How to Identify Ductwork Problems

An efficient HVAC system can you save you loads of money in the long run and keep your home nice and comfortable throughout the year. Problems in the ductwork, however, can quickly consume your energy budget and make it hard to heat and cool certain areas of the home. If you suspect your HVAC system is not working properly, follow this short guide to help identify and fix common ductwork problems.

Abnormal Energy Bills

A sudden spike in your energy bill is a good sign that your home’s HVAC system is compromised. Leaky connectors and poor designs lead to air flow loss, which makes the system work harder to heat and cool the home. This in turn expends more energy and runs up the electricity bill.

Noisy Ductwork

Another good indication of a bad HVAC system is noisy ductwork. In rectangular ducting, these noises are usually the result of the metal expanding and contracting. It should be noted that noises are typical when the system first turns on or off. You should be concerned, however, if the noises continue while the system is running. If you hear a whistling sound, for example, you are likely dealing with vent covers that are too small for the system.

Uneven Temperatures

If you have areas of the home that are hard to heat and cool or get overly stuffy, your HVAC system probably has a leak or two. Uneven temperatures are caused by poor air flow because the system is simply losing too much air to properly do its job. In extreme cases, you will not be able to heat or cool certain areas of the home even if the thermostat is turned to its highest setting.

Finding Problem Areas

Detecting problems in the ducting is a straightforward process. The biggest issues typically include bad seals around joints, improperly seated vents, and poorly supported ducts. You might also examine the overall design of the ductwork as the installer may have made mistakes in the original installation. Look for areas that feature sharp turns in the ducting as this can significantly reduce air flow.

Feeling

You can also feel for air loss with your hands. Start by feeling the air pressure coming out of vents in multiple rooms. If you detect a difference between vents, then you know you have a leak somewhere in line with that vent. You can narrow down the location of the leak by using some incense, toilet paper, or wet fingertips. The incense and toilet paper will move or your fingers will get cold when coming in contact with the leak.

Visual Examination

Examine the ducting for any obvious signs of gaps, holes, and cracks. The most likely problem areas include connections and seams, and places where the ducting links up with the ceiling, floor, registers, and vents. For flexible ducting, ensure the pieces are not crimped or tangled.

Fixing Ductwork Leaks

Once you locate the problem area, it’s time for a little repair. All you need to repair leaky ductwork is some HVAC-grade aluminum foil, a putty knife, gloves, and a few cloths. Begin by cleaning the area with a damp cloth and keep a lookout for any sharp edges. It's recommended to use mastic for loose fittings, though foil tape can also prevent air loss. Just make sure the connection is tightened up and the screws are back in place before you apply tape. If you detect any major cracks in the ducting, you may need to replace the section with a new piece of sheet metal.