Although national building codes currently do not require that HVAC venting systems obtain a UL-1738 listing, the safety benefits of selecting such rigorously tested products for flue gas venting applications are indisputable and set the groundwork for uniform and strict standards nationwide.
What is UL-1738?
UL-1738 is the “US standard for venting systems for gas-burning appliances categories II, III, and IV.”[1] Acceptable venting materials listed to UL-1738 include plastic, mantellic, flexible and rigid single/double wall concentric systems. To achieve this listing, products are performance tested, and must adhere to specific standards for construction, labeling and installation instructions. In short, a UL-1738 listing indicates top of the line venting products, with the highest probability of success.
Safety and Durability
UL-1738 listed products must successfully pass a variety of environmental tests, meant to mimic environmental stress that venting installations face in real life.
- Low Temperature Testing: Products must complete a drop test at -20⁰C without any type of damage.
- High Temperature Testing: Venting systems must pass a performance evaluation while operating 70⁰F higher than the rated temperature.
- UV Testing: Equipment must pass inspection after light and water conditioning (replicating UV rays from sunlight and rain).
- Pressure Testing: Systems are tested at 250% of rated operating pressure to ensure durability.
- Leakage Testing: UL-1738 products require performance tests to ensure no leakage occurs.
Standardizing Installation and Service
UL-1738 equipment must meet or exceed acceptable standards and follow thorough protocols, designed to ensure consistency across HVAC installations.
- Clear Labels: Print labels must be present on all pipes and fittings and must be legible regardless of product orientation.
- Installation Instructions: Thorough installation instructions must accompany all products listed under UL-1738.
- Compatible Systems: There can be no mixing of multi-manufacturer components in a single vent system, ensuring that only the intended products are used.
- Nationwide Certified Materials: A nationwide standard eliminates confusion or improper venting installations, regardless of location.
Bottom line – it’s not worth taking a chance on venting products that aren’t UL-1738 listed. UEP is proud to offer Centrotherm’s line of polypropylene piping which offers many benefits over PVC and CPVC, including the fact that it has earned the UL-1738 listing. Check them out here or contact UEP today for more information on our products!
[1] https://www.centrotherm.us.com/FAQ/Why-UL-1738.aspx
