HVAC 8 in. x 25 ft. Insulated-Flex Ducting Ventilation Duct Hose

Hello Walter, Thank you for your question! This insulated flex duct is designed for general HVAC air distribution and can be used for branch runs in heating and cooling systems. However, we do not recommend using it as the main trunk line for a gas furnace system. For the main supply or return trunk, galvanized sheet metal ductwork is the industry-standard choice due to its durability, airflow performance, and compliance with most building codes. Best,

Hello Walter, Thank you for your question! This insulated flex duct is designed for general HVAC air distribution and can be used for branch runs in heating and cooling systems. However, we do not recommend using it as the main trunk line for a gas furnace system. For the main supply or return trunk, galvanized sheet metal ductwork is the industry-standard choice due to its durability, airflow performance, and compliance with most building codes. Best,

Hello! Thank you for your question. Yes, you can cut the insulated flex duct lengthwise, wrap it around a 4" rigid aluminum pipe, and reseal it with UL 181-rated foil HVAC tape. While it's not designed specifically for this purpose, it can work well as a DIY insulation wrap if the seam and ends are sealed properly to keep the insulation contained and maintain the vapor barrier. Best,

Hello Leon, Thank you for your question! Yes, this HVAC Insulated Flex duct can generally be used for residential heating and cooling applications, including supplying air to a basement area. The duct is constructed with double-ply aluminum foil and PET film layers with insulated glass wool material, helping maintain air temperature while also providing thermal and acoustical insulation. It is designed for both hot and cold air movement and is lightweight, flexible, and easy to install in tight spaces. However, all HVAC modifications and installations should be properly sized and completed in accordance with local HVAC and building code requirements to ensure safe and effective system performance. If you have any other questions, please feel free to reach out! Best, Robert Morris, Rubber-Cal Inc.

Hello Dennis, Thank you for your question! The listed 8-inch measurement refers to the inside diameter, meaning the actual airflow opening is about 8 inches. The insulation (glass wool) and outer aluminum/PET layers are wrapped around that inner core, so the total outside diameter will be larger, but it won’t reduce the internal airflow size. This design helps maintain air temperature while still providing the full 8-inch interior space. If you have any other questions, please feel free to reach out! Best, Robert Morris, Rubber-Cal Inc.

Hello John, Thank you for reaching out! To fasten an insulated HVAC tube to metal ductwork, you’ll first want to pull back the insulation and outer layer, then securely attach the inner liner to the metal duct collar using a clamp or HVAC-rated zip tie. Once that’s in place, it’s important to seal the connection with mastic or foil HVAC tape to prevent any air leaks. After sealing, simply pull the insulation and outer layer back over the connection and secure it with another tie or tape to ensure a proper finish. If you have any questions or need further assistance, please don’t hesitate to let us know—we’re always happy to help! Best,

Hello Charles, Thank you for your question! This insulated flex duct would not be suitable for use with an outdoor wood forced air furnace, as it is only rated for temperatures up to 160°F and is intended for standard HVAC air movement such as air conditioning and low-temperature ventilation. Wood-fired furnaces can generate air temperatures well above this limit, which could damage the duct or create a fire hazard. For your application, you would want a duct specifically rated for high-temperature heating applications, such as metal ducting or a high-temperature flexible duct designed for furnace or boiler exhaust or supply air. If you have any other questions, please feel free to reach out! Best, Robert Morris, Rubber-Cal Inc.

Hello Larry, Thank you for your question! The insulation in this product is made of glass wool, with double-ply aluminum foil and PET film layers. There is no indication that it contains formaldehyde. Glass wool insulation is commonly used in HVAC systems to help maintain air temperature and reduce noise. This type of ducting is typically used for residential or industrial ventilation, air conditioning, cold air supply, confined space ventilation, and other general air movement applications. If you have any further questions, please feel free to reach out! Best, Robert Morris, Rubber-Cal Inc.