According to the public review page, the purpose of this standard is to “minimize the risk of personal injury by providing minimum requirements for the design, construction, installation, inspection, and maintenance of the mechanical refrigeration systems and volatile direct refrigeration systems specified in Clauses 1.2.1 and 1.2.2.”
Changes to B52 are as followed:
- Clause 1.2.3 d), which excludes air conditioning in private residences from the scope of B52, has been deleted.
- Clause 3 has new definitions for air circulation, connected spaces, effective dispersal volume, effective dispersal volume charge, independent circuit, mitigation actions, recycled refrigerants, refrigerant concentration limit, refrigeration detection system, refrigerant detector, releasable refrigerant charge, safety shut-off valve, system refrigerant charge, and ventilated enclosure.
- Clause 4 has been modified to integrate ASHRAE 34 tables and procedures, update A2L references, update requirements for flammable refrigerants in public hallways, and provide new A2L requirements for human comfort.
- Clause 5 has been revised to provide new exemptions from the exemption in Clause 5.2, marking and labelling requirements in Clause 5.11, the addition of references to IIAR, new requirements for secondary coolant systems, and new requirements to address stress corrosion cracking.
- Clause 6 has updated requirements for the use of A2L group refrigerants in mechanical rooms.
- Clause 7 has updated restrictions on rooftop access, and updated references regarding overpressure protection.
- Clause 8 has a new clause 8.4.1 on asset management planning, and new references to ASHRAE 180 to remain in alignment with the B52 Handbook.
- Clause 9 has been updated with a new clause 9.3 for decommissioning.
- Annex J has been updated with new provisions for dry ice formation.
- Table L.1 has been removed from Annex L
- A new Annex M for frequently used refrigerants has been introduced.
- A new Annex N provides requirements for effective dispersal volume calculations.
- A new Annex O provides requirements for releasable refrigerant charge calculations.
- A new Annex P provides refrigerant detection system requirements.
- A new Annex Q provides requirements for mechanical ventilation for refrigerant safety mitigation.
The code was released on June 5, with the review period ending on Aug. 5.
This is the thirteenth edition of B52, Mechanical refrigeration code. The latest published edition was in 2018 and applied to all refrigeration systems installed, whether in new or existing buildings, to systems that undergo substitution of refrigerant, and to parts that are replaced in or added to the system.
The standard doesn’t have the force of law until officially adopted by a jurisdiction.