High Temperature

Hot Air Ducts – Types and Classes

black hose coiled up

Of all the resources available to us, hot air is perhaps one of the most simple yet important of all. Hot air is used in a variety of applications. In residential and commercial settings, hot air is essential in air conditioning as it can help to heat up a very cold area. In applications involving heavy industry, mass quantities of hot air are necessary to provide motion for turbine engines or to help mold plastic materials. But hot air is not always the easiest element to harness and direct. In order to control the flow of hot air, one needs to employ the use of a hot air duct .

Hot air ducts are integral parts of heat-related applications because they are designed to withstand the elevated temperatures. The exact temperature of hot air can vary from one application to another and it can range between ambient to infinity (we are not being facetious, rather trying to make a point here.) In other words hot air is a relative term. Due to the large variation in high temperature definitions across the industrial world, there are a variety of different hot air duct products available on the market. Hence when we speak of hot air, we speak in exact numbers in order to match the application with that of a flex duct.

“Aluminum Flex 400”

$66.60$143.65
Temperature Range: -100°F to +400°F Sizes I.D. (in.): 2, 3, 4, 5, 6, 7, 8, 9, 10, & 12

“PVC Flexduct General Purpose Blue”

$24.36$442.50
Lead Time 4-6 Weeks Some Sizes Out of Stock Temperature Range: +20°F to +160°F Sizes I.D. (in.): 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, 9, 10, & 12

“PE Flex Ultra Flexible”

$42.38$242.50
Temperature Range: -40°F to +140°F Sizes I.D. (in.): 2, 2.5, 3, & 4

“Neo 300”

$98.04$387.60
Lead Time 4-6 Weeks Temperature Range: -40°F to +300°F Sizes I.D. (in.): 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, & 8

When looking for the appropriate hot air ducts for a particular project, it is very important to consider the type of material that a hot air duct is made from. Different materials can handle different temperatures. Typically, hot air ducts can be made of materials such as PVC, thermoplastic rubber, silicone, and metals such as aluminum and stainless steel.

PVC material is often used to make hot air ducts that are ideal for commercial grade heat applications. They generally tend to have a high temperature range limit of 180° F. PVC hot air ducts are very affordable when compared to hoses made of other compounds. They also provide great levels of flexibility, allowing them to flexed at greater rates. While PVC is good for transferring commercial level hot air, it also brings the added benefit of being resistant to certain oils and chemicals.

pe flex

Another very common type of hot air duct material is thermoplastic rubber. The term “thermoplastic” refers to the fact that the rubber is made using plastics in its body. These hoses are used in common applications like street sweepers and hood ranges. In terms of hot air related applications, the thermoplastic hot air ducts edge out their PVC counterparts thanks to a maximum temperature range of 275° F. Although a thermoplastic hot air duct may lack the long-term flexibility of PVC hoses, it makes up for it with great durability against physical and environmental abrasions.

Hot air ducts made of silicone are high-end products that are used in a variety of applications. Silicone is a synthetic compound that possesses very low levels of thermal conductivity, chemical reactivity, and toxicity. Due to these characteristics, one can find a silicone hot air duct being used in a large variety of extremely high temperature applications, such as in automotive exhaust systems, plastics processing, glass drying, and brick kiln ventilation. The main attraction to a silicone hot air duct lies within its very high temperature range. Hot air ducts made of silicone can normally handle temperatures ranging up to 550° F. In some cases, depending on the makeup of a specific hot air duct, the range can be even higher up to 750° F.

Metal hoses are usually prized for their durability, but they also bring a superior level of temperature resistance along with them. It is very important to know what kind of metal is used to make the hot air duct. Aluminum is a very popular alloy that is lightweight, flexible, and durable. They are well suited for light and medium duty applications that involve higher than normal temperatures. Aluminum hot air hoses can transfer hot air up to 400° F. Aluminum ductwork can often be found in factory ventilation units.

Another type of metal that is popular for use as a hot air duct is stainless steel. This type of metal is used for extreme applications. If an application needs hot air ducts that can survive extremely high temperatures in rough abrasive environments such as factory furnaces and industrial pollution control, then stainless steel is the metal of choice. This alloy can also endure more physical harm than other hoses. They can handle hot air reaching temperatures as high as 700° F. Stainless steel is also known to be mixed with a titanium allow in certain products, bringing the operating temperature range up to 1650° F.

PE flex ultra flexible

Since hot air can be involved in a variety of different applications, there is an accompanying range of hot air duct options for people to choose from. The types of hot air ducts mentioned above are among the most popular and widely used varieties. Be sure to know the temperature of the hot air involved in an application before making a decision on a particular hot air duct.