As an expert in the HVAC industry, I have seen many different types of ducts being used in homes and buildings. However, after years of experience, I can confidently say that sheet metal is the best choice for ductwork. Not only is it durable and easy to clean, but it also prevents the growth of mold and bacteria due to its non-porous nature. Sheet metal ducts are typically made of galvanized steel or aluminum, making them strong and long-lasting. The smooth surface of these ducts makes them easy to clean, but it's still important to have them professionally cleaned from time to time to maintain good air quality in your home. One of the main advantages of sheet metal ducts is that they are not porous, which means they are less likely to promote mold growth.
On the other hand, flexible ducts, which are usually installed in one continuous piece, can develop leaks at the seams when connected to rigid sheet metal ducts. It's crucial to install flexible ducts correctly to avoid any restrictions in airflow. Improper installation of flexible ducts can lead to tears, bends, and abrupt turns, which can cause problems with your HVAC system and even lead to equipment failure. That's why it's essential to hire a professional for the installation process. The most commonly used material for ductwork is galvanized steel. It's strong, durable, corrosion-resistant, and readily available.
It can also be easily molded into different shapes and welded with similar materials. When it comes to air carrying capacity, round ducts are recommended over rectangular ones. They also have lower installation costs, which can result in significant savings. However, if you have limited space, rectangular ducts may be a better option as they are more flexible and can fit into tight spaces. Another material that is resistant to corrosion caused by moisture is aluminum.
While it's more expensive than galvanized steel, it has the advantage of being lightweight. However, it's not as strong and has limitations such as thermal expansion and weldability. In low-pressure systems, fiberglass ducting is commonly used. These ducts are insulated with fiberglass and have a metal foil coating that acts as a vapor barrier. This insulation prevents condensation from forming, making it suitable for underground duct systems. Fiberglass ducts are constructed with fiberglass supports joined together by resin.
The outer surface is covered with aluminum foil, while the inner surface in contact with the air flow is not as smooth as metal. These ducts are often used for heating and cooling but are not recommended for ventilation. One of the advantages of fiberglass ducts is that they are inherently insulating. However, they must be constructed with care to ensure they are airtight. Any cracks or gaps can lead to erosion of the glass fibers over time, compromising the insulation value of the duct. The most convenient type of ductwork to install is flexible ducting.
These round tubes are made of steel wire propellers covered in flexible plastic and are also surrounded by insulation to maintain the desired temperature of the air. They are the second least expensive option and are perfect for tight or awkward spaces where rigid ducting would be challenging to install. The flexibility of these ducts allows them to be folded around fixed structures, making them suitable for almost any space. However, they are prone to twisting and bending, which can restrict airflow and decrease the efficiency of your HVAC system. The ridges on the inside of the ducts can also reduce airflow slightly.
