Many different factors are involved in keeping your home properly heated and cooled. The condition and efficiency of your furnace and air conditioner play a major role in your overall indoor comfort and also your heating and cooling costs. Regular maintenance is vital for ensuring that your HVAC system is free from any issues and functioning as efficiently as it should.
Nonetheless, one other factor that many people tend to neglect is their furnace filter. Not using the right air filter or not replacing it frequently enough can lead to a wide range of issues. Increased energy costs, insufficient heating and cooling, and damage to your HVAC equipment are just a few of the potential consequences. With this in mind, here is everything you need to know about air filters and which ones are best.
What Does a Furnace Filter Do?
The air filter plays an important role in preventing dust and other airborne particles from damaging your HVAC equipment. Although it is often referred to as a furnace filter because of its location next to the furnace, the filter protects your air handler and the rest of your HVAC system as well. If the filter is damaged or missing, it can allow particles to get inside the equipment and quickly damage any moving parts such as the fan motor.
Damage can also result if you don’t replace the filter regularly. When the filter gets overly dirty or clogged, it drastically reduces the airflow. This means that the air handler and blower need to work much harder to draw air in, which can result in increased wear and tear and a more frequent need for repairs. The same issue also makes it much more difficult for the system to properly circulate air throughout the home, which can lead to uneven or inadequate heating and cooling.
Although the primary purpose of the furnace filter is to protect your HVAC system, it can also play a role in your home’s indoor air quality. The most basic filters are generally only effective at capturing large particles like dirt, dust, and hair. However, there are more efficient filters that can also trap pollen, mold spores, combustion particles, gas fumes, and other airborne allergens and contaminants. While not as effective as a whole-home air filtration system, these more efficient filters can still contribute to improved indoor air quality.
Types of Furnace Filters
Furnace filters come in a huge variety of styles and sizes, and it is important to use the correct filter for your specific system. Most residential furnace filters are 1 inch thick, but they can also be as thick as 3 inches. Figuring out what size of filter you need is as simple as looking at your existing filter or measuring the opening where it goes.
Determining what type of filter you need can be a lot more difficult. You can find filters made from aluminum, cotton, and synthetic materials. They can be pleated or flat, disposable or washable, electrostatically charged, and more. All of these factors play a role in determining how efficient the filter is and also its price. The fact that there are so many different types of filters can make it difficult to compare them and determine which is best. For this reason, the main thing you should always focus on is the filter’s rating.
Understanding Furnace Filter Ratings
All furnace filters are tested to determine how efficiently they can trap airborne particles of varying sizes and then given a rating based on this information. Most commonly, furnace filters are rated based on their minimum efficiency reporting value, or MERV. The least efficient filters are given a rating of MERV 1 while the highest efficiency filters are rated MERV 20. Nonetheless, for practical purposes, the scale essentially stops at MERV 16 as anything above this is considered a true HEPA filter and is only used in cleanrooms where sensitive electronics are manufactured.
MERV 1 filters are primarily used in applications like window AC units while MERV 16 filters are used in hospitals and some commercial and industrial applications. For residential HVAC systems, most filters will range between MERV 4 and MERV 12. Anything below a MERV 4 is simply not efficient enough to protect your HVAC equipment. On the other end of the scale, anything above a MERV 12 is often too restrictive for residential HVAC systems in terms of airflow. Most residential systems are simply not powerful enough to handle this level of filtration, and using too efficient a filter can result in insufficient cooling and heating or potentially damage your equipment.
If your primary concern is protecting your HVAC equipment, a MERV 4 or MERV 6 filter should be sufficient. However, if you are also concerned about indoor air quality, you may want to upgrade to a MERV 10 or MERV 12 filter. Although these more efficient filters do cost more, they can be well worth the price if you suffer from allergies, asthma, or other respiratory ailments.
You may also encounter two other rating scales. 3M uses the MPR (micro-particle performance rating) scale while The Home Depot uses FPR (filter performance rating). Both of these rating systems work in the same way as MERV with the most efficient filters having the highest numbers. There is no reason to get into much detail about what the specific numbers mean as most of these filters will also show what they are equivalent to on the MERV scale. You can also find numerous charts online that allow you to compare the different rating scales.
Are Washable or Disposable Filters Better?
Generally speaking, there isn’t much of a difference between washable and disposable filters in terms of efficiency. As long as both have the same rating, they will provide the same level of filtration. The only real differences are in terms of price and convenience. Washable filters have a higher up-front cost, but they will save you money over the long run compared to buying disposable filters. These filters can be a good option if you’re willing to spend the time to clean them regularly. Still, most homeowners choose disposable filters for convenience.
The Importance of Replacing Your Filter Regularly
You should always replace or wash your filter at least once every 30 to 90 days. Waiting any longer than this risks the filter getting clogged and affecting your indoor comfort or damaging your HVAC system. You can usually get away with replacing the filter every two to three months when your heating or air conditioning isn’t used all that often. However, you should definitely check the filter at least every three to four weeks during the middle of summer and winter when your HVAC system runs much more frequently.
It is also important to make sure that you put the new filter in the right way. Air filters can only work one way. This means that it won’t serve its purpose if you don’t install it correctly. All filters have an arrow that shows which way they need to go, and this arrow should point towards your furnace or air handler.
Professional HVAC Services and Solutions
If you have any questions about air filters or anything else related to your home’s HVAC system, the experts at Gallagher's Plumbing, Heating and Air Conditioning are happy to help. We have three locations in California, in Sacramento, Olivehurst, and Los Molinos, and we serve customers throughout the North Valley and Greater Sacramento area. Our HVAC technicians specialize in furnace and air conditioner installations, maintenance, and repairs. We also have a team of professional plumbers that work on water heaters and water purification systems. Contact Gallagher's Plumbing, Heating and Air Conditioning today to schedule an appointment or if you have any questions.