Hi,
A data centre project that i am working for is applying for LEED CI. We are planning to work on option 1 - prescriptive approach to meet enhanced energy performance.
We have considered VAV system with CO2 sensor for all private offices, conference rooms and have provided separate zone for solar exposed areas. Also the mechanical system efficiency is considered as per CPG. However the zoning control is provided only for the office areas of the project. Is it mandatory to provide zoning control for unoccupied areas such as server rooms ? Also there is no guidelines given for equipment efficiency for CRAC units in CPG. Am i missing out on anything here..
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5912 thumbs up
February 11, 2013 - 9:10 am
No need for zoning controls in unoccupied spaces. CRAC efficiency in not covered by 90.1-2007. It is covered by 90.1-2010 Table 6.8.1K.
Lavanya Veerappa
MsLEAD Consultancy & Engineering services
7 thumbs up
February 12, 2013 - 1:47 am
Thanks for the reply Marcus. I want to be more clear, the CRAC unit is connected to central plant which has air cooled screw chillers serving only critical load.
Does that mean i will have to meet efficiency of CRAC unit as per ASHRAE 90.1 2010 or will i be through with this credit (prescriptive approach) if i just meet the efficiency of the air cooled chillers as per CPG?
Or should i meet efficiency of both ?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5912 thumbs up
February 12, 2013 - 10:37 am
Just the screw chillers would need to comply.
Lavanya Veerappa
MsLEAD Consultancy & Engineering services
7 thumbs up
February 15, 2013 - 12:57 am
Thats great !! Thanks Marcus.
Cassini Kit
Sustainability Consultant8 thumbs up
February 28, 2013 - 10:50 pm
Hi, I am currently working on a data center project also.
May I know if the CRAC unit contains compressor, that means it should be regarded as a air-cool chiller. Is it true that it has to comply with requirements in ASHRAE 90.1 2007 package-type type AC?
If no, are there any reference published by USGBC that it is not in the scope of LEED-CI 2009 version?
thanks very much.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5912 thumbs up
March 1, 2013 - 1:39 pm
Technically this type of unit is not covered by 90.1-2007 so there is no minimum efficiency it must meet. I would look to 90.1-2010 which includes this type of unit for minimum performance criteria.
Cassini Kit
Sustainability Consultant8 thumbs up
March 7, 2013 - 8:20 pm
Hi Marcus, I just send an email to discuss with some staff in USGBC informally about the case of CRAC units with compressor. Then they refer to some specific technical team to review this case. And I asked if possible to adopt the requirement of CRAC units in ASHRAE 90.1 2010.
However, they answered that since there is no specific requirements in Core performance guide and LEED-CI rating system, it may not be excluded. They only suggest us to submit a CIR to the LEED project review team for their official answer.
But you know if we apply a CIR, LEED review team may need 1-2 months to process and replied us 2 months later. The project schedule is tight that we can't wait for this..
So properly we have to change our design now.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5912 thumbs up
March 8, 2013 - 8:02 am
So they said it can't be excluded but they would not tell you what minimum efficiency you needed to meet?
The least risky, most conservative and right thing to do path would be to make sure your units meet the minimums in 90.1-2010.
Amy Boyce
Manager, LEEDUSGBC
29 thumbs up
March 8, 2013 - 10:05 am
Cassini,
I'm sorry that the team was not able to provide a better answer without a CIR. Since I don't know the details of the project, I will not weigh in on that, but I can tell you that the turn-around time for a project-specific CIR is 3 to 4 weeks. I don't know if that fits within your time frame, but I just wanted to let you know.