If your utility bills seem high or if your HVAC system isn't heating and cooling your efficiently, a leaky duct may be the issue. Poor duct connections and holes can lead to a 20 to 30 percent air loss, which results in higher bills and less comfort in your home. Finding and sealing the leaks can solve the problem.
When to Act
The best time to check and seal your ducts is as soon as you notice a problem. Older homes, especially those that are on their second or third HVAC system, are more likely to have major leakage than newer builds. Stuffy or difficult to heat or cool rooms are often a sign of a duct problem. Check the ducts first before investing in a new air conditioner or furnace.
You should also avoid getting a new system installed until after the duct work has been checked and repaired. If you skip the duct work inspection, you may find your new system doesn't work as well as you expected. Leaky ducts can also result in more stress on the new system, as it tries to maintain the thermostat temperature. This can lead to premature break downs.
Leak Detection Methods
Start with a visual inspection of all exposed duct work in your basement or attic. Look for holes or loose joints when the blower is running. If the leak is major, you will likely feel the air rushing out. Detect minor leaks with the candle test – hold a lit candle beneath the ducts and look for flame movement from escaping air.
Unless the leak is in an easily accessible area, you may need an HVAC technician's help to find the problem. The technician will seal up your registers, creating a closed duct system. They'll then blast air into the duct work while using a diagnostic machine to measure air loss and track down the area that is leaking.
Whether your duct repair is a do-it-yourself project or one requiring a professional depends on the location. You can purchase and apply duct sealant on your own to exposed joint leaks. You simply brush it or spray it on and then let it dry.
Major leaks or those inside inaccessible areas require the professional touch. The registers are blocked, and then the HVAC technician fills the duct system with an aerosol sealing spray. The aerosol sealant only clings to the sides of the duct work, sealing any leaks but leaving the rest of the duct open so air can flow to the registers.
Although fixing the common duct leaks in exposed pipes and around registers can be a quick weekend DIY project, it's best to plan for a professional inspection if you want to realize the biggest cost and energy savings that is possible.
For more information, check out companies such as R & B Heating & Air Conditioning.