Help with Interpretation!

Hey Daniel, Thanks so much for the response! I appreciate your take on the credit interpretation and will err on the side of caution as well and advise the building owner (whose equipment is 20 yrs old) to develop a CFC phase out program. If you hear anything definitively from the USGBC regarding and official ruling - please pass it on. I will do the same. Thanks again.

Where in any LEED Reference Guide and/or addenda is there discussion of the payback period? I cannot find any reference to a 10-year payback being the defining timeline for exemption from this prerequisite exept for the discussion of this credit here on LEEDuser.

I will double-check on this, but the 10-year period is specified in the LEED-EBOM EAp3 credit language. Even though this isn't specified in LEED-CI, with the alignment process that took place for LEED 2009, this kind of definition typically carries across LEED rating systems.

Tristan: Thank you so much for checking into that...it's confusing enough without having to consider cross-pollination of rating systems! Daniel: some additional thoughts I have on the confusion of existing HVAC&R equipment which use CFC-based refrigerants: The root cause of the confusion, as noted by Robin above, seems to lie on page 148 of the LEED ID+C Reference Guide under heading 4. Implementation, which reads: “Use only non-CFC-based refrigerants in all base building HVAC&R equipment built for the project; only HVAC systems built for the project are within the scope of work.” I humbly believe that the last clause in this sentence refers to NEW equipment. NEW equipment which serves the tenant space must use non-CFC based refrigerants. For clarity, it might have been better had this read "the scope of work includes only (NEW) HVAC systems built for the project AND any existing HVAC&R equipment which serves the tenant space must phase-out CFC-based refrigerants or otherwise demonstrate that it is not economically feasible to do so". District Energy Systems would still follow the technical guidance as referenced on page 149) To support the contention that the credit intent is to address existing building HVAC&R equipment that serves the CI tenant, read on the same page 148 the discussions under Economic Issues: “…existing buildings may have CFC-based refrigeration equipment. Energy, demand, and maintenance systems, If savings offset costs, a CFC phase-out plan must be implemented to earn this prerequisite. If savings do not offset costs, detailed calculations and the results of a qualified third-party audit must confirm that CFC conversion or replacement is economically infeasible.” Similarly, read the discussion on page 149 under 5. Timeline and Team: “Consult with a mechanical engineer or HVAC&R specialist to confirm the presence of CFC-based refrigerants in the base building HVAC&R systems, If CFC-based refrigerants are located, the building owner should develop a phase-out plan and convert to less environmentally harmful refrigerants. Do not install any systems with CFC-based refrigerants." Lastly, read the statements under 6. Calculations: “There are no calculations associated with this prerequisite unless a third-party economic audit is conducted to determine feasibility of retrofitting existing equipment”. It seems to me that this credit intent is very clear that new equipment must not use any CFC-based refrigerants and that existing equipment THAT SERVES THE TENANT SPACE that contains CFC-refrigerants must be shown by a third party analysis to be economically feasible (in which a phase-out plan is required) or not economically feasible (in which case there may be an exemption to this prerequisite). I also believe that existing HVAC&R equipment that might contain CFC-based refrigerants that do NOT serve the tenant space would NOT be in the scope of this prerequisite. (If the building Owner could be persuaded to change ALL equipment that was not compliant but which did not serve the tenant space in question, might this be a possible ID credit opportunity since it would fall without the LEED boundary/scope of work?) That one sentence on page 148 causes so much confusion when everything else seems very clear.

I would like to point out here that the 'Implementation' section in the Reference Guide is generally an explanation of the credit suggesting possible strategies of complying with it. It is not the same as the 'Requirements' of a credit. The base building systems are called out for best practice and recommend an audit. As state above, the base building systems and those serving other tenants are not subject to the credit requirements.