Frequently Asked Questions

• What is the difference between AIR DUCTS and AIR CONNECTORS?

  Air ducts must pass 15 tests of the UL181 Standard for Safety for Factory Made Air Ducts and Air Connectors.  However, air connectors are required to be pass only 12 of the 15 tests.  Therefore, most models codes and the National Fire Protection Association (NFPA) require that air connectors shall not be installed in lengths greater than 14 feet.  An installer may not increase this length by using a splice between 14' sections of air connectors.  The installed length of Air Duct is not restricted. 

   

• Can Flexible Air Ducts or Connectors be used to vent clothes dryers?

  No.  The International Mechanical Code states that “Exhaust ducts for domestic clothes dryers shall be constructed of metal and shall have a smooth interior finish.” Additionally, most if not all appliance manufacturers also state this in their installation instructions.  Often, the clothes dryer warranty is void if it is not vented properly.  None of our flexible duct products can be used to vent clothes dryers.

   

• Can Flexible Duct be exposed to ultraviolet sunlight?

  No, flexible duct must be protected from the weather, including sunlight. In the late 1980’s, manufacturers of insulated flexible duct discovered that the products with gray polyester jackets could fail when exposed to direct or indirect sunlight. The ultraviolet rays in the sunlight would break the chemical bonds in the gray polyester jackets causing them to disintegrate over a period of several years. To alleviate the problem, manufactures began using black polyester jackets. The carbon black used to color the black polyester jackets has an inherent resistance to ultraviolet light. Since the change, the problem has been eliminated. However, most manufacturers, Hart & Cooley included, still require that insulated flexible duct of any type not be installed in areas with direct or indirect sunlight. At Hart & Cooley, we are confident of the quality of our flexible duct products. We back this confidence with a 10-year warranty, the longest warranty coverage currently available in the flexible duct market. For additional information contact the: Air Diffusion Council, 1000 E. Woodfield Road, Suite 102, Schaumburg, IL 60173-5921 (847) 706-6750 www.flexibleduct.org

   

• Can screws be used to fasten flexible duct core?

  Hart & Cooley does not recommend screws be used to fasten the polyester core of the air ducts because they weaken the polyester. Polyester is a very strong material as long as there are no holes or tears in it. As soon as a tear or hole is introduced, it’s strength drops. To maintain our UL approval status, our air ducts must pass a tension test (25 pounds hanging from one end of the duct), a torsion test (one end rotated 180° or to 25 foot-pounds whichever comes first) and then a leakage test. In all of these tests, both ends must be connected to collars per our installation instructions. Flexible duct connected with screws would not pass these tests.

   

• Are flexible Air Ducts plenum rated?

  The plenum rating test, UL910, came about for materials (primarily cables) that did not lend themselves to testing per UL723 (surface burning test). However, the intent was the same: to limit the flame spread and smoke developed in building materials. Therefore, per Underwriters Laboratories (UL), our UL181 classified air ducts are plenum rated because of the UL723 requirement.

   

• Must I use UL-Listed Duct Tape, Mastics and Clamps?

  Yes.  Our installation instructions are in full compliance with UL and ADC standards.  As such, only duct tapes, mastics and non-metallic clamps that are listed and labeled according to the UL-181 standard can be used.  Metallic clamps are also allowed.  The use of beaded sheet metal fittings is also required. 

  • Duct tape must be marked "UL181B-FX".  (established October 20, 1995.)

  • Mastics must be marked "UL-181B-M".  (established October 20, 1995.)

  • Non-metallic clamps must be marked "UL-181B-C".  Limited to 6" w.g. positive pressure.  (established May 15, 2004.)

   

• Do you have Material Data Safety Sheets (MSDS) for your products?

  No, because Hart & Cooley products meet the definition of an "article", they are not subject to the OSHA Hazard Communication Standard. Therefore, Material Safety Data Sheets are not required.  Under Section 1910.1200 (b)(5) of the OSHA Hazard Communication Standard an article is defined as any manufactured item:

  (1) which is formed to a specific shape or design during manufacture,

  (2) which has end-use functions dependent in whole or in part upon its shape or design during end-use, and

  (3) which does not release, or otherwise result in exposure to, a hazardous chemical under normal conditions of use.

   

• I have another Question

  Visit our Tech Corner for additional resources that cover a variety of topics or

  Contact our Product Application Engineer, Keith Page at 1-616-395-2839 or e-mail at: keith.page@hartcool.com.