Perhaps one of the most important, yet overlooked parts of home maintenance, is the air filter for your heating, ventilation, and air conditioning (HVAC) system. Whether you know it or not, up to half of your energy bill may be due to heating and cooling costs1. To help keep the utility bill low, and help to maintain a level of comfort, it’s important to ensure the high efficiency operation of your HVAC system. The air filter helps your HVAC system perform to its maximum potential at the lowest operational cost. In this article, we’ll discuss the benefits of an HVAC air filter, describe the different rating types, and some factors to consider before buying an HVAC air filter.
HVAC Air Filters: Buyer’s Guide
HVAC Air Filter Benefits
The air filter is a major component of the HVAC system. Keeping an eye on its condition is vital to achieving the following benefits:
- HVAC Optimization: One of the primary benefits of an air filter is a clean HVAC system that works efficiently. Specifically, the HVAC air filter traps and holds many contaminants to prevent them from passing through your heating and cooling system and into the air you’re breathing indoors. These include, but are not limited to, dust, dirt, pollen, animal fur, hair, and microorganisms. If you don’t replace your air filter regularly, your HVAC system could experience failure due to having to work harder to maintain a certain temperature, which could lead to maintenance being needed, which might prove to be an expensive oversight!
- Energy Cost Savings: If your HVAC system is operating with a dirty air filter, that airflow may become restricted causing the whole system to strain itself by utilizing more energy as it tries to maintain the set temperature. A clean HVAC air filter lets the air flow unobstructed, helping to prevent wasted energy.
- HVAC Longevity: Heating systems may be running on either gas, oil, or a hybrid of both fuel types. Two key processes of air conditioning are: 1) the furnace, where combustion gases are generated; and 2) the heat exchanger, where the air from your home is warmed up by these gases. A clean air filter can go a long way in extending the operating life of your HVAC system by protecting the furnace’s fuel and heat exchange system.
- High Air Quality: A good HVAC air filter should be able to drastically reduce airborne dust, allergens, bacteria, and viruses. Besides this, larger particles like lint and pollen are also kept out of the air circulating in your home. Replacing your HVAC air filter at the recommended timeframes can help to significantly improve the air quality within your home. Those individuals who are sensitive to airborne particles would especially benefit from a good HVAC air filter.
HVAC Air Filter Efficiency Ratings
Since there are different types of HVAC air filters from different brands, consumers want a quick way to determine the efficiency of each model. The easiest way to achieve this is by assigning a number relative to the performance of each HVAC air filter. For this purpose, different organizations have developed rating systems so that consumers may compare HVAC air filters of the same performance class. Here are the most commonly used HVAC air filter rating systems2:
- MERV: It is a Minimum Efficiency Reporting Value (MERV) developed by ASHRAE® (The American Society of Heating, Refrigerating, and Air-Conditioning Engineers). The typical range of MERV ratings for HVAC air filters is 6 to 13. The higher the MERV rating of your HVAC air filter, the better it is at filtering finer particles.
- Example Product: Aerostar® MERV 13 Pleated Air Filter
- MPR: Another popular measure of an HVAC air filter’s performance is the Microparticle Performance Rating (MPR) developed by 3M®. MPR measures the ability of an HVAC air filter to capture particles smaller than a micrometer, or micron (a millionth of a meter: 1/1,000,000 meters). A human hair is typically 75 microns across, so you can imagine how effective HVAC air filters scoring well on MPR are. It is recommended you get an HVAC air filter somewhere between 1500 MPR and 1900 MPR.
- Example Product: Filtrete™ AC Furnace Air Filter MPR 1500
- FPR: Massive home improvement retailer The Home Depot® has also developed its HVAC air filter rating system called Filter Performance Rating (FPR). They’ve kept it simple. The scale is from 1-10, and the higher the number, the better the HVAC air filter rating.
- Example Product: Honeywell® Allergen Plus Pleated FPR 7 Air Filterr
- HEPA: Some HVAC air filters are certified as High-Efficiency Particulate Air (HEPA) cleaners. These are electrostatic filters fitted inside a furnace to capture dust and keep it from circulating in the air indoors. It can help people with lung diseases or asthma, but there is a downside; some HVAC systems may not be able to handle the relatively thick HEPA filters, and you might need a separate air purifier unit. HEPA certified air filters have a MERV rating that goes up to 20.
- Example Product: Germ Guardian® FLT4825 HEPA Air Purifier Filter
Factors to Consider Before Buying an HVAC Air Filter
All homeowners need to replace HVAC air filters from time to time. Before your next HVAC air filter purchase, you should consider the following factors to ensure you get the right make and model:
- Replacement Frequency: The HVAC service technicians recommend replacing an HVAC air filter is every three months. Beyond this time, your heating and cooling efficiency could be affected. However, you should check the HVAC air filter every month as environmental factors can shorten the life of an HVAC air filter. If it appears to be dusty and has changed color significantly from when it was new, it’s best to replace it.
- The Right Size: The physical size of the HVAC air filter is another important factor to be aware of. Your HVAC system may have a sticker or tag specifying the correct HVAC air filter size. If you can’t find that, try to look up your HVAC system online and find the correct HVAC air filter size from there. Another way to find the correct size is to remove the existing HVAC air filter and look for a label on its frame. You’ll want to note down the length, width, and depth before ordering a replacement HVAC air filter. If you put in the wrong sized air filter, it can potentially wreak havoc with your HVAC system hardware and reduce the effectiveness of the HVAC system as well.
- Professional Maintenance: Machines require regular maintenance, even if nothing appears to be wrong. It’s best to hire a licensed HVAC technician to change the HVAC air filter, make sure all electrical connections are meeting safety standards, calibrate the HVAC unit, and generally make it ready for the upcoming season. It’s recommended to get professional servicing done at least once a year.
Conclusion
HVAC air filters are essential for heating and cooling systems. Replacing the HVAC air filter regularly can help to improve indoor air quality by reducing dust and allergens, could save you money with lower monthly utility bills, and potentially extend the life of your HVAC system. You can judge the quality of a particular HVAC air filter through one of the quality ratings assigned to it. Make sure you’re getting the right sized HVAC air filter to ensure system efficiency and consider having a professional HVAC technician service your HVAC system at least once a year.
We hope you found this buyer’s guide helpful in making decisions for HVAC air filters. Please check out the following links to other articles within our Learning Library to learn more. .
