Like most homeowners, you probably know you should change your air filter periodically. Most HVAC professionals recommend replacing it every three months. But are you choosing the correct MERV rating for your home and lifestyle?
“What’s a MERV rating? And what MERV rating do I need?” you might ask. As Glastonbury’s reliable HVAC company, our technicians at SM Mechanical Services provide answers. We also offer guidance on choosing the best rating for your needs below.
What Is Indoor Air Quality?
First, explore indoor air quality and how it affects your life. Indoor air quality refers to the air circulating throughout a building. Air quality can affect occupants’ health and comfort. It can even influence the building’s structures.
Air Quality Influences
A broad range of factors can influence your indoor air quality, lifestyle, and habits. Some elements, like pollen, pollution, or moisture infiltrating your home, are beyond your control. However, you might recognize the following examples within your living room:
- Candles, incense, and other scented items
- Smoking cigarettes or vaping
- Microbes and mold
- Dust and dirt
- Building materials
- Humidity
- HVAC maintenance
- Ventilation
How Indoor Air Quality Affects You
Can each particle and pollutant affect your comfort and health? It can and will! The particles listed above can severely impact your respiratory health, as your lungs draw in oxygen and deliver it to the rest of your body.
Your oxygen levels affect various health aspects, including:
- Energy levels
- Inflammation
- Sleep cycles
- Mental health
If you constantly feel fatigued or struggle with a never-ending allergy infection, you can probably blame poor indoor air quality.
What Is a MERV Rating?
Now that you know more about indoor air quality, you can better understand the purpose of MERV (Minimum Efficiency Reporting Value) ratings. MERV ratings inform consumers about the particle sizes your system’s filters will capture and remove from air circulation.
Higher MERV ratings capture small, elusive particles. Low ratings allow smaller particles to pass through the filter fibers.
How Many Ratings Are There?
You can choose from 20 different MERV ratings divided into five main categories. Learn more about these categories below to understand how they influence air quality and where you can use them.
Rating 1-4
Many homeowners choose a MERV rating within this range for its low price point. However, affordability comes with the trade-off of fewer particles filtered. It can remove the following:
- Sawdust
- Dust mites
- Fibers from fabrics
- Pollen
Rating 5-8
Residential houses and small commercial properties may use this category. It filters smaller particles than the first category while allowing others to escape. In addition to particles filtered by the first group, these ratings will remove:
- Mold spores
- Household dirt and dust
- Lint fibers
- Concrete dust
Rating 9-12
This rating category is an upgrade from the previous ones. Laboratories and medical settings may use them, as well as regular commercial and residential properties. They remove the following:
- Humidifier dust
- Legionella
- Coal particles
- Lead particles
Rating 13-16
“What MERV rating do I need?” you might wonder. In most cases, filters with ratings between 13 and 16 are as high as you can go. HVAC technicians only recommend them for residential and commercial properties housing people with severe respiratory sensitivities and other health issues. Generally, hospitals and surgical facilities use this category. The filters remove:
- Tobacco smoke particles
- Transportation fumes
- Aerosolized bodily fluids
- Pesticide dust
- Pet dander
Rating 17-20
Finally, this category doesn’t typically circulate in an average store’s retail. Industrial and medical facilities almost exclusively use this restrictive filter type. Filters rated 17 and above eliminate:
- Viruses and bacteria
- Carbon
- Smoke
- Microbial irritants
- Salt
- Radon
What MERV Rating Do I Need?
Most residential HVAC systems can adequately operate with MERV ratings between 1 and 16. With 16 options available, you might feel overwhelmed. Should you select an economic filter or a highly effective one?
Each rating comes with pros and cons. Lower ratings cost less and allow more air to circulate throughout your home. However, they also don’t remove some of the main allergens and irritants affecting your health and comfort.
On the other hand, higher ratings effectively remove these contaminants, making breathing less of a chore and eliminating irritants that cause inflammation and allergic reactions. But they often cost more and can restrict airflow or stress an HVAC system.
Before choosing a MERV rating, check your HVAC owner’s manual. The manufacturer may specify a recommended rating for your system. You can also request a second opinion from a trusted HVAC technician. They can test your indoor air quality and suggest an effective filter for your needs.
You can also use the guide below to make an informed purchase.
- MERV 13-16: You have pets, suspect a mold problem, or expose your home to pollutants like smoke or pesticides.
- MERV 9-12: You have concerns about outdated building materials affecting your health. You might also use supplemental HVAC appliances like fireplaces, dehumidifiers, and portable air purifiers.
- MERV 5-8: You have concerns about mold and basic household grime collecting throughout your home.
- MERV 1-4: You want to save money with the most basic level of protection.
What Happens If I Use the Wrong MERV Rating?
If you proactively pursue a healthier indoor environment, you might feel tempted to purchase the highest MERV rating. Alternatively, you might choose the cheapest rating in bulk to save money. But choosing too high or low a rating has consequences.
Installing a filter with too high of a rating overworks your HVAC system. As it creates more air resistance, the system struggles to pull sufficient air through. Issues like prematurely worn or broken parts may manifest as a result.
Choosing a low rating allows more particles to stay in your home. Additionally, those particles could accumulate within your HVAC components. This issue also increases resistance and prevents various parts from working efficiently.
Find the Perfect MERV With SM Mechanical Services
“What MERV rating do I need for my home?”
Let the SM Mechanical Services team find the answer! We know numerous ways to develop a more energy-efficient HVAC system. Call 860-544-2026 to schedule indoor air quality services today!