We have a hospital project using varable water cooled screw chiller with the minimum COP of 5.9 which is defined as per Path B ASHRAE 90.1 2013
Now as per ASHRAE 90.1 2013, we have to follow Path A for chiller efficiency in basecase where COP comes around 6.11.
So, the proposed case chiller COP(5.9) is less than basecase chiller COP(6.11). Am i making any mistake in selecting the baseline path?
Thanks in advance.
Tyler Thumma
7GroupLEEDuser Expert
67 thumbs up
February 21, 2025 - 11:04 am
This is correct. Make sure the part-load efficiencies are accounted for as well because Path A has better full-load efficiencies but lower part-load efficiencies (IPLV) than Path B.
Jamy Bacchus
Associate PrincipalME Engineers
28 thumbs up
February 21, 2025 - 11:41 am
Anurag,
Why are you using 90.1-2013 for v4.1 project?
Anurag Ghosh
February 22, 2025 - 8:17 am
Hi Jamy,
The project follows an Indian rating system and expects to follow ASHRAE 90.1 2013. Since this forum also deals with ASHRAE 90.1 related queries, I believed it the right place to ask this question. I apologize for any confusion.
Jamy Bacchus
Associate PrincipalME Engineers
28 thumbs up
February 22, 2025 - 3:18 pm
Hi Anurag,
The LEEDuser forums are grouped by rating system and credit. So if you're using LEED rating system which isn't a USGBC version listed, then you should clarify that in your queries so that we're not crowdsourcing a response which is relevant to a USGBC credit or prereq.
There are a few nuances here: v4 references ASHRAE Standard 90.1-2010 and allows 90.1-2013 to be used in jurisdictions where that's been adopted. LEED v4.1 references 90.1-2016. So your queries on things related to ASHRAE 90.1 and LEED should probably be sorted into those buckets. Here's why that's important: 90.1's Appendix G underwent a complete overhaul in the 2016 version, which changed the methodology for the baseline's creation.
Anurag Ghosh
February 26, 2025 - 10:41 am
Hi Jamy, I completely understand and appreciate you raised this point. I will be careful next time in putting my questions into above buckets. And thanks for the clarification.
Anurag Ghosh
March 1, 2025 - 10:43 pm
Hi Tyler and Jamy,
Can you suggest whether path A or path B chiller efficiency to be chosen for ASHRAE 90.1 2010 PRM baseline case. It does not specifically mentions about any path unlike path A exclusively mentioned in ASHRAE 90.1 2013/2016?
Thanks in advance.
Tyler Thumma
7GroupLEEDuser Expert
67 thumbs up
March 3, 2025 - 7:50 am
Path A should be used in ASHRAE 90.1-2010 as well.