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Serving Chester County & Surrounding Areas


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Signature HVAC Blog

My AC Filter Is Black! What Does This Mean?

air conditioning filterSpring is a season for spring cleaning, and that means you may be giving your HVAC system a little TLC. If you pull out the air filter and find that it’s black, you need to do a little digging. Here’s what a black air filter means, and what you can do about it.

Why Air Filters Turn Black

It can be surprising to pull out your air filter, only to find that it’s turned a strange shade of black, but this simply means that the filter has done its job. The filter is designed to trap particles, including dust, allergens, and pet dander, as they travel through your home’s air. As those particles build up, the color of the filter changes. Sometimes this happens more quickly when there is a lot of mold or moisture in the air or if the home has high amounts of allergens and particles in the air. It can also happen if the filter’s been in use for over a month.

What to Do About Black Air Filters

If your air filter is black, then you need to replace it. Once the air filter is full of particles and its color changes, then the HVAC system’s efficiency will be compromised. When the filter is full of gunk, air can’t flow through the system as it should. This makes the system work harder, increases your energy bills, and increases wear and tear on your home’s home comfort systems.

The challenge for homeowners is knowing when to change the filters. The fact is that each home is going to have a different time frame for filter replacement, but a good rule of thumb is to replace the filters every one to three months. If you’re noticing that the filter is black when you do change it, consider pushing up the changing timeline so you start changing it before it turns black. You may also want to consider air duct cleaning to get some of the debris out of your ductwork.

Black Air Filters & Mold

Most of the time black air filters mean you need to replace the filter, and nothing more. That said, if your filters are turning black very quickly, then you may have a mold problem. Mold puts your family’s health and safety at risk, and it needs to be addressed immediately by a qualified HVAC technician. Give the Signature team a call to discuss the likelihood that you have a mold problem right away. We offer a number of air purification and dehumidification services that can help protect your home’s air quality and your family’s safety.

West Chester Indoor Air Quality Solutions

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 you have questions or concerns about your air filters and your home’s indoor air quality, we’re here to help.

Call Signature at 610-738-8310 today to discuss air filtration and indoor air quality with our experienced and knowledgeable team.

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