According to Energy Star, a typical house loses about 20 to 30 percent of the air that moves through the duct system due to leaks, resulting in higher utility bills and discomfort for house occupants. Unbalanced air pressure can further add to your duct leak energy loss. Regular inspection and maintenance of your duct system will save you money and reduce energy consumption.
Why do duct leaks waste so much energy?
Duct leaks occur in every home due to holes, disconnected ducting and leaky seams. Although leaks inside your conditioned space still waste energy and cause discomfort, they’re not as bad as leaks that occur in unconditioned spaces.
Air leakage inside the conditioned space of the home will cause a positive indoor air pressure and this will force your conditioned air out. Air loss outside the home may cause a negative indoor air pressure which can result in unconditioned air from outside being drawn into the home which compounds duct leak energy losses.
Duct leaks mean that your HVAC system has to work harder to keep your home comfortable. If you have a pressure imbalance, the added strain on your HVAC system can cause components to fail sooner than they would otherwise.
What can you do about duct leaks?
The first step is to measure your indoor air pressure with a manometer to establish whether you have a negative or positive indoor pressure. You can use a duct leakage tester to measure the airtightness of your HVAC ductwork.
When ducting is hidden, it may be difficult and costly to reach. If you have a limited budget, it’s best to focus on those areas that will give you the best bang for your energy saving buck.
Focus on areas near the HVAC equipment where pressure is highest, at the boots where unconditioned air can leak in and on ducts located in unconditioned spaces like crawlspaces, unconditioned attics, garages and basements.
Start with a visual inspection to see if there are obvious leaks or disconnected ducting. Once you have located leaks, get together your foil tape, mastic and a brush. Clean ducts and ensure they are free of dust and oil. Wrap the leak with foil tape and press down.
Mastic is a good option for leaks that are ¼-inch or smaller. Use the brush to paint the mastic over your foil tape. Ensure your mastic is about “nickel thick”.
Get a professional to inspect and maintain your ducts regularly if you are serious about reducing your energy consumption. Keeping your HVAC system in good working order will help to reduce energy costs, keep your home comfortable and ensure that your equipment lasts longer.