You can buy a brand new, state-of-the-art AC unit and never get the full efficiency that you are supposed to get out of it if your ducts are not running like they should. The problem with ducts is that they are constantly subjected to a cycle of heating and cooling. During the summer, they heat up with the ambient temperature until your AC kicks on, then the air running through the ducts will cool them down. The reverse happens when your furnace kicks on during the winter. As your ducts heat up, they expand and then contract as they cool. The end result of this constant cycle is that the seals on your joints will give out. When they do, you have a real problem.
The Story of Leaky Ducts
When the seals fail, they allow air to leak out of your ducts, and the more air that leaks out of your ducts, the smaller the volume of air is that is available to heat and cool your home. This means that your AC unit has to run longer and harder than it should have to in order to cool your home. In fact, leaky ducts can reduce your system efficiency by up to 40%. In other words, if you start with a system that is 98% efficient, leaky ducts can cut that efficiency to 58%. To avoid paying too much, you need to properly maintain your ducts.
Inspecting and Repairing Ducts
If you have exposed ducts in your attic or basement, you can inspect and repair your ducts in this way:
- Turn your thermostat to the "fan" position.
- Get access to your ducts.
- Light a stick of incense and run it along your ducts.
- Mark any place where air leaking from your ducts disturbs the smoke from your incense.
- Inspect the full length of your ducts in this way.
- Turn your thermostat to the "off" position.
- Paint a thick layer of duct mastic over all the marks you made.
- Give the mastic time to cure before you turn the thermostat back to the "on" position.
Leaky ducts should be within the abilities of most homeowners, but if you have ducts enclosed behind the drywall of your home, or you don't trust yourself to repair your own ducts, you can call in an AC technician, like Shivani Refrigeration & Air Conditioning, to inspect and, if necessary, repair your ducts for you. Either way, you stand to save a lot of money on your cooling costs by inspecting and repairing your ducts.