If you have a heating and/or cooling system in your home, then you have one or more supply vents. The supply vents are where the air handler draws air back in to the system in order to be cooled or heated. All HVAC systems require an air filter to be placed in the supply vent in order to prevent large particulate matter. Air filters trap particles and become saturated over time. A dirty air filter no longer performs well and thus needs to be replaced. If you continue using a dirty filter, static pressure rises and the filter becomes compromised, and this leads to a wide range of problems.
Dust Accumulation in the HVAC System
The primary reason HVAC air filters are used is to trap the large particulate matter that would otherwise flow into the system. Due to pressure within an HVAC system, dust and other particles do not necessarily flow back out through the return vents. Instead, much of that particulate matter settles on the HVAC equipment and in the ductwork. This dust accumulation is bad for the equipment because it leads to increased wear and tear, especially as it mixes with lubricants and other substances and becomes gunk. The reason HVAC companies clean this equipment during seasonal maintenance is to avoid the wear and tear that the accumulation of dirt and grime will lead to over time.
Increased Static Pressure
While an air filter can become compromised over time and lead to more dust accumulation, that isn’t the main concern with a dirty filter. What generally happens with a saturated air filter is that it restricts airflow, and restricted airflow leads to elevated static pressure within an HVAC system. Static pressure is very important as each system is designed to operate within certain pressure parameters. If the pressure is too high, your equipment will not operate as efficiently. The first signs will often be weak airflow and hot or cold spots throughout your home. But the problems here extend beyond comfort. The HVAC equipment will be working much harder and less efficiently.
Increased Energy Costs
Less efficient operation translates into a higher consumption of electricity or fuel. How much depends on a wide range of factors, but the difference is usually significant. In fact, the Department of Energy estimates that using an HVAC filter beyond its useful lifespan increases energy costs by 15% of the average American home.
Increased Maintenance Costs and Total Cost of Ownership
The costs associated with operating an inefficient HVAC system are not limited to the short term. If you have your system serviced on an annual basis, it may drive up your maintenance costs. Your HVAC company may have to recommend preventative repairs sooner, and without regular maintenance, an inefficient system will be more prone to sudden failures that require repair. Such wear and tear have an accumulative effect as well. It decreases the expected lifespan of your system. That means that your total cost of ownership is higher and your return on investment is lower.
Dirty Ductwork
Much of the particulate matter that makes its way into your HVAC system will settle in your ductwork. The EPA recommends that you clean ducts as needed, and if dust is accumulating in your ducts faster, then you are going to need to schedule that service more frequently. The National Air Duct Cleaners Association recommends every three to five years for the average home, but poor HVAC filter and maintenance habits could lead to you having them cleaned every other year or so.
Diminished Indoor Air Quality
Be mindful that HVAC filters are not used for the purposes of indoor air quality. You never want to purchase an HVAC air filter with air quality in mind—more on that in a moment—but it is a secondary effect. Dust in your HVAC equipment and ductwork is difficult to access to clean. Dust kept out of the system can be filtered, dusted, vacuumed and so forth. One of the biggest issues with dust in ductwork is that it acts like a sponge that absorbs pollutants and contaminants in the air and remits them over time, which can make it very difficult to maintain optimal indoor air quality.
Unpleasant Smells
Dust also traps gases, which include volatile organic compounds but also bad smells. Over time, those smells can become pervasive in ductwork, and when that happens, it may be all but impossible to make the home smell fresh when the HVAC system is running. In such a scenario, you’ll need to schedule a duct cleaning appointment as soon as possible.
How Often Should You Change Your Air Filter?
The general advice is to change your HVAC filters every three months, but this is a guideline for the average home. If you have a large household or multiple pets, you may need to change them more often. If your household consists of only two people without children or pets, you may need to change them less frequently. Rather than follow a set rule, it’s better to inspect your filters once a month and swap them as soon as you can see dirt. When you can see it, that means that the filter is becoming saturated.
Selecting the Right Filter for Your HVAC System
Every system is designed for a specific MERV rating. Determine what that is for your particular equipment and purchase a filter with that rating. Never purchase a HEPA filter or the like as it will dramatically increase static pressure in the system. Most homeowners use disposable filters. If you don’t mind the additional chore of cleaning the filters, you can save money over time with reusables.
Other Air Filters in Your Home
You may have other air filters in your home, such as those used by portable air purifiers or whole-home air purification systems. Note that those are different in that their sole purpose is to clean the air as effectively and efficiently as possible. There are no static pressure concerns. Therefore, you want to purchase the best air filter your unit supports, such as a medical-grade HEPA filter. You do still want to change them regularly as performance will decrease over time. That said, air filters designed solely for air cleaning generally have longer lifespans, and these systems will often have a prefilter as well. Therefore, you should change these based on the manufacturer recommendations.
Heating and Cooling in Bountiful, UT
Blue Best Plumbing, Heating, Air, Generators is the only women-owned and-operated HVAC company in Utah. We have more than 20 years of experience and take great pride in serving homeowners throughout Bountiful and the surrounding areas. Our team can replace your air filters for you and provide the professional advice you need to keep your HVAC system clean and running well. We install, replace, inspect, service and repair all manner of residential heating and cooling technologies. Our company also specializes in indoor air quality and offers HVAC maintenance plans. Call Blue Best Plumbing, Heating, Air, Generators today or contact us online to book an appointment or consultation or with any questions about our products and services.
