Breathe Easy: How to Determine the Correct Size of Air Filter for Your House

Welcome to our latest blog post, "Breathe Easy: How to Determine the Correct Size of Air Filter for Your House." Few things are more important than the air we breathe, especially inside our own homes. That’s why it’s crucial to have the correct size of air filter in place to ensure healthy air quality and prolong the lifespan of your HVAC unit.

Do you know how to determine the correct size of air filter for your house? If not, no need to worry. In this article, we’ll provide you with everything you need to know about finding the right size air filter for your home. From the reasons why it’s important, to the steps you need to take to ensure you get the right fit, we’ve got you covered.

So, sit back, relax, and let us guide you through the process of determining the correct size of air filter for your house. Take these steps and breathe a little easier knowing that you’re taking action to keep your home healthy and your HVAC system happy!

1. Why is it important to have the correct size air filter?

Having the correct size air filter is essential for maintaining good indoor air quality. A filter that is too small will not be able to capture all the pollutants and particles in the air, which could lead to poor air quality and potential health risks.

Conversely, a filter that is too big could leave gaps that allow air to bypass the filter, reducing its efficiency and increasing energy costs. It's essential to choose the right size air filter for your specific HVAC system to ensure optimal functioning.

Moreover, if you choose an undersized filter, it will quickly clog with the airborne debris, restricting the airflow and making your heating, ventilation, and air conditioning (HVAC) system work harder to circulate air. This extra effort will damage your HVAC system and lead to costly repairs and maintenance.

Last but not least, a correctly sized filter can prolong the life of your HVAC system by trapping air particles and debris that could cause blockages in your system. When your system has to work harder and longer than it should, it will wear out faster and need to be repaired or replaced sooner.

It's critical to follow the manufacturer's recommendations and guidelines when choosing the correct size filter for your home's HVAC system. Doing so will ensure that your air quality stays healthy while saving you money on energy costs and repairs.

2. How to Measure Your Current Air Filter

It's important to measure your current air filter before purchasing a replacement to ensure you get the right size. Here's how:

  1. Turn off your HVAC system to prevent any debris or dust from getting in your system while you work.
  2. Locate your current air filter. It's typically located near the main air intake vent.
  3. Remove the filter from the vent and lay it flat on a clean surface.
  4. Measure the length, width, and thickness of the filter using a ruler or tape measure. Make sure to measure all three dimensions, as filters can be different sizes in each direction.
  5. Write down the exact measurements of your current filter so you can purchase a replacement with the correct dimensions.

As a reminder, air filters should be replaced every one to three months, depending on usage. Keeping your air filter clean and well-maintained can improve indoor air quality and help your HVAC system work more efficiently.

Understanding MERV Ratings

MERV ratings are an essential factor in determining the effectiveness of air filters. The higher the MERV rating, the better the filter is at capturing smaller particles, including allergens and pollutants.

However, it is important to note that filters with higher MERV ratings may also restrict airflow and put additional strain on your HVAC system. Therefore, it is essential to find the right balance between the filter's effectiveness and your system's capacity.

For residential purposes, experts recommend MERV ratings between 7 and 13. These filters can capture most common airborne particles, from pollen to pet dander, without impacting your HVAC system's performance significantly.

When choosing an air filter, consider your home's unique needs and HVAC system. If you or someone in your home suffers from respiratory issues, allergies, or asthma, it may be wise to opt for a filter with a higher MERV rating.

Overall, understanding MERV ratings can help you make informed decisions when selecting an air filter for your home. Balancing the filter's effectiveness with your system's capacity can keep your air clean and safe without putting undue strain on your HVAC equipment.

Tips for Choosing the Right Air Filter Size and MERV Rating

When it comes to air filters, size and MERV rating are two critical factors to consider. Here are some tips to help you choose the right size and rating for your home:

1. Know your system: Before purchasing an air filter, it's essential to understand the type of HVAC system you have. High-efficiency systems may require filters with a lower MERV rating to prevent airflow restriction. On the other hand, standard systems can handle higher-rated filters.

2. Measure your current filter: To find the correct size of air filter, you need to measure your current filter's dimensions. This will ensure that the new filter fits correctly and prevents any gaps that can allow debris to enter the system.

3. Consult with a professional: If you're unsure about which MERV rating to choose, consult with a professional HVAC technician. They can recommend the best option based on your system's specifications, your home's needs, and your budget.

4. Consider your family's health needs: Air filters can help improve indoor air quality, which is particularly crucial for individuals with allergies or respiratory issues. If you have a family member with specific health needs, consider a filter with a higher MERV rating to capture more particles and contaminants.

By following these tips, you can ensure that you choose the right size and MERV rating for your air filter, improving your home's indoor air quality and the health of you and your family.

When to change your air filter

Air filters should be changed regularly to maintain optimal efficiency and indoor air quality. The frequency of filter changes will depend on several factors, such as the type of filter you have, the number of people in your home, and the presence of pets or allergies.

As a general rule, filters should be replaced every 1-3 months. However, you may need to change them more often if you have smokers or pets, or live in a particularly dusty or polluted area. You should also replace your filter if you notice poor air flow from your vents or if the filter appears dirty or clogged.

It's important to note that neglecting to change your air filter can lead to decreased indoor air quality, increased energy bills, and potentially costly repairs to your HVAC system.

To stay on top of filter changes, mark your calendar or set reminders on your phone to replace your filter every few months. It's a small task that can make a big difference in your home's air quality and overall HVAC system efficiency.

Conclusion

In conclusion, choosing the right air filter size is an important factor in maintaining the air quality in your home. With the right size in place, you can be sure that your HVAC system is working efficiently while providing clean and healthy air to breathe. Remember to check the size of your air filters regularly and replace them when necessary. In addition, don't forget to consider the MERV rating of the filter to ensure that it's effective in removing airborne particles and allergens from your home. By following these simple steps, you can enjoy a comfortable and healthy indoor environment for you and your loved ones.

Frequently Asked Question

The most recommended air filter for home use is the HEPA or the high-efficiency particulate air filter. It can remove up to 99.97% of air-borne pollutants and allergens at home. By that, it means it could remove pollutants such as dust, mold, pollen, pet dander, viruses, smoke particles, and bacteria. 

Whole house filtration is worth it if the household members suffer from allergies, asthma attacks, and other respiratory illnesses. Homeowners with a whole house filtration system report less frequent asthma and allergy attacks. 


Most standard-designed homes have 2 air filters right at their intake vents. The smaller the house, the fewer air filters you need. If it is larger, then you might need more to compensate per square foot of the house. 

By the rule of thumb, 3 months or 90 days is the most recommended frequency of changing the air filter. For those with pets or houses located in drier climates, then you might need to change it more frequently like from 6 weeks to 2 months interval.

Typically, it is just okay to use cheaper air filters as long as it does the job based on your needs. If you are not sensitive to dust, pollen, or pet dander, you might not need a very expensive air filter. Although cheaper air filters are not as effective as their expensive counterparts, they would still depend on your home setup. You might still have to replace them when they’ve reached their maximum life span.