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.
If it looks dirty, dusty, or has clumps of hair and dust, it's time to change it.
The best way to know if the air filter needs replacement is via visual inspection. Locate the air filter housing (typically a rectangular box near the engine), open it, and look at it. The filter material should be almost white. If it's dirty, clogged, or covered in debris, it's time to replace it.
The best rule I've found is a visual check: if you can still easily see the individual fibers in the filter material through the dirtiest parts, it's still fine. If the accumulation starts to obscure them, time to change.
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.
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.
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.
When your car is idling or stationary, you should feel and hear the smooth vibrations of an efficient engine. If you notice unusual noises, in particular a coughing, popping or spitting noise, it suggests that the engine isn't getting enough airflow, which means your air filter needs to be replaced.
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.
Replacing your car's air filter can cost anywhere from $20-$50, depending on the type of vehicle you have and the quality of filter. A high-quality filter will ensure better airflow, engine performance, and fuel economy — so it's worth investing in a reliable one!
You can identify a dirty cabin air filter simply by looking at it. The location of the filter varies, but you can typically find it under your car's hood, near the cowl, or under your dashboard. If it has dust and debris on the surface or turned a darker color, then it might be time for a replacement.
Replacing a clogged air filter can increase fuel efficiency and improve acceleration, depending on your car make and model. When you realise that, it makes sense to regularly replace your air filters.
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.
If you don't change your AC filter, it will begin to fail. It will no longer be able to filter the air properly, letting dust and contaminants get into the HVAC system. Dust jams the moving parts of an AC such as fan motors and valves. Airflow is restricted which creates a strain on the system.
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. Below are five common dirty air filter symptoms and what causes them.
While an air conditioner should normally cycle on when it senses an increase in temperature, and off when it has sufficiently cooled the room off, short cycles can occur when you have a dirty air filter.
A Dirty or Discolored Filter
A clean and fresh filter will be mostly white in color but will get darker as it gathers dust and dirt. If your filter looks very dark and dirty, it might be time to change it. If you're unsure about anything, you can get a technician to check your filters for you.
Air filters that are overdue for a change are a common cause of HVAC system failure. Over time, dirt builds up in the heating and AC filters, causing components such as the motor to go into overdrive, which may eventually overheat your unit.
What if it's more than just a few slip-ups? In some rare cases, losing your “filter” can be a sign of something more serious, such as damage to the frontal lobes due to a brain injury or stroke, or a neurodegenerative condition such as frontotemporal dementia.