Computer Room Efficiency

Measure Description

The Statewide CASE Team investigated several code change opportunities improve energy performance of computer room mechanical and electrical systems. After initial research, including interviews with stakeholders, the Statewide CASE Team determined that the submeasures below did not meet the Energy Commission’s requirements for market readiness, technical feasibility, cost-effectiveness, or enforceability at the time they were considered. The data center efficiency submeasures that are included in the 2022 Code Cycle can be seen here: Nonresidential Data Center Efficiency.

Server Utilization Monitoring

Non-utilized servers use power 24 hours per day, seven days per week without doing useful work, resulting in energy waste. Without server utilization monitoring, it is nearly impossible to know whether or not a server is being used. Server utilization monitoring lets computer room operators know which servers are not being utilized and are therefore candidates for energy savings measures such as server virtualization or decommissioning. Server utilization monitoring systems monitor certain server characteristics, including central processing unit utilization, memory utilization, disc input/output, etc. Studies indicate the quantity of non-utilized servers in computer rooms often can be 20-30 percent, with many of these servers not having delivered information or computing services in six months or more. While server utilization monitoring is common among larger enterprise data centers, server utilization monitoring is less common in small and medium computer rooms.

The Statewide CASE Team decided to stop pursuing server utilization monitoring for the 2022 code cycle for two reasons:

1. Server utilization monitoring software and the servers on which it is installed are typically installed in the building after a certificate of occupancy permit is issued. This poses a significant regulatory hurdle for which the Statewide CASE Team does not have a viable solution at this time.
2. Most server utilization monitoring software requires a monthly service subscription. Analysis is not currently showing this measure to be cost effective based on energy savings over the life of the measure.

Generator Crankcase Heating

Generator crankcases must be kept warm at all times, typically around 110°F, which is commonly done with a generator-mounted electric resistance heater.  There are several options for reducing crankcase heater energy. One approach is to locate the generator in an enclosed, insulated space to reduce the heat loss from the generator to the outdoors and reduce the runtime of the heater. Other energy savings approaches involve more efficient heating sources, including transferring warm computer room relief air into the generator room or using heat pumps for heating.

The Statewide CASE Team investigated code change opportunities to incorporate efficient generator crankcase heating requirements for the 2022 code cycle. After initial research the Statewide CASE Team decided to discontinue pursuit of this submeasure for the 2022 code cycle in an effort to focus on more cost effective measures.

Liquid Cooling Credit in Compliance Software

Using liquid cooling instead of air-cooled server cooling saves energy by eliminating mechanical supply fan energy and server fan energy. While this is a technology that is decades old, it is not common practice for most computer rooms.

The Statewide CASE Team investigated adding a compliance software credit for installing liquid cooling in computer rooms for the 2022 code cycle. Since this would not involve a code change requirement, the Statewide CASE Team decided to consider pursuing this submeasure outside of the CASE Report process.

Relevant Documents

• Data Center Efficiency Submeasure Summary
• Presentation – Oct. 15 – Nonresidential HVAC Part 1 Utility-Sponsored Stakeholder Meeting
• Notes – Oct. 15 – Nonresidential HVAC Part 1 Utility-Sponsored Stakeholder Meeting