
While your HVAC filters are a small part of this much larger, more complex system, they play a major role in their efficiency. Without clean filters, you may find that your system doesn’t perform as well as it has in the past. On average, these filters should be replaced at least once every three months. However, you may find that the filters get dirty quickly and must be replaced more frequently.
But what could lead to your filters getting dirty so quickly? In this blog, we’ll discuss some of the most common reasons why your filters are getting dirty frequently and how to protect them and your system.
1. You Have Pets in Your Home
One of the main reasons why your HVAC filters may be getting dirty so quickly is because you have pets in your home. No matter how frequently you brush and bathe your pets, their dander is still bound to get into the air in your home. As it floats through your home, it may get pulled into your system, clogging your filter and dirtying it faster than you expect.
2. There is Mold in Your Home
If you are experiencing moisture problems in your home, like leaks in your HVAC systems, this may be why your HVAC filters get dirty so quickly. It isn’t uncommon for mold spores to grow on your air conditioning unit’s filter. Once mold spores make their way onto a surface, it only takes about 24 hours for them to spread, quickly clogging your filter and dropping system efficiency.

3. Allergens are Bad in Your Area
As allergy season approaches, you may find that your HVAC filters begin to clog more quickly than they have in the past. Allergens make their way into your home whenever the system runs, you open windows, or you come in after a day out. If you want to protect your home from this filter clogging, you may want to consider investing in a whole home air filtration system to capture these allergens before they cause more problems.
4. You Used Cheap HVAC Filters
When you’re looking at the HVAC filters at the store, you might think they are all exactly the same. However, every filter is ranked based on the Minimum Efficiency Reporting Value (MERV) rating. The higher the quality of a filter, the better the MERV rating. Cheaper filters often have low MERV ratings and will only have about a 30-day lifespan before you will need to replace them.
5. You’re Using the Wrong Thermostat Setting
If you walk past your thermostat and notice that the fan is set to ‘on,’ this might be why your HVAC filters are getting dirty so quickly. If the fan is turned on all day, it will run, even when your heater or air conditioning unit isn’t on. This means air is always passing through the filter, leading to an increased chance that your filter will clog faster than you expect.

6. You Smoke in Your Home
If you smoke in your home, this can take a major toll on the health of your HVAC filter. Smoke particles attach to dust particles, getting trapped in your filters more frequently. If you choose to smoke in your home, you may need to replace your filters every few weeks to keep them fresh. If you want to avoid the excessive cost of frequent replacements, you may want to consider smoking outside instead.
7. There is Excessive Soot
Are you a frequent candle lighter or a lover of your wood-burning fireplace? If you find yourself lighting these frequently, you may also notice your HVAC filters blogging quickly. The soot that results from lighting flames in your home may get sucked into your filters. However, to avoid dealing with this soot accumulation, consider scheduling chimney cleanings, replacing your wood-burning system with a gas fireplace, and trimming your candle wick before lighting.
How to Care for Your HVAC Filters
There are a few things you can do to ensure your HVAC filters last as long as possible. Some of the easiest things you can do to protect your filters include:
- Change them frequently, about once every 90 days
- Use pet-specific filters designed to handle pet dander
- Schedule regular HVAC system maintenance
- Cover vents when performing home renovations or remodeling
- Use filters with the right MERV rating for your needs

Schedule HVAC Maintenance with R&D Heating & Air
If you want to protect your HVAC system from premature breakdown, turn to our team at R&D Heating & Air for annual maintenance. For years, our team has provided the most reliable maintenance services to homeowners across Roy, Utah. With our experience and preventative maintenance services, you can trust that any minor problems, including dirty HVAC filters, are addressed before they lead to more costly system damage.
When you are ready to schedule annual maintenance for your HVAC systems, don’t hesitate to contact R&D Heating & Air for support.