According to the US Department of Energy, the average HVAC duct system is approximately 60 percent efficient. An underperforming ductwork system can lead to many problems including increased energy costs, hot and cold spots throughout the house, unnecessary wear and tear on your HVAC system and poor indoor air quality.
The overall performance of an HVAC system can be significantly compromised by poor duct design. Proper ductwork design ensures the level of air flow that your HVAC system needs to operate efficiently and provide the comfort you want and expect. Here are the most common ductwork design mistakes that affect the function of your HVAC system:
Improper Duct Sizing
A lot of factors affect the proper sizing of ductwork. Factors such as the type of air system, load requirements of different areas, location of the ducts and equipment, as well as materials used to construct them, have high importance in the duct sizing process. If ducts are too small, they won’t be able to efficiently heat and cool different areas throughout the building, no matter how powerful your furnace and air conditioner are. On the other hand, oversized ducts will decrease the efficiency of the system and can cause uneven air distribution in some areas.
Poor Ductwork Layout
After ductwork sizing, layout mistakes are the next most common HVAC design mistake. Layout problems often result from poorly located equipment. When the location of HVAC equipment is not discussed in the planning phase, long runs of ductwork may result. Ductwork runs that are too long and elbows that are too sharp or too numerous prevent smooth movement of air which will decrease the ability of the HVAC equipment to move air consistently throughout the space. In order to minimize bends and avoid long duct runs, the HVAC equipment needs to be centrally located. That’s why it’s essential to involve knowledgeable HVAC design professionals in the early stages of construction projects. Through collaboration with your architect and contractor, an HVAC design professional can ensure that your duct layout is accurate and efficient.
Insufficient Returns Vents
To maintain balanced air pressure and air movement, your duct system needs return vents for air to be pulled back into the HVAC system. Not providing enough returns is a common ductwork design error that leads to comfort complaints and a reduction of inefficiency. Without enough returns, you end up with poor airflow and unbalanced air pressure. Therefore, having enough return vents is another important factor in maintaining adequate airflow in an HVAC system.