If you've checked your air filter to find it black instead of the usual layer of grey dirt and dust, that's not normal. So, what's causing this? Soot build-up, also called “black soot deposition”, is most likely the reason behind a black filter.
Your air filter is black because of soot. This sounds scary, but, it's usually no big deal. The good news is that, if your filter is black with soot, it means it's doing its job. Better to have soot on your air filter than in your lungs, right?
It's most likely flakes of charcoal or activated carbon, a very popular filter material. It's not uncommon to see some charcoal on a new water filter. Flush the filter and see if more of it comes out. If the problem persists, you may want to contact the seller to return it.
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.
While dust and dirt are common culprits of a black air filter, there are a few scenarios that could lead to this result. Don't worry, it looks more scary than it is. In fact, it's actually a sign your air filter is doing its job. However, it's not necessarily something that should be happening regularly.
If your sediment filter is black, replace the cartridge. If the problem recurs, the issue is solid matter like iron particles.
Soot is one of the most common ways you can turn your air filter black. Most often, it is caused by candles or gas water heaters.
Black particles from the HVAC system are typically mold, rust or insulation.
More people walking into your home increases the amount of dirt and contaminants in your home. Furry pets also introduce hair, dirt, and pet dander. And the more contaminants floating around in your home, the faster your filter gets dirty.
Black dust can sometimes indicate mold presence, especially in damp and poorly ventilated areas conducive to mold growth. The indoor components of HVAC systems are particularly prone to mold due to their often damp, dark locations. Leaky ducts can introduce and encourage mold growth within your air handling system.
A black filter can be caused by candle smoke, soot from fireplaces or it can indicate that black mold is growing due to humidity and condensation in or around the furnace. Another cause of black filters is carbon monoxide which poses health risks and, in extreme cases, death.
Is Carbon Dust Safe to Drink? Although the black dust floating in your water might look unappealing, it's not considered harmful. In fact, some believe consuming activated carbon (charcoal) is beneficial for the following: Cleansing blood.
Mold can take the form of irregular black dust, clusters, or streaks, particularly noticeable on filters or where moisture accumulation is common. Regularly inspecting your window air conditioner, central air conditioning system, and or other AC units for these signs will help you catch mold infestations early on.
A brand new air filter is white or off-white in color, while a dirty air filter will appear darker with the dirt and debris visible.
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.
Wash your HEPA filter with warm water and allow it to dry if your model specifically states that water cleaning is safe. You can also soak your filter in hot water if it is extremely dirty. Clean non-washable, permanent HEPA filters using a vacuum to remove dust and debris.
Is no AC filter better than a dirty one? No. A dirty filter will slightly protect against some dust particles that will damage your AC system. Its better to have a dirty filter than having no filter.
Air cleaners are used inside offices and houses to maintain a comfortable indoor environment, but are often found to be contaminated with fungi. These air cleaners that disperse spores into the indoor environment with their strong air currents also cause fungal contamination and malodor.
Soot build-up, also called “black soot deposition”, is most likely the reason behind a black filter. Black soot deposition inside your home is more than likely caused by: Burning scented candles.
Soot particles released by wood fires or incomplete combustion of candle oils coalesce over time, forming black dust. It will continue to collect if surfaces aren't cleaned every day. The dust can accumulate on walls, windows, and cabinets as well as behind doors and in crevices if your home isn't well-ventilated.
Its smell is often described as musty and earthy, similar to the scent of dirt or wet, rotting leaves. If you see black spots or black dust appearing around air vents, there's a good chance that mold is growing inside.
Whether black or gray, any dark discoloration entails a dirty furnace filter and should be cleaned. On top of particle pollution, combustion can turn regular build-up into black soot and saturate the entire furnace filter. Pet dander, dirt, and dust don't cause black soot per se, but enough buildup can lead to it.
When the thermostat's fan setting is set to “ON” the indoor blower will run 24/7, constantly circulating air over the air filter. So now the filter is constantly catching airborne contaminants, causing it to quickly get dirty. Furthermore, your energy bills are higher because running a blower nonstop isn't cheap.
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.