ASHRAE Standard 15 has released Addendum A to the 2024 standard, further clarifying ASHRAE's position regarding vertical A2L refrigerant piping, and the fact that they do not need to be installed in rated ventilated shafts. The new Shaft Alternative clarifies that, as long as the refrigerant piping has been tested to section 9.13, a shaft is not required. Section 9.13 of ASHRAE 15 has requirements that are very similar to conventional manufacturer requirements for refrigerant piping, and therefore should not impact installations. DXS does recommend that engineers and installers review section 9.13 to ensure compliance, as not all manufacturers may have requirements up to that standard.
This is a great and long-awaited clarification by ASHRAE 15, though it should not result in too many changes for anyone already complying with Shaft Alternative B of ASHRAE 15 2022 or 2024 to avoid the need for shafts. Of course, this now means piping through occupied spaces no longer needs to be evaluated for refrigerant concentration compliance.
Warning: if a project volunteers to use a shaft, then the shaft still needs to comply with ASHRAE’s ventilation requirements. However, ASHRAE 15 is also working on another Addendum that would eventually remove those requirements.
To view the full addendum, please click here.
