Your air ducts are a part of your home's HVAC system and work to move chilled or heated air, depending on the exterior temperature, to various rooms throughout your home. This means that they are essential to the operation of both your air conditioner and your furnace: blocked or dirty air vents can represent a hurdle to their ability to control the climate within your home. Understanding some of the warning signs associated with air ducts that have become clogged with dust and other debris can help you determine when you should talk to an HVAC contractor about cleaning them out.
Increased Energy Bills
One of the first signs of clogged duct work that you may notice is a general increase in your monthly energy bills without a corresponding change in your thermostat's temperature or the use of other appliances in your home. Since your HVAC system is one of the leading energy consuming appliances in your home, any sort of blockage in the duct work will cause a significant bump in your energy bills. Plus, your HVAC system will not be able to heat or cool your home due to restricted air flow, leading to longer operation times.
Persistent Bad Smells
Furthermore, another sign that your duct work desperately needs to be professionally cleaned is if you notice that there is a strong, unpleasant smell that permeates most of your home. If this smell won't disappear no matter how much you clean and disinfect, it likely is coming from your air vents. This can be because of condensation and moisture buildup, which can contribute to mold growth in the ducts themselves. However, it may simply be the stale smell of years of accumulated dust, pollen and pet dander as well.
Allergy Symptoms and Mold Growth
Expanding on the above point, you should also watch out for other signs of mold growth in your duct work, which can be a serious health risk. Allergy symptoms like coughing, runny noses or eyes, and even rashes and skin conditions can all point to mold growth in your duct work, especially if you have never experienced such problems before or if they are happening out of season. You may also want to consider removing your vents and inspecting the interior of your duct work for signs of mold: it can take many colors, but is most commonly dark green or black, and looks similar to a large dirt stain.