HVAC systems are incredibly complex. There’s the main unit—the furnace or air conditioner—generating hot or cold air. There are the grilles and registers emitting and taking in air. Then, of course, there are the ducts that bring air to and from your central unit.
Every single element of your HVAC system has its own complexities, and your ducts are no exception. In this article, we’re going to look at how ductwork affects your energy bills.
How ducts cause energy loss
We’re not going to give you a whole physics lesson, but you’ll need to know a bit about how heat moves in order to understand how ducts cause air loss. Ducts—no matter what material they’re made of—make contact with the air around them. When that air is hotter than the air in the ducts, the ducts heat up and transfer that heat to the air inside them. The opposite is true, too—cooler air will cool the air inside the ducts.
That means that you’re losing efficiency, whether you’re heating or cooling.
The more ducts you have, the less efficient the system is; there’s more surface area exposed to hotter or cooler air. The design of your ductwork, then, is an essential part of their efficiency.
Your ducts should all run through conditioned spaces. That’s no problem here in Winnipeg—practically every house is conditioned from top to bottom, or we’d have way too many burst pipes on our hands in the wintertime.
For efficiency, ductwork should generally follow either a radial or trunk and branch design. These two designs limit the amount of space your ducts will take up—and that means your whole system will be more energy efficient.
For maximum efficiency, consider using a ductless system. While ductless furnaces don’t exist (yet), ductless AC systems can dramatically improve efficiency.
What materials you should use for your ducts
Your ducts will almost definitely be made of metal—usually aluminum or galvanized steel. These are both excellent options, though it’s a good idea to insulate them—more on that in the next section.
Fiberboard ductwork is another possibility, but it’s one we tend to advise against. While it’s suitable for energy efficiency, it can be prone to developing mould, mildew, and other contaminants; in other words, it’s not great for air quality.
Another option is flexible ductwork made of wire coils wrapped in plastic. Flexible ductwork is less expensive—it’s also far less energy efficient. This style of ductwork is prone to breakage, and every crack in your ductwork can lead to a significant decline in energy efficiency.
Insulating your ductwork
To maximize energy savings, all of your ductwork should be insulated. The most common way of doing this is through the use of fiberglass insulation—in fact, many installers will offer fiberglass-insulated sheet metal ductwork as their premium option. We highly recommend insulating your ducts.
What is duct tape for? Fans of Red Green will answer “Everything” (and they’re not wrong), but it was specifically designed for ducts. You can use duct tape to seal small holes or cracks in your ducts. In fact, we recommend inspecting your ducts at least once a year for cracks and holes. They’re fairly easy to notice (air will be blowing out of them)—you can feel along the ducts to find damage.
Need to improve your ductwork? Call Provincial!
Our HVAC professionals can install, repair, and insulate your ductwork for you. Lower your energy bill and make your home more comfortable by improving your ducts. Call us today!