A dirty air filter is gross – often coated in gray or tan filth that may flake or fall off when disturbed. If it looks like this, it's time to replace your filter.
When you leave an AC unit's air filter clogged for too long, you can experience a failure of the entire system. This is because the unit can only work for so long at twice the power before it finally breaks down.
How Often Do I Need to Change Out My Air Filter? Generally, most air filter manufacturers and HVAC companies recommend changing your air filter every 90 days, or 3 months. That can change based on where your home is located (ex. dusty, dry climates), if you have any pets, and the age of your system and equipment.
If you don't change your air filter, it can quickly become clogged with dust and debris, preventing proper air filtration. This leads to a variety of issues for your HVAC system including system inefficiency, higher energy bills, inadequate air quality, and ultimately failure.
A clean air filter is off-white in color and will have no dirt or debris caught in its folds. A dirty air filter, on the other hand, will appear gray or brown in color and you'll likely be able to see dirt trapped between the layers of fabric. This dirt is getting in the way of the flow of oxygen to the engine.
Reusable filters can be washed and replaced. However, the disposable filters you use in your HVAC system aren't made to shed water after they get wet. The moisture the filter retains can encourage mold growth over time, and your HVAC system might spread the mold spores throughout the rest of your home.
Poor Air Quality
If the filter is too dirty to do its job, those unwanted particles can collect in your ductwork and cling to the internal components of your HVAC system, ultimately diminishing air quality throughout your house.
If your AC isn't cooling your space as effectively as it once did, or if the airflow seems weaker, a dirty filter could be the culprit. Cleaning it could bring back your AC's cooling power.
First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.
No, you should never run your AC without a filter!
While your HVAC unit will run, it should never run without an air filter. Dirt is the number one cause of air conditioners breaking down, so running your unit without an installed air filters can cause serious damage.
Filters with a MERV rating of 1 to 7 typically cost between $5 and $20. Filters with ratings of 8 to 13 can cost anywhere from $20 to $150. HVAC systems in residential homes usually don't need (and often cannot handle) filters with a MERV rating of more than 13.
You can usually tell a dirty HVAC filter needs to be changed just by looking at it. The filter will be gray or black and bits of debris will be visible. But you may notice other changes that indicate the furnace is not operating properly.
Visible dust around your vents can indicate that your air filter is breaking down and releasing particulate materials into your HVAC system. This can be confirmed by pulling out your filter and taking a look at it. If it is coated with dust or is beginning to disintegrate, it's time to replace this important component.
As previously discussed above, failing to change your filter means debris and dirt will soon clog your unit, causing it to overwork. This in turn raises your energy bills. It takes longer to cool your home. With an old air filter running, you'll notice that it takes so much time for your AC to cool you home.
Spray the filter with Simple Green All-Purpose Cleaner and let it soak. Rinse. Using a faucet or garden hose, rinse the filter from both sides, starting from the interior towards the exterior to prevent pushing dirt further into the fibers of the filter. Avoid wringing or stretching the filter – they can tear easily.
Wash the Filter
In a deep sink or outdoors using a garden hose, rinse the filter gently and thoroughly, and allow it to dry. If you need to provide a deep clean, soak the filter in a flat bin with 1 part white vinegar and 1 part warm water for an hour, and then rinse it gently with the hose.
If the filter is still in good condition, light should shine through. If the filter is dirty or clogged with debris, the light will be obstructed, indicating it's time for a replacement. The presence of visible mold is another one of the dirty HVAC filter symptoms that indicates it's time for a replacement.
A dirty air filter can cause your vehicle to throw a Check Engine code. During this instance, the Check Engine Light of your vehicle will turn on. The light turns on because your vehicle is sensing that its engine isn't receiving enough air.
With that said, how dirty should an air filter look? A dirty engine air filter will be either completely dark brown or black. If this is the case, it's time to install a replacement.
What happens if your HVAC filter is dirty? A dirty HVAC filter restricts airflow, which can lead to poor system efficiency, increased energy costs, and wear and tear on the unit.