If you've recently replaced your HVAC filter and noticed it's not collecting dirt, the problem could be with the size or type of filter you're using. A filter that doesn't fit properly may allow air to bypass it altogether, meaning dust and debris won't be trapped.
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.
If you're unsure about whether the air filter is clogged, hold it up to a light source. 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.
Soot Accumulation
If your air filter is coated with a black substance, soot might be the culprit. While the presence of soot on your filter might seem alarming, it's a testament to the filter's efficiency. After all, it's better for the soot to be trapped in the filter than in your respiratory system.
We like to recommend replacing your filter once every 3 months. However, if you're seeing a filter completely covered in dust, hair, dander, and dirt at the 3-month mark – you may need to take additional steps to make sure your filter isn't getting too clogged too quickly.
In some cases, a filter that's not getting dirty could simply mean that your home is unusually clean or free from airborne particles. If your home has hardwood floors instead of carpets, minimal dust-producing activities, or advanced air purification systems, there may be fewer particles for the filter to capture.
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.
For most homeowners, black air filters aren't a cause for panic. They simply mean that you need to increase the frequency that you change your air filters, and that the filter is doing its job.
If there is a lot of dust, pet dander, or other particles inside your home, your air filter can get dirty very quickly.
How Often Should You Clean Your Air Conditioner's Filter? It is recommended that you check your air conditioner's filter every 15 days, cleaning it at least once a month during the peak months of usage.
A clean air filter is usually white or tan. Over time when dirt and grime accumulate on it, it turns dark brown or black. Always check your filter in a well-lit area. If your filter is dirtier than usual, it's time to replace it.
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 brand-new air filter, or at least one in good condition, should be relatively clean. Fresh filters feature a white or off-white color, while older filters may be darker in color due to all the dirt and debris they've collected. If your filter looks dark or off-color, bring in a mechanic to check it out just in case.
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.
The most common problem you will face with a backwards facing filter is simple inefficiency. If your furnace is forced to blow air through the non-porous end of a filter, it will take more energy to do so. The blower will be overworked and you will pay more money for your heating.
As the system is working harder to get around clogged air filters, it can cause the entire system to overwork and eventually break. If this happens, you'll need to replace the entire system, which can cost anywhere from $4,000 to $12,000.
If the filter isn't picking up any dust, then it could mean a problem with your air conditioner. The air conditioner might not be strong enough to pick up the dust or be damaged. Check on the air conditioner to make sure that it isn't dirty or damaged, and run it for a bit before checking again.
If you notice a lot of dust in your house, it's likely due to a combination of factors affecting air quality and ventilation. Dust particles from outside can enter through open windows or doors, while indoor sources like pet dander, dead skin cells, and fibers from textiles contribute to the buildup.
Black Soot Deposition
Black soot can quickly turn our air filters black. This is usually a result of burning candles. Candles are made of carbon-based materials that don't all combust when burned. They end up producing tiny soot particles which then get into our carpet, on our furniture, and in our air filters.
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.
You can usually tell that the blackness in your air filter is mold because it'll be wet and slimy, rather than dry and powdery like soot. By the way, try not to touch the mold too much. It's not good for you.
Simply put, a black mist filter (sometimes known as a black diffusion filter, pro mist, or Cinebloom filter) is a filter placed in front of a camera lens that will give images (or video) a soft, diffused, ethereal look—commonly associated with the “cinematic” or analogue visual styles of photography and videography.
A new, clean new air filter keeps your HVAC unit running smoother and running longer, extending its useful life.
The simple answer is: not for long. Ideally, your AC should never operate without a filter for more than 6-8 hours. Going beyond this can negatively affect both your system's health and your home's air quality.