I am working on a data center which is located in climatic zone 4A. considering the size of computer rooms in this development, System type 11 should be used in computer rooms.
Based on section G3.1.2.6.1 fluid integrated economizer should be included into system now I have two questions:
- Does it mean that there is no need for air economizer and only water economizer should be included?
- If the software that I use does not able to include water economizer, is it possible to include this in COP calculations of chillers?
Thanks
Tyler Thumma
7GroupLEEDuser Expert
67 thumbs up
July 15, 2021 - 12:50 pm
1. No, as this would meet G3.1.2.6 exception 3.
2. You would need to provide supporting calculations as to how the COP was adjusted to account for the water economizer operation. A better approach would be to perform an exceptional calculation using hourly simulation data to determine the savings associated with the water economizer in the Baseline model.
Narguess Kh
August 3, 2021 - 11:25 am
Thanks Tyler for your respons
Regarding water economizer, do you suggest to use dynamic thermal model to calculate the load only and then use excel to adjust the COP based on external temperature?
Tyler Thumma
7GroupLEEDuser Expert
67 thumbs up
August 3, 2021 - 11:53 am
Yes, that is one option but as I mentioned above I think the best approach would be to use excel to determine when the economizer would be enabled and the corresponding savings when the cooling load can be met through the economizer.
Narguess Kh
August 3, 2021 - 12:03 pm
Thank you for your response.
The project I work on is a big data centre and I need to use System 11 for baseline building, based on Appendix G, an integrated fluid economizer meeting the requirements of Section 6.5.1.2 should be included in the system. For computer rooms Section 6.5.1.2 only suggests that the fluid economizer should be able to provide up to 100% of the expected system cooling load at outdoor air temperatures of DBT: 4.4°C and WBT:1.7 °C. So what you suggest is use excel and assume that if external temperature is equal or less than high limit the system is going to benefit from free cooling and if the outside air temperature is higher than specified temperatures, no free cooling should be included?
Tyler Thumma
7GroupLEEDuser Expert
67 thumbs up
August 3, 2021 - 12:53 pm
The economizer should be able to meet 100% of the cooling load below these temperatures, and as much of the cooling load as possible above these temperatures. They should not be considered to be a high-limit shutoff like the air-side economizer.