Duct Sealing

Properly sealing ductwork results in several benefits. It improves comfort by increasing the rate at which air is delivered to a space; it can prevent safety problems caused by carbon monoxide gas leaking from water and space-heating equipment; and it improves indoor air quality by reducing the infiltration of dust, humidity, and outdoor fumes and odors. It also saves energy. The most cost-effective time to seal ducts is when an HVAC system is first installed in new construction, because the ducts are easily accessed. However, ductwork can also be sealed in existing buildings.

Duct sealing may be justified on the basis of its non-energy benefits; however, its cost-effectiveness based on energy savings alone is unclear. Research from Lawrence Berkeley National Laboratory shows that 10 to 20 percent of the air from an HVAC supply fan is wasted through leaks in commercial buildings. At 15 percent leakage, buildings must use 25 to 35 percent more fan power to distribute air than if there were no leakage. Stopping this leakage could create significant dollar savings in certain climates. However, the cost of sealing ducts in commercial buildings, particularly in existing ones, is not well established and depends on many factors.

What are the options?
How to make the best choice
What’s on the horizon?
Who are the manufacturers?
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