Last chance to comment on LEED v5

Enhanced Refrigerant Management Why is the GWP benchmark for  HP Service Water Heaters so high (1400), especially compared to the HVAC one?  There are already multiple CO2 based HP water heaters on the market that would have a GWP of 1 and the rest will be using R-32 or R-454b, most likely.  There needs to be room to show the reduction to achieve the points, but 1400 seems high.

ASHRAE Proposed Revision to Option 4 (Peak Thermal Load Reductions) Path 1 (Peak Load Intensity) Substitute current language as follows: Limit the sum of peak heating load and peak cooling load per unit of treated floor area to be less than or equal to the thresholds specified in Table 2 below. Calculate peak loads using a methodology as prescribed in ANSI/ASHRAE/ACCA Standard 183 Peak Cooling and Heating Load Calculations in Buildings Except Low-Rise Residential Buildings which sets minimum requirements for methods and procedures used to perform peak cooling and heating load calculations for buildings except low-rise residential buildings. Reasons for the suggested language modification:

1. ANSI/ASHRAE/ACCA Standard 183 Peak Cooling and Heating Load Calculations in Buildings Except Low-Rise Residential Buildings is recognized as the building industry standard for methods and procedures used to perform peak cooling and heating load calculations for buildings except low-rise residential buildings.
2. USGBC’s position from the Technical Manual called the ADVANCED ENERGY MODELING FOR LEED has stated that: USGBC does not certify or formally approve simulation software packages for compliance with ASHRAE requirements or for generating an appropriate baseline model." We suggest maintaining the USGBC position to “not certify or formally approve software packages for compliance with ASHRAE requirements...”
3. USGBC references appropriate ASHRAE Standards for LEED’s Credits. Examples include:

• (EA) Energy Simulation Credit - references ASHRAE Standard 90.1
• (EA) Commissioning Credits - references ASHRAE Standard 202
• (EA) Peak Loads Credits (option 4, path 2) - references ASHRAE Standard 90.1
• (EQ) Thermal Environment Credits - references ASHRAE Standard 55
• (EQ) Air Quality Credits - references ASHRAE Standards 62.1, 62.2, 170 and 241
• (EQ) Resilient Spaces Credits - references ASHRAE Standard 241 and Guideline 14

We suggest maintaining the USGBC position to refer to the appropriate industry standard, ANSI/ASHRAE/ACCA Standard 183:

• (EA) Peak Loads Credits (option 4, path 1) - proposed reference to ASHRAE Standard 183

  Please note: ANSI/ASHRAE/ACCA Standard 183 is available for free viewing at https://www.ashrae.org/technical-resources/standards-and-guidelines/read-only-versions-of-ashrae-standards​

Making a BMS a prerequisite may be cost prohibitive for smaller projects.

EA Credit : Enhanced Energy Efficiency , what are the European standards equivalent to the ASHRAE?  

EA Credit : Renewable Energy - Most of the buildings aspiring for Platinum certification in Central European cities and their centres have no option to install and utilize Tier 1 and Tier 2 systems to cover 100% of project site energy use. This will only limit Platinum certification to newly built projects, which in most cases are not influential enough to aim for Platinum, Isn't this counter-productive?

EA Credit : Grid Interactive Option 4. Power Resiliency: Critical Loads should be clearly defined, it is unclear whether loads such as Plug Loads are critical or not, to the continuous operation of the building, which dramatically changes the scope of the credit.

Is an AHU with R-454B acceptable refrigerant type under v4.1? 

Yes, its acceptable. R-454B is the newer version of refrigerant which is more enviornmentally friendly alternative. R-454B has a GWP of 466 (which is significantly lower than GWP of R-410 2088) and has a zero ODP. Begining of 2025 many of our LEED projects are using R-454B and meeting EAc Enahnced Refrigerant Management requirement.