7 Signs Your Air Ducts Need Cleaning

dirty dusty air ventilation air duct in toilet.

Have you noticed visible mold growth, excess dust, higher energy bills, and worsening allergies recently? Those are a few signs your air ducts need cleaning.

According to the EPA and the National Air Duct Cleaners Association (NADCA), the majority of homeowners should clean their air ducts only as needed. This means if you have pets, allergies, or other health issues, your air ducts may need to be cleaned more often. However, I recommend getting your air ducts inspected annually.

1. Visible Mold Growth

Mold is never something to play with, and if it’s forming in your duct system, that means a whole lot of mold spores are being spread throughout your home. 

Breathing in these contaminants, especially over a long period of time, can cause health problems because mold and mildew produce allergens, and, sometimes, naturally occurring poisonous substances called mycotoxins. Poor indoor air quality can result in sneezing, hay fever, itchy/watery eyes, runny nose, asthma attacks, and more. 

My Tip: Experts in mold removal are not the same as air duct cleaners. If there is visible mold, you need a mold remediation specialist.

2. Vermin Infestation

Think of air ducts as entryways to your house. Rats, mice, roaches, or snakes can sneak into your air ducts and potentially other areas of your home through cracks in unsealed ductwork or by chewing open their own access holes.

A face-to-face encounter with certain pests can be dangerous for you and your family, but your health can also be compromised by inhaling bacteria and viruses that may be present in the pests’ droppings, for example.

My Tip: I suggest looking out for gnaw marks, shed skin, eggs, droppings, animal sounds, and musty odor — all telltale signs of a pest problem.

3. Higher Energy Bills

It’s normal for homeowners to see small fluctuations in their energy bills — sometimes, energy costs go up slightly with each new season due to increased usage of air conditioning or heating.

But, if you notice an abrupt, drastic elevation in your utility bills, this could signal dirty air ducts. Dirty ducts, meaning there’s an excessive dust buildup, can potentially hinder airflow, energy efficiency, and overall function of your HVAC unit.

Learn more about HVAC maintenance with our guide: How to Maintain Your HVAC System.

4. Recent Construction

If, like me, you’ve ever walked through new home construction or lived through home renovations, you know that can bring on all types of debris — we’re talking particulate matter from drywall, wood, asphalt, and the like.

Soon after construction is complete, be sure to schedule a thorough cleaning of your ducts to clear out all that gunk.

5. Home’s Air Smells Musty

We’re all familiar with that brief but “odd” smell that flows from our vents any time we switch over from our cooling system to our heating system (and vice versa) for the first time in months. But a musty smell that’s ongoing? Yeah, that’s not normal — and it could indicate a pest infestation, mold growth, or mildew, meaning you need air duct cleaning.

6. Excess Dust in Your Ducts

Hand in a protective rubber orange glove shows clogged air ventilation grill.
Photo Credit: Evgen / Adobe Stock Free / License

A little dust won’t hurt you — most of it sticks to the air duct’s walls, anyway. The same is true for any dust and other particulate matter you may occasionally encounter on your air vents and vent covers. With a quick wipe or run of the vacuum, they’ll be clean once again.

On the flip side, an extreme buildup of dust and dirt can obstruct airflow, compromise ducts’ air filters, and trigger allergic reactions (more below).

7. Worsening Allergies

If you or other members of your family have allergies, asthma, and/or other health problems that have become exacerbated, I’d recommend having an inspection and air duct cleaning. High amounts of pollutants like pet dander, pollen, dust, and dirt can increase sneezing, itchy/watery eyes, and other allergy symptoms.

FAQ About Air Duct Cleaning

What Are Air Ducts?

Simply put, air ducts are the channels through which your home’s air is filtered, heated or cooled, and then sent back out into your living spaces. This ductwork, which is a crucial component of your HVAC system, can be located inside your home’s walls, ceilings, and/or flooring and is typically made of:

• sheet metal
• fiberglass
• steel wrapped in flexible plastic

Return ducts are the ones responsible for recycling the air in your home. They draw in the “used” air, send it through an air filter, and run it through the heating or cooling system. Supply ducts then take that recycled air and distribute it back out through vents all over your house.

How often should I clean my air ducts?

There is no set schedule on how often homeowners should clean air ducts. The National Air Duct Cleaners Association (NADCA) and the Environmental Protection Agency (EPA) advise people to only clean their air ducts as necessary. 

That being said, every household has its own needs, and if you or those you live with already suffer from allergies or asthma, for example, you may learn you need air duct cleaning services more often than the general population.

My Tip: Air ducts should be inspected annually. 

Find an Air Duct Cleaning Pro Near You

Signs your air ducts need cleaning include obvious mold, thick layers of dust and grime, and pest infestations.

Remember, the best air duct cleaners have good reviews, are licensed and insured, are members of the NADCA, promise to inspect your ducts first, and don’t offer steep “whole-house” discounts.

Home Gnome delivers the best home service experience at the click of a button. Book reliable, skilled handymen and handywomen in seconds and leave the rest to us.

Main Image Credit: Quality Stock Arts / Adobe Stock Free / License

Andrea Butler

Andréa Butler has a passion for writing, editing, and binge-watching home improvement shows. While she’s just getting started on her DIY journey, she enjoys researching new projects and testing them out. Besides aspiring to be a handier woman, she also enjoys singing and reading.