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NC-v4.1 EAp2:Minimum Energy Performance

Submitting ASHRAE 90.1-2019 model in lieu of 2016 - LI 10500

Brightworks Sustainability

Brightworks Sustainability LLC

LEEDuser Premium Member

36 thumbs up

Project location :

U.S. and Canada

August 15, 2022

Good afternoon,

We’re working with a Multifamily building that’s pursuing compliance with LEED V4.1. According to LI 10500 a project may apply ASHRAE 90.1-2019 Appendix G in lieu of ASHRAE 90.1-2016 Appendix G. There are some key differences we identified between both ASHRAE versions. Will these be the correct assumptions to consider within our 2019 model (which is pursuing 2018 Seattle Energy Code compliance):

DHW demand: Baseline values shall not follow EPACT 1992 water demand. The baseline hot water demand should be based on the maximum allowed by the applicable code. In our case, the project is in Seattle and code maximum flow rates are 1.8gpm for showerheads and 1.2gmp for sinks. Should these values be the ones modeled in the Baseline (1.8gpm and 1.2gpm)?
Envelope air leakage: Baseline design shall be modeled using 1.0 cfm/ft2. Meanwhile proposed design shall be modeled with 0.60cfm/ft2 if prescriptive barrier requirements are met.
In-unit LPD: Proposed design 0.60W/ft2 or as designed, whichever is greater. Baseline: 1.07W/ft2.

Thanks!

Post a reply

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Wed, 08/17/2022 - 15:40

DHW Demand - I would use the baseline allowance from the Indoor Water Use Reduction prerequisite. Air Leakage - correct LPD - correct

Brightworks Sustainability

Brightworks Sustainability LLC

LEEDuser Premium Member

36 thumbs up

Thu, 08/18/2022 - 18:47

Thanks! We'll base the DHW Demand using baseline allowance from the LEED Indoor Water Use Reduction prerequisite. An additional question related to receptacle equipment: can elevator energy savings be claimed with the ASHRAE 90.1-2019 Baseline model?

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Fri, 08/19/2022 - 17:39

It appears that 90.1-2019 does define some baseline parameters for elevators. So yes you should be able to claim energy savings, I think without an exceptional calculation.

LEEDuser Basic Member

3 thumbs up

Thu, 12/01/2022 - 17:53

where is the DHW demand allowance found in the Water Use Reduction prereq?

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Mon, 12/05/2022 - 21:10

It isn't. You calculate it based on the baseline flow rates for the Water Use Reduction prereque. You then do the same for the proposed model using the flow rates in the building design. This should generate a different DHW demand and show a savings.