Forum discussion
CS-2009 EAp2: Minimum Energy Performance
Dear Sir/Madam,
Per the revised section 1.4 table, the number of secondary CHW pumps and cooling towers should be one. i do not understand it and not find the corresponding item in ashare 90.1-2007 appendix G.
the number of secondary CHW pumps is same to the desgin case, is not it? the number of cooling towers should be same to the number of chillers?
why should they be one?
Thanks in advance
regards,
tiantian
beijing,china.
LEEDuser is supported by our premium members, not by advertisers.
Go premium forTo post a comment, you need to register for a LEEDuser Basic membership (free) or login to your existing profile.
A portion of our building envelope is historic. Can we exclude it from our model?
For an existing building, do I need to rotate the model?
Our process load is higher than 25%. Do we have to justify that?
Our local code references ASHRAE 90.1-2010. Should I use that for my documentation, or 90.1-2007?
Can mezzanines open to floors below be excluded from the energy model?
How do I provide a zip code for an international location?
For a project outside the U.S., how do I determine the climate zone?
For a project outside the U.S., how do I determine the Target Finder score?
Do hotel rooms need automatic light shut-off control?
How commonly are the 90.1 mandatory compliance forms submitted as part of EAp2/EAc1?
The Section 9 space-by-space method does not include residential space types. What should I use?
Can the Passive House Planning Package (PHPP) be used to energy model for LEED?
Which baseline HVAC system do I use if my building has no heating or air conditioning?
Our project has a diesel backup generator. Should we include it in our energy model?
Can SHGC be higher in the proposed than in the baseline model?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
July 8, 2013 - 10:26 am
It is not the same as the design (proposed) case. There should be just one secondary CHW loop serving the building in the baseline.
G3.1.3.11 does not state that there should be more than one tower. It does so for the pumps and if more than one tower was required we would assume that it would say so.
tiantian zhou
July 9, 2013 - 12:27 am
Dear Marcus,
I really appreciate your reply , but I have trouble to understand you.
G3.1.3.11 does not state that there should be more than one tower
you think it means there should not be more than one tower.
There should be just one secondary CHW loop serving the building in the baseline. it is right. But does it mean that there should be one secondary pump serving the secondary CHW loop?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
July 9, 2013 - 9:40 am
There are many instances in 90.1 and Appendix G where you are not directly told what to do. So if it does not directly tell you what to do, the language must be interpreted. Our interpretation is what I stated in my previous post. Based on the language in the section Table 1.4 our opinion aligns with the guidance provided by GBCI.
So yes one secondary pump serving one secondary pump loop.
G3.1.3.11 states that there should be more than one pump if applicable. If the intention was to have more than one tower our interpretation is that they authors would have said so. To do otherwise would be inconsistent. Nowhere does it state that there should be more than one tower. So a literal interpretation is that you only have one tower no matter how many chillers in the baseline.
One thing to keep in mind - the Appendix G baseline never gets built and does not have to fully function in the physical world. Sometimes folks get hung up on trying to design the baseline system.