If you’ve got something like this in your attic, then a good portion of your utility bill is being wasted. Unfortunately, sights such as this are more common than you might think. Studies have shown that a typical house may lose around 30% of its energy because of leaky ductwork and my analysis have shown that this may be an underestimate.
A typical heating/air conditioning system contains a blower capable of moving around 1500 cubic feet per minute (CFM) of air. Normally, the air resistance and dampers in all the different sections of duct even out the flow so that each room might receive about 100 to 150 CFM of air. But when a duct has fallen off, like shown here, the resistance to air flow is much less because the air doesn’t have to travel through all the ductwork. Because of this, one detached duct may allow 300 CFM of air, or about 20% of the total system capacity(!) to escape. In fact, that may be an underestimate of the losses.
Unfortunately, the situation is often much worse. During the winter, the warm air in your house will rise up through your ductwork and out the leaky ducts in the attic. So you are losing energy round the clock.
If you ever feel a cold draft coming out of your heating registers during the winter, especially when it’s windy outside, chances are you have leaky ducts somewhere. Or, if you find that you get very poor airflow AND cold drafts, that’s almost a guarantee of a detached duct. Find that in the attic and attach it properly. Or, if you’re not “handy”, hire a professional HVAC company to come in and check out your ducts.
So before you spend thousands of dollars installing a new heating/cooling system, you might spend a few minutes in your attic looking for bad ductwork. Fixing a single problem like the one pictured above can increase your system’s efficiency as much as installing a typical high efficiency system!