Did you know your air filter can impact how much energy your household uses each month? That inexpensive air filter is directly tied to the HVAC system and could help you save hundreds of dollars a year – if you choose the right one.
Air filters impact the HVAC system in two key ways:
They keep contaminants out of the HVAC equipment.
They can potentially restrict airflow.
When the airflow is restricted the HVAC system has to work harder to regulate the temperature inside a home. When the HVAC system works harder it increases the amount of energy that’s used to heat and cool the home.
The goal with an air filter is to find a good balance between removing contaminants from the air without impeding the HVAC system.
Pay Attention to the MERV Rating
If you’ve looked at the air filter aisle of a big box home improvement store you may have noticed something called the MERV rating. MERV stands for minimum efficiency reporting values. It’s a measure of the air filter’s capabilities.
A household air filter is given a MERV rating to indicate how well it clears the air of particles between the size of 0.3 and 10 microns and what kind of particles are removed. The higher the MERV rating is the better it is at removing particles.
The one downside is air filters with a higher efficiency rating are thicker, more pleated and more particles are captured, all of which can restrict airflow.
The MERV rating scale ranges from 1 to 16. A MERV rating between 11-13 is usually a good mix of air purification and airflow.
Why You Don’t Want a HEPA HVAC Air Filter
You may have heard of HEPA air filters. HEPA stands for high efficiency particulate air. They are the air filters that are well above a MERV 13 rating. A HEPA air filter can clear 99.97% of particles that are 0.3 micron. Particles at this size are the worst because they penetrate the easiest.
HEPA air filters are amazingly good at clearing the air, which is perfect for an air purifier or vacuum bag. But they would put a horrendous strain on an HVAC system due to airflow restriction.
Household Considerations for Air Filter Selection
Now that you understand the impact of MERV rating, it’s time to consider your household members, activities and routines. There are specialty air filters that may be better suited for your home than a standard option.
If someone has allergies: Look for an air filter that has a higher MERV 13 rating and specifies that it removes allergens. Also, consider using a HEPA air purifier in the person’s bedroom.
If someone has asthma or a respiratory illness: Look for an air filter with a higher MERV 13 rating and can remove virus particles from the air.
If you have an indoor pet: Look for an air filter that removes animal dander. Reusable filters that need to be cleaned aren’t recommended.
If you have pet or smoke odor: Look for an air filter with an activated carbon treatment to remove odor particles from the air.
If you have an existing HVAC system: It’s best to always stick to the air filter type that’s recommended by the manufacturer. Either look at the current air filter or read the HVAC system manual.
No Matter What, Change or Clean Air Filters Regularly
No matter what type of air filter you ultimately end up going with, it will need to be cleaned or replaced regularly. How often this needs to be done isn’t the same for all households.
- Generally speaking, a disposable air filter needs to be changed at least every three months.
- If you have pets in the home it’s best to change the air filter every 1-2 months.
- If anyone in the home has allergies, asthma or another respiratory problem change the air filter every 1-2 months.
- In the summer months when the HVAC system is used more often consider changing your air filter at least once every two months.
- Reusable air filters should be washed at least once a month.
Keep in mind an air filter that needs to be changed or cleaned is possibly restricting airflow and causing the HVAC system to work overtime. The extra energy use could even cost more than replacing the filter. The Department of Energy estimates that replacing or cleaning dirty air filters can reduce HVAC energy use by as much as 15%.
Air filters are simple yet essential parts of an HVAC system that can help reduce or cause an increase in your utility bill. Get a better idea of what your HVAC expenses will be in New England by comparing current electricity rates.