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!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
August 17, 2022 - 11:40 am
DHW Demand - I would use the baseline allowance from the Indoor Water Use Reduction prerequisite.
Air Leakage - correct
LPD - correct
Brightworks Sustainability
Brightworks Sustainability LLC47 thumbs up
August 18, 2022 - 2:47 pm
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 Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
August 19, 2022 - 1:39 pm
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.
3 thumbs up
December 1, 2022 - 12:53 pm
where is the DHW demand allowance found in the Water Use Reduction prereq?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
December 5, 2022 - 4:10 pm
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.