Most homeowners recognize the importance of having their furnaces and air conditioners maintained by a professional. Regular maintenance will save you countless dollars by preventing more serious problems from occurring. Yet what many people fail to understand is that such maintenance extends beyond just your HVAC appliances themselves.
A duct system must also be protected against problems, lest it undermines the efficiency of both your furnace and your air conditioner. Air leaks represent one of the common — and the most damaging — duct problems. This article will take a closer look at how duct systems develop leaks, as well as the negative effect such leaks can have.
The easiest way to think of a dust system is as a single, continuous network of metal ducts, usually located above the ceiling of your home. This view makes it easy to overlook the fact that a duct system consists of many different pieces, each of which has been painstakingly joined together to negotiate the structural contours of your home.
Unless your home happens to be brand new, this process of building the duct system likely took place years ago, if not decades. The contractor responsible for installing it used one of two methods — either metal duct tape or a substance known as mastic — to attach one piece of duct to the next.
Of these two types, mastic tends to exhibit better performance as the years go on. Duct tape, by contrast, displays a marked tendency to come loose as its adhesives dry out. Given enough time, putty-like mastic will also begin to grow brittle, cracking and crumbling away. In either case, this process of degradation creates places where air can escape out of — or into — your duct system.
Such duct leaks reduce the efficiency of an HVAC system. As a result, your furnace or air conditioner will have to work harder in order to accomplish the desired temperature change. This, in turn, leads to a greater amount of wear and tear on your HVAC appliances, increasing the risk of burnouts or component failures.
When identifying duct leaks, HVAC contractors will always specify which half of the system the leak has occurred on: the supply side, or the return side. The supply side involves the ducts responsible for delivering conditioned air from your furnace and air conditioner into the rooms of your home. Return side ducts, by contrast, conduct air from your home back to your HVAC appliances for further conditioning.
The supply side of the system tends to operate under what is known as a positive pressure differential. In other words, the pressure of the air flowing out of your HVAC system is greater than the pressure of the air inside your home. This positive pressure differential will act to force conditioned air out of your ducts through any cracks that may be present.
The opposite phenomenon occurs on the return side. Here a negative pressure differential exists. This will cause air from crawl spaces, attics, and other unheated parts of your home to be sucked into the duct system. Your HVAC appliances will then have to work harder to offset the negative impact such air has on the temperature of its supply air.
Return side leaks also result in dust and other forms of airborne debris getting into the duct system. Such debris will cause your air filter to become clogged up much faster. And because the filter won't be capable of capturing all of it, this debris will also result in poorer air quality inside your home. Allergies, asthma, and other breathing problems may result.
Duct and HVAC Experts
To keep your HVAC appliances running at peak efficiency, be sure to have your ducts periodically inspected for any signs of leaks. To learn more about how to eliminate duct leaks, please don't hesitate to contact our heating and cooling pros at After Hours Heating & Cooling, LLC.