If you notice strange noises form your ducts, visible damage or tangles, or you experience uneven temperatures throughout your home, you may need to get your air ducts evaluated. 

1. You can hear strange noises from the ducts! If this happens, you have two options. You are about to become the subject of a horror movie or your ductwork is dirty and damaged. The latter is a much more realistic scenario and the sounds you may be hearing could resemble a clamoring or a rattling. This could also mean that the duct are loose and in danger of falling.Another sound you might be hearing is a faint whistling. This is the air passing through them if they are leaky and have holes. All of the situations described above will require you to call in a professional HVAC technician for a ductwork modification. Except for the horror movie scenario. You’re on your own. We joke, of course.
2. The ducts are damaged or tangled. You can actually perform a visual inspection of the ducts yourself. Are they worn down in any way? Can you see any damage caused by time such as holes? Maybe some sections are now separated from the others or they are about to fall off?If you notice any damage whatsoever, please call a technician to solve this problem for you. Old ducts that are also in disrepair can harm your whole HVAC system.
3. Uneven temperatures in the house. This essentially means that some of the rooms are cold while others are hot. When that happens, the ducts might not be well sized for your house. Or they could be leaking or obstructed by something. Every one of these problems means you will have to schedule an appointment with a professional HVAC team for a ductwork modification.

1. Your utility bills are very high – since the ducts cannot transport the air in a proper manner, then your HVAC unit needs to work a lot harder to cool or heat your house. That means it uses more energy. Hence your higher bills.
2. The house takes a long time to cool or heat – if this is happening, the air duct might be malfunctioning.
3. After you turn on the air conditioner, the rooms are dusty – the air ducts suck in dust and debris if they have leaks. This then gets blown back into the house when you turn on the AC.
   

If a duct system is not sealed properly, some 20% of all the heating and cooling that’s supposed to come into your house or building will actually end up in the attic. Not to mention that the older your house is, the worse it gets. Old homes actually lose up to 40% of their efficiency because of faulty duct work.

But what happens to the ducts? They simply get worn out. Hot or cold air gets delivered through them all year long which makes them shift, move, wear and tear. Apart from that, there could be some debris that is making it difficult for the air to move through them. All of this needs to be addressed.

Most homes have ductwork that lasts 10 to 15 years before problems arise. Have your ducts replaced if they are over 15 years old to prevent major issues such as pests, gaps, or collapsed sections. By keeping an eye on the HVAC system, you can ensure that your home remains comfortable and prevent drafts or stuffy areas.

Once you’ve determined that your duct work is faulty, you will have to choose between repairing it and replacing it altogether. If you can still perform a few good repairs, do them. There’s no need to go for a replacement which is pricier.

However, there are a few situations in which a duct work replacement is absolutely necessary.

• Your ducts are made of very cheap materials. This could mean they will break down multiple times and will end up costing a lot more than the replacement
• The system is older than 10 or 15 years. This is usually the breaking point when every duct work starts to slowly deteriorate.
• You’ve discovered the plastic ducts are covered in mold. Cleaning them is not a solution in this case. But if they are made of metal, you can get them professionally cleaned.

Vent Inspection:

• Inspect your registers one by one. Are they filthy? Clean them.

        Then go back a month later. 

• Do you see a streak of dirt or dust at the registers? IF so, you may have a leak.

Room-by-room inspection: 

• You will need to turn on the HVAC system to run air through the vents.
• Make sure all the interior and exterior doors are closed.
• Close all windows. 
  
  Then
• One by one, crack open each interior door of your house.
• If you notice your doors moving, check your air ducts as there may be a problem with air pressure.