and reduced stress levels.

Adequate ventilation also helps control humidity, preventing mold growth and dust mite infestations, both of which can exacerbate allergies and respiratory issues.

By ensuring a constant supply of fresh air, ventilation creates a more comfortable and healthy living environment for all occupants.

The Synergy of Energy Efficiency and Ventilation

While tightly sealed homes can save energy, they can also compromise indoor air quality. However, energy efficiency and proper ventilation are not mutually exclusive.

Modern ventilation systems, such as Heat Recovery Ventilators (HRVs) and Energy Recovery Ventilators (ERVs), are designed to exchange air while minimizing energy loss.

These systems recover heat or cool energy from the outgoing air and transfer it to the incoming fresh air, significantly reducing heating and cooling costs.

By integrating energy-efficient ventilation solutions, homeowners can achieve both superior indoor air quality and reduced energy consumption.

Preserving the Structural Integrity of Buildings

Beyond health and energy efficiency, ventilation plays a vital role in preserving the structural integrity of buildings.

Excessive moisture, a common byproduct of daily activities like cooking and showering, can lead to wood rot, corrosion, and other forms of structural damage.

Proper ventilation helps control moisture levels, preventing these problems and extending the lifespan of the building.

By addressing these core concepts, understanding essential equipment, and adhering to regulations, homeowners can ensure a healthy, comfortable, and sustainable living environment through effective residential ventilation.

Core Concepts Unveiled: Understanding Airflow, ACH, and More

Before delving into the specifics of ventilation equipment and regulations, it's crucial to establish a firm understanding of the fundamental principles that govern airflow and air quality within a residential setting. Grasping these core concepts will empower homeowners and professionals alike to make informed decisions about ventilation strategies.

Airflow: The Breath of a Building

At its most basic, airflow refers to the movement of air from one location to another. In the context of residential ventilation, airflow is the engine that drives the removal of stale, polluted indoor air and its replacement with fresh, cleaner air from the outdoors.

Without adequate airflow, pollutants can accumulate, leading to poor indoor air quality and potential health problems. Think of it as a river: a stagnant river breeds algae and disease, while a flowing river remains clean and healthy.

Effective ventilation ensures a continuous and controlled exchange of air, preventing the build-up of harmful contaminants.

Ventilation Types: Exhaust, Supply, and Balanced

Residential ventilation systems can be broadly categorized into three main types: exhaust, supply, and balanced. Each approach has its own strengths and weaknesses, and the optimal choice depends on the specific needs of the home.

Exhaust Ventilation

Exhaust ventilation systems work by extracting stale air from inside the home and expelling it outdoors. Common examples include bathroom fans, kitchen range hoods, and laundry room vents.

These systems create negative pressure within the home, drawing in outdoor air through leaks in the building envelope.

While relatively simple and inexpensive to install, exhaust ventilation can lead to drafts and energy loss if the building is not properly sealed.

Supply Ventilation

In contrast, supply ventilation systems force fresh outdoor air into the home, creating positive pressure. This positive pressure forces stale indoor air out through leaks in the building envelope.

Supply ventilation systems often include filtration to remove pollutants from the incoming air, offering a significant advantage in areas with poor outdoor air quality.

However, like exhaust ventilation, supply ventilation can also create drafts and increase energy costs if not properly managed.

Balanced Ventilation

Balanced ventilation systems, such as Heat Recovery Ventilators (HRVs) and Energy Recovery Ventilators (ERVs), aim to provide both supply and exhaust ventilation in equal measure. This approach minimizes pressure imbalances and drafts.

HRVs and ERVs also incorporate heat exchangers that transfer heat between the incoming and outgoing air streams, significantly improving energy efficiency.

While more complex and expensive to install, balanced ventilation offers the most comprehensive and energy-efficient solution for maintaining good indoor air quality.

Air Changes per Hour (ACH): Quantifying Ventilation Effectiveness

Air Changes per Hour (ACH) is a metric used to quantify the rate at which the air in a building is replaced with fresh air.

It represents the number of times the entire volume of air within a space is replaced in one hour. A higher ACH indicates more effective ventilation.

ACH is calculated by dividing the ventilation rate (in cubic feet per minute, or CFM) by the volume of the space (in cubic feet) and then multiplying by 60.

While ACH provides a useful benchmark, it's important to note that the ideal ACH varies depending on factors such as occupancy levels, activity levels, and the presence of specific pollutants.

Static Pressure: Understanding Resistance to Airflow

Static pressure is the force exerted by air against the walls of a duct or enclosure. In ventilation systems, static pressure reflects the resistance to airflow caused by factors such as ductwork design, filters, and dampers.

Excessive static pressure can significantly reduce airflow, diminishing the effectiveness of the ventilation system. Measuring static pressure with a manometer can help identify areas of restriction and optimize system performance.

Proper duct sizing and regular filter maintenance are crucial for minimizing static pressure and maintaining optimal airflow.

Infiltration and Exfiltration: The Uncontrolled Exchange

Infiltration refers to the uncontrolled flow of outdoor air into a building through cracks, gaps, and other unintentional openings in the building envelope.

Exfiltration, conversely, is the uncontrolled flow of indoor air out of the building. Both infiltration and exfiltration can have significant impacts on energy efficiency and indoor air quality.

Excessive infiltration can lead to drafts, increased heating and cooling costs, and the introduction of outdoor pollutants. Excessive exfiltration can draw in air from undesirable locations, such as crawl spaces or attics.

Air sealing measures, such as caulking and weatherstripping, are essential for minimizing infiltration and exfiltration and maintaining a tight building envelope.

Real-World Ventilation Scenarios

To illustrate these concepts in practice, consider a few relatable scenarios:

• The Steamy Bathroom: After a hot shower, the bathroom air is saturated with moisture. An exhaust fan removes this moisture-laden air, preventing mold growth and maintaining a comfortable humidity level. This demonstrates exhaust ventilation in action.
• The Overcrowded Living Room: During a party, the air in the living room becomes stale and stuffy due to the presence of many people. Opening windows to increase airflow helps to replenish the oxygen supply and remove pollutants.
• The Newly Renovated Home: After installing new windows and doors, a homeowner notices that the house feels stuffier and that condensation is forming on the windows. This is likely due to reduced infiltration, highlighting the need for a dedicated ventilation system to compensate.

By understanding these core concepts, homeowners and professionals can make informed decisions about ventilation strategies and ensure a healthy, comfortable, and energy-efficient indoor environment.

Essential Equipment: Your Ventilation Toolkit

[Core Concepts Unveiled: Understanding Airflow, ACH, and More Before delving into the specifics of ventilation equipment and regulations, it's crucial to establish a firm understanding of the fundamental principles that govern airflow and air quality within a residential setting. Grasping these core concepts will empower homeowners and professionals...]

Effective residential ventilation relies on a variety of equipment working in concert. Selecting the right tools for the job is paramount to achieving optimal indoor air quality and energy efficiency. Let's examine the key components of a comprehensive ventilation system, dissecting their functions and highlighting their contributions.

The Cornerstone: Exhaust Fans

Exhaust fans are among the most ubiquitous ventilation devices found in homes. Their primary function is to remove stale, humid air and pollutants from specific areas.

Bathroom Exhaust Fans: These are essential for controlling moisture buildup after showers and baths. Excessive humidity can lead to mold growth and structural damage. Ensure the fan is properly sized for the bathroom's square footage and is vented to the outdoors, not just into the attic.

Laundry Room Exhaust Fans: Laundry rooms generate significant moisture and lint. An exhaust fan helps prevent these from accumulating, protecting air quality and preventing potential fire hazards.

Kitchen Ventilation: The Range Hood Imperative

The kitchen is a major source of indoor air pollutants, including smoke, grease, and combustion byproducts. A range hood is crucial for capturing these contaminants at the source.

Types of Range Hoods: Choose between ducted models that vent outside or ductless models that filter the air. Ducted range hoods are generally more effective at removing pollutants, while ductless models offer easier installation.

CFM Rating: Select a range hood with an adequate CFM (cubic feet per minute) rating based on the size and type of your cooking appliances. A higher CFM is necessary for gas stoves and frequent, high-heat cooking.

Whole-House Fans: A Blast of Fresh Air

Whole-house fans offer a powerful means of rapidly ventilating an entire home. They work by drawing cool, outdoor air in through open windows and exhausting warm, stale air into the attic.

Strategic Operation: These fans are most effective during cooler evenings and mornings when the outdoor air temperature is lower than the indoor temperature. Properly used, they can significantly reduce reliance on air conditioning.

Installation Considerations: Ensure the attic is adequately vented to prevent pressure buildup and potential damage.

HVAC Systems: More Than Just Heating and Cooling

While primarily designed for heating and cooling, HVAC (Heating, Ventilation, and Air Conditioning) systems also play a role in ventilation.

Forced-Air Systems: Forced-air systems can introduce fresh air into the home through a dedicated fresh air intake. However, it's crucial to ensure the system is properly balanced and maintained to avoid negatively impacting energy efficiency.

BTU Sizing: It is critical to properly size the system for the house. Systems that are too small will run constantly, and systems that are too large will cool too rapidly and not adequately remove humidity.

Balanced Ventilation: HRVs and ERVs

Heat Recovery Ventilators (HRVs) and Energy Recovery Ventilators (ERVs) provide balanced ventilation, simultaneously exhausting stale indoor air and supplying fresh outdoor air.

Heat Recovery: HRVs transfer heat from the outgoing air to the incoming air, reducing energy consumption during the heating season.

Energy Recovery: ERVs transfer both heat and moisture, helping to maintain humidity levels and reduce energy consumption year-round. ERVs are particularly beneficial in humid climates.

Duct Boosters: Enhancing Airflow

Duct boosters are inline fans that can be installed in ductwork to improve airflow in specific areas of the home.

Addressing Airflow Issues: These fans can be useful for boosting airflow to rooms that are far from the HVAC unit or that have long, restrictive duct runs.

Careful Application: Using duct boosters effectively requires careful consideration of the existing ductwork and the overall system design. Overuse or improper installation can create imbalances and reduce overall system efficiency.

Tools of the Trade: Assessing and Optimizing Your Ventilation

[Essential Equipment: Your Ventilation Toolkit [Core Concepts Unveiled: Understanding Airflow, ACH, and More Before delving into the specifics of ventilation equipment and regulations, it's crucial to establish a firm understanding of the fundamental principles that govern airflow and air quality within a residential setting. Grasping these core con...]

While understanding ventilation principles and selecting the right equipment are paramount, effectively assessing and optimizing a ventilation system requires specialized tools. These instruments allow professionals to diagnose problems, fine-tune performance, and ensure that the system operates as intended. Let's explore the essential tools used in the trade and how they contribute to creating healthier and more efficient indoor environments.

Measuring Air Velocity: The Anemometer

The anemometer is a fundamental tool for measuring air velocity, typically expressed in feet per minute (FPM). It's used to determine the speed of airflow at registers, grilles, and within ductwork.

By measuring air velocity at different points in the system, professionals can identify areas where airflow is restricted or inadequate.

Different types of anemometers exist, including vane anemometers (also known as rotating anemometers) and hot-wire anemometers. Vane anemometers are suitable for measuring air velocity through larger openings, while hot-wire anemometers are more precise for measuring lower air velocities.

Static Pressure Diagnostics: The Manometer

A manometer measures static pressure, which is the pressure exerted by air within a duct or system. It is typically measured in inches of water column (in. w.c.).

Excessive static pressure indicates resistance to airflow, which can lead to reduced ventilation effectiveness and increased energy consumption.

A manometer connects to the ductwork via a small hole, and the pressure reading indicates the resistance the air encounters. Professionals use manometers to identify obstructions, undersized ducts, or other issues that impede airflow.

Air Balancing: Dampers and Registers

Air balancing involves adjusting dampers and registers to ensure that the correct amount of airflow is delivered to each room or area. This is crucial for maintaining consistent temperatures and air quality throughout a home.

Specialized tools, such as balancing dampers and airflow hoods, are used to measure and adjust airflow to meet design specifications. Balancing dampers, typically located within ductwork, restrict or increase airflow to specific zones. Registers, the vents you see in rooms, can also be adjusted to fine-tune airflow distribution.

Visualizing Airflow Patterns: Smoke Sticks and Pencils

Smoke sticks or pencils release a small amount of visible smoke, allowing professionals to visualize airflow patterns.

This technique is particularly useful for identifying drafts, leaks, and areas where air is not circulating properly.

By observing the movement of the smoke, professionals can gain insights into how air is entering, moving within, and exiting a space, helping to pinpoint ventilation deficiencies.

Determining Air Volume: Airflow Meters

Airflow meters, also known as flow hoods or balometers, measure the volume of air moving through a vent or register, typically expressed in cubic feet per minute (CFM).

CFM is a critical metric for determining whether a ventilation system is meeting its design specifications.

Airflow meters are placed over the vent to capture and measure the air flowing through it. This information is essential for verifying that the system is delivering the correct amount of ventilation to each area.

Ensuring Proper Ductwork: Duct Sizing Calculators

Duct sizing calculators are tools, often software-based, used to determine the appropriate dimensions of ductwork based on airflow requirements, static pressure, and other factors.

Proper duct sizing is essential for efficient ventilation.

Undersized ducts can restrict airflow, while oversized ducts can lead to energy waste. Duct sizing calculators help professionals design ductwork systems that meet the specific needs of a building.

Estimating Ventilation Needs: CFM Calculators

CFM calculators are used to estimate the required airflow rate (CFM) for a particular space based on factors such as room size, occupancy, and activity level.

These calculators help ensure that ventilation systems are adequately sized to meet the needs of the occupants. They provide a starting point for designing or evaluating ventilation systems, helping professionals to determine the appropriate equipment and settings.

Putting it All Together: Identifying Problems and Optimizing Performance

By using these tools effectively, ventilation professionals can identify a range of problems, including:

• Inadequate Airflow: Anemometers and airflow meters can reveal areas where airflow is below the required level.
• Excessive Static Pressure: Manometers can detect high static pressure, indicating ductwork obstructions or undersizing.
• Imbalanced Airflow: Air balancing tools can identify rooms that are receiving too much or too little airflow.
• Drafts and Leaks: Smoke sticks can reveal areas where air is entering or exiting the building unintentionally.

By addressing these issues, professionals can optimize ventilation system performance, ensuring that the system delivers the right amount of fresh air to each area, removes pollutants effectively, and operates efficiently.

Ventilation Professionals: Who to Call for Expert Help

After mastering the tools and techniques for assessing your home's ventilation, knowing who to call for professional assistance is the next critical step. Residential ventilation is a multifaceted field, and different specialists bring unique expertise to the table. Understanding their roles ensures you engage the right professional for your specific needs, saving you time, money, and potential headaches.

HVAC Contractors: Installation, Maintenance, and Repair Specialists

HVAC (Heating, Ventilation, and Air Conditioning) contractors are often the first point of contact for ventilation-related issues.

Their primary role is the installation, maintenance, and repair of HVAC systems, including those components directly contributing to ventilation.

Core Services

• System Installation: They install ventilation equipment, ensuring proper sizing, placement, and ductwork connections.

• Routine Maintenance: They provide scheduled maintenance to keep systems running efficiently and prevent breakdowns.

• Repairs and Troubleshooting: They diagnose and repair ventilation problems, addressing issues like fan malfunctions or duct leaks.

When to Call an HVAC Contractor

Engage an HVAC contractor when you need new ventilation equipment installed, suspect problems with your existing system, or require routine maintenance.

They are particularly valuable when dealing with ducted systems, HRVs/ERVs, or complex HVAC setups.

Home Inspectors: Ventilation System Evaluators

Home inspectors play a vital role during real estate transactions, but their expertise extends beyond just identifying structural issues.

They evaluate ventilation systems as part of a comprehensive home inspection, identifying potential problems that could impact air quality and building health.

Scope of Inspection

• Exhaust Fan Functionality: They check for proper operation and airflow in bathroom and kitchen exhaust fans.

• Ventilation Adequacy: They assess whether the home meets minimum ventilation requirements based on local codes.

• Moisture Issues: They look for signs of moisture buildup, which can be exacerbated by poor ventilation.

When to Call a Home Inspector

Home inspectors are essential during the purchase or sale of a home. Their report can highlight ventilation deficiencies that need to be addressed, protecting both buyers and sellers.

Energy Auditors: Experts in Performance and Efficiency

Energy auditors take a holistic approach to home performance, evaluating energy efficiency and identifying opportunities for improvement.

Ventilation plays a crucial role in energy efficiency, and energy auditors can assess its impact on heating and cooling costs.

Assessment Process

• Blower Door Tests: They use blower door tests to measure air leakage and identify areas where infiltration can be reduced.

• Thermal Imaging: They use thermal imaging to detect insulation gaps and air leaks.

• Ventilation Analysis: They evaluate the effectiveness of the ventilation system and recommend upgrades.

When to Call an Energy Auditor

Consult an energy auditor if you want to reduce your energy bills, improve indoor air quality, and enhance the overall comfort of your home.

They can provide valuable insights and recommendations for optimizing your ventilation system.

Building Scientists: Applying Scientific Principles to Building Performance

Building scientists possess specialized knowledge of how buildings function as systems.

They understand the complex interactions between ventilation, insulation, moisture control, and other factors that impact building performance.

Areas of Expertise

• Indoor Air Quality Analysis: They can conduct thorough IAQ assessments and identify sources of pollutants.

• Moisture Management: They develop strategies to prevent moisture buildup and mold growth.

• Ventilation System Design: They can design custom ventilation systems tailored to specific building needs.

When to Call a Building Scientist

Engage a building scientist when dealing with complex ventilation challenges, persistent indoor air quality problems, or moisture-related issues.

Their expertise can help you develop comprehensive solutions that address the root causes of these problems.

Engineers: Designing for Efficiency and Effectiveness

Engineers are involved in the design and specification of HVAC and ventilation systems, particularly in new construction or major renovations.

They apply their technical knowledge to create systems that meet specific performance requirements while adhering to building codes and standards.

Engineering Design Process

• Load Calculations: They perform load calculations to determine the heating and cooling requirements of the building.

• System Sizing: They select the appropriate size and type of ventilation equipment.

• Ductwork Design: They design ductwork systems to ensure proper airflow and minimize pressure drops.

When to Call an Engineer

Consult an engineer when designing a new home, undertaking a major renovation, or when requiring a highly customized ventilation solution.

Their expertise ensures that the system is properly designed and installed for optimal performance.

Selecting the right professional for your ventilation needs requires careful consideration of the project scope and complexity. By understanding the unique skills and expertise of each type of specialist, you can make informed decisions and ensure a healthy, comfortable, and energy-efficient home.

Legal and Regulatory Landscape: Navigating Ventilation Codes and Standards

Ventilation Professionals: Who to Call for Expert Help After mastering the tools and techniques for assessing your home's ventilation, knowing who to call for professional assistance is the next critical step. Residential ventilation is a multifaceted field, and different specialists bring unique expertise to the table. Understanding their roles ensures you receive the right support for your specific needs. However, beyond expertise lies the critical framework of regulations that governs ventilation practices.

Navigating the legal and regulatory landscape surrounding residential ventilation can seem daunting, but it's a crucial aspect of ensuring a healthy, safe, and energy-efficient home. Building codes, indoor air quality standards, and energy efficiency standards all play a significant role in shaping ventilation requirements. Ignoring these regulations can lead to legal repercussions, compromised indoor air quality, and increased energy costs.

The Foundation: Building Codes and Minimum Ventilation

Building codes form the bedrock of ventilation regulations. These codes, typically adopted and enforced at the state or local level, specify minimum ventilation rates and requirements for new construction and renovations. They often mandate the installation of exhaust fans in bathrooms and kitchens, as well as whole-house ventilation systems in tightly sealed homes.

These requirements are not arbitrary; they are designed to ensure adequate fresh air supply and the removal of pollutants generated within the home. Compliance with building codes is essential for obtaining permits and ensuring the safety and habitability of a dwelling.

Local building codes often reference established standards, such as those developed by the International Code Council (ICC). The ICC's International Residential Code (IRC) provides detailed guidance on ventilation requirements, including:

• Minimum exhaust rates for different rooms.
• Acceptable methods for providing whole-house ventilation.
• Requirements for make-up air.
• HRV or ERV installation guidelines.

It's important to note that building codes are frequently updated to reflect the latest research and best practices in ventilation and energy efficiency. Consulting with a local building official or a qualified HVAC professional is crucial to ensure compliance with the most current requirements.

Protecting Occupants: Indoor Air Quality Standards

While building codes focus on minimum ventilation rates, indoor air quality (IAQ) standards provide a broader framework for protecting occupants from harmful pollutants. These standards, often developed by organizations like the Environmental Protection Agency (EPA) and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), offer guidelines and recommendations for maintaining healthy indoor air.

The EPA provides comprehensive information on common indoor air pollutants, their health effects, and strategies for mitigation. Their resources include:

• Guidance on controlling sources of pollution.
• Recommendations for improving ventilation.
• Information on air cleaning devices.
• Tips for maintaining healthy humidity levels.

ASHRAE Standard 62.2, Ventilation and Acceptable Indoor Air Quality in Residential Buildings, is a widely recognized industry standard that specifies minimum ventilation rates and other requirements for achieving acceptable IAQ. It provides a more detailed and technical approach to ventilation design than building codes, and is often referenced by code officials and HVAC professionals.

The key difference is the focus on health outcomes, not just minimum requirements. These standards push for proactive strategies.

The Push for Efficiency: Energy Efficiency Standards

Energy efficiency standards are increasingly intertwined with ventilation requirements. Regulations like those from the Department of Energy (DOE) set minimum energy performance standards for HVAC equipment, including ventilation systems. These standards aim to reduce energy consumption and greenhouse gas emissions while maintaining acceptable indoor air quality.

The focus on energy efficiency has led to the development and adoption of advanced ventilation technologies, such as heat recovery ventilators (HRVs) and energy recovery ventilators (ERVs). These devices recover heat or energy from exhaust air and transfer it to incoming fresh air, reducing energy losses associated with ventilation.

These standards encourage a holistic approach to building design and operation, where ventilation is integrated with other energy-saving measures to achieve optimal performance. The trend toward tighter building envelopes, designed to minimize air leakage, necessitates mechanical ventilation systems to ensure adequate fresh air supply. It is here that codes and standards have come together.

Ensuring Compliance: Why It Matters

Adhering to ventilation codes and standards is not merely a matter of legal compliance; it's an investment in the health, safety, and well-being of building occupants. Proper ventilation can:

• Reduce exposure to indoor air pollutants, such as radon, mold, and volatile organic compounds (VOCs).
• Improve respiratory health and reduce allergy symptoms.
• Enhance comfort by maintaining optimal humidity levels.
• Prevent moisture buildup and structural damage.
• Lower energy costs by optimizing HVAC system performance.

Failure to comply with ventilation regulations can result in:

• Construction delays and permit denials.
• Fines and legal penalties.
• Increased liability for property owners.
• Negative health impacts for occupants.

Navigating the regulatory landscape can be complex, but the benefits of compliance are undeniable. Consulting with qualified professionals, such as HVAC contractors, energy auditors, and building officials, is essential to ensure that your home meets all applicable requirements and provides a healthy and comfortable living environment.

So, there you have it! Hopefully, this guide helps you wrap your head around airflow CFM and how to use it to improve the ventilation in your home. Remember, a well-ventilated home is a healthier and more comfortable home. Time to put that newfound airflow CFM knowledge to good use and breathe a little easier!