The size, layout and condition of a building’s ductwork are much more important to a central HVAC system than most people realize. Ductwork that is improperly designed or installed can create major issues that prevent an HVAC system from heating and cooling nearly as effectively as it should. The same is true if the ductwork is old and has lots of places where air can leak out. Learn more about the role ductwork plays in efficient and effective heating and cooling in your home.
How Ductwork Design Impacts Airflow
To work effectively, a central heating and cooling system must always have a specific volume of air circulating through it. The volume of air or airflow rate an HVAC system needs to work properly depends on the size of the system and your home. For an HVAC system to have sufficient airflow, the ductwork system must be properly sized and designed in a way that allows the blower to move air through the system most effectively.
Undersized ductwork creates issues with high static pressure, which is when the air encounters greater resistance as it moves through the ducts. High static pressure will always make an HVAC system heat and cool less effectively since it essentially makes it impossible for the system to circulate the volume of air it needs to operate at its peak efficiency. When the static pressure is too high, it causes air to basically back up inside the ductwork. This leads to the blower needing to work harder to move air throughout the space, which reduces the efficiency of the overall HVAC system and will usually also decrease its lifespan.
Oversized ductwork is less of an issue unless the ducts are much too big, but it can still lead to increased energy usage and limit how much hot or cold air the HVAC system can circulate. If the ducts are too big, there generally won’t be enough pressure in the duct system for the blower to properly distribute the volume of air it needs to heat and cool effectively. This means you’ll have much less air blowing out of your vents, leading to it taking your HVAC system much longer to cool or heat your home each time it runs.
In addition to sizing, it’s also important that the duct system is designed so that most of the ducts run in as long and as straight of a line as possible. The air flowing through a duct system has to change direction at every branch or bend. These changes of direction also create more resistance, which again makes it more difficult for the blower to properly distribute air around the building.
Why Duct Maintenance Is So Important
To get the most out of your HVAC system and keep your energy bills as low as possible, you also need to have your ductwork inspected and maintained regularly. In terms of maintenance, the two most important tasks are regularly cleaning the ducts and resealing them as necessary. The dust and debris that naturally collect inside air ducts also create additional resistance that causes the static pressure to be higher than it should be. The best way to avoid this is to have all of your ducts professionally cleaned once every few years.
Duct sealing is something that should typically be done at least every 10 years. The mastic or foil tape used to seal between each piece of ductwork tends to loosen over time, which leads to lots of air leaking out. Leaky ductwork is one of the bigger issues an HVAC system can have since it can reduce the system’s efficiency by 20-30%. This means that the HVAC system will use lots more energy than necessary. It will also experience far greater wear and tear that can shorten its lifespan since it will need to run for much longer to fully heat and cool the home. The fact that duct leaks can lead to such a major decrease in efficiency is why you should make sure to have your ducts professionally inspected at least every few years so that you know if there are any leaks that need to be resealed.
Simply Mechanical is a locally-owned HVAC company that provides expert heating and cooling services in Littleton and the Denver Metro area. Our team of NATE-certified technicians has years of experience in all types of HVAC services including repairs, maintenance and installation. Whether you need to have your ductwork inspected or require any other heating or cooling service, contact us today to get the expert assistance your home and family deserve.
