Question: How do I know if my ducts are leaking? How can this affect my energy bill?

Answer: Good question! Here’s all you need to know about duct systems, the dangers of leaving a leaking duct, and the appropriate steps to take when checking for leaks.

What is a duct system?

The DoE describes a duct system as a network of tubes made of sheet metal, fiberglass board or flexible plastic and wire composite, located in the walls, floors and ceilings. Used in both residential and commercial capacities, ducts are essentially the passage ways that carry the flow of cold or hot air from the central air source to the rooms the air is intended to heat or cool.

Unfortunately, according to HVAC 10-30% of cooled and heated air circulated is wasted because of leaks in the system meaning that it’s really important for your business to conduct proper duct maintenance and check for leaks on a regular basis.

Duct leaks can be costing you more than you think

You might not know it, but leaks are the primary source of energy loss in HVAC systems. In fact, a study performed by the Indoor Environment Department at Lawrence Berkeley National Laboratory regarding “Duct system performance and energy losses in large commercial buildings suggests that up to one third of energy losses can be attributed to air leakage in multi-storied commercial buildings with floor spaces more than 2,000 square metres.

Fixing leaks in your system, however, can help reduce wasted energy by 5%, lowering energy costs and saving your business money that was being swept away into thin (dirty) air. A leak-free duct system also means the creation of a healthier work or home environment. Leak free system provide better air circulation, keeping your employees at a comfortable temperature and breathing in clean air, free of  dangerous dusts, molds, microbes or even radon gas.

How can I tell if I have a leak in my system?

Taking a look at the supply and return plenum, the starting collars, the fittings around the duct runs, splices and areas where ducts connect to supply registers is a good place to start checking for leaks. Once you’ve done that, check to see if your system shows any of these signs of poorly performing ducts, compiled by ENERGY STAR:

  • Bills that peak during summer and winter months
  • Rooms that are harder to heat and cool than others
  • Duct systems that are located in an attic, crawlspace or garage
  • Tangled or kinked flexible ducts

Bellows Plumbing adds that discolored fiberglass is a sure-tell sign you have a duct problem. Fiberglass, often used as duct insulation, is yellow or pink when installed, but once exposed to accumulated dirt and debris due to air leaks, it can quickly turn to a foreboding shade of brown, or even black.

If you do find a leak in your system, don’t panic (and don’t rush out to buy the cheapest duct tape you can find). Use industrial standard tape, or indoor/outdoor sealant that works on all types of ducting to patch things up. Mastic and butyl tape used at connection points can also help prevent future leaks. Don’t forget that’s it’s important to have your ducts checked every year. Hiring a professional HVAC contractor can help you detect and repair any leaks that might exist.

Want to learn more about energy savings for your business? Check out these great energy rebates for energy-efficient equipment and start saving on energy costs, today.

Questions or comments about duct leaks? Leave them below!

image credit:Howard 33