Hi All,
Greetings!
I am doing Energy Model for LEED CI Project under V3 2009 Rating System. The project is G+10 typical floors. Our tenant’s office is located at 9th Floor. Tenant’s spaces are conditioned by FCU connected with district cooling plant. Fresh air provided via the separate duct from FAHU.
Tenant level energy simulation has carried out considering Appendix G for project space and rest of the floors/spaces are modelled as a simple box to get an impact as built. Cooling capacities, air flow of FCU, lighting design and fan powers are considered as per the tenant’s design.
Gross Floor Area = 200,000 sq.ft, Conditioned Area = 170,000 sq.ft
Project’s Gross Floor Area = 1,100 sq.ft, Project’s Conditioned Area = 1,000 sq.ft,
Please help me by answering the below question.
1. In Baseline Energy Model, I have considered System 8 – VAV with PFP Boxes. Since the total floor is 10. As per the Table 6.8.1C, the Base case COP is 4.45 because the cooling capacity of project space (not whole building) is only 6 tons. Is this correct?
2. In proposed case, 4.18 COP has considered excluding the 5% thermal distribution loss as per DES Guidance. Is this correct?
3. Proposed pump power is calculated based on the GPM/ton proposed for the project space. Is this correct?
4. From the above, Base case COP is higher than the proposed case and the project is not able to meet the required energy savings 15%. Any advice from your side will be helpful.
SSN Energy Model
Mechanical Engineer5 thumbs up
March 4, 2018 - 2:50 am
Could answer the questions asked above?
Thanks...
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
March 7, 2018 - 5:25 pm
So you should be following this LEED Interpretation guidance - https://www.usgbc.org/content/10412 - and applying the DESv2 as applicable. Used Method 1 or 2 noted in the Interpretation to allocate the energy use to your space. Basically you model the whole building and then allocated a proportional amount of energy use/cost to your project.
1. I would think that the COP should be based on the total building cooling capacity.
2. That looks like the default from the DES.
3. It is proportional based on the results of the whole building model.
4. Why are you using the modeling method for such a small space?
SSN Energy Model
Mechanical Engineer5 thumbs up
March 8, 2018 - 4:26 am
Thank You, Mr.Marcus