This is an easy prerequisite to meet, since installing equipment without CFC-based refrigerants is now standard practice in new construction. Nearly all industrialized nations have signed the Montreal Protocol, which called for a complete phase out of CFC-based refrigerants by 1995, and HCFCs by 2030 in developed countries. As a result, compliant, environmentally preferable refrigerants that comply with this prerequisite are the only option available for new systems. 

Existing CFC-based equipment must be phased out

If existing equipment or a district chilled water system is being used, it must be CFC-free—or you (or the owner of the system) must commit to phasing out CFC refrigerants through refrigerant conversion or equipment replacement within five years of “substantial completion” of your project. In either case, the annual leakage rate of CFC-based refrigerants must be reduced to 5% or less.

If the owner of the district cooling system is unwilling to conduct a phase-out, while the economic analysis suggests that it should, in fact, be done, your project could forfeit LEED certification. In this case, you could install your own cooling system to achieve the prerequisite.

Generally, equipment replacement is economically feasible because older systems are far less efficient than newer ones. However, an exemption can be granted if a third-party analysis shows that the replacement or conversion of the system is not economically feasible by nature of having a simple payback greater than ten years.