# Presentation: 526696

## The Late Night Top 10 -Energy Saving Measures for your Data Center

## Energy Efficiency in Data centers

-  LBNL benchmarking and case studies
-  California Energy Commission
-  Pacific Gas & Electric Company
-  NYSERDA
-  DOE
-  DOE energy assessments
-  EPA report to Congress
-  Resources
-  Letterman Top 10 opportunities

## Benchmarking energy end use

## Data Center Research Roadmap

***Data Center Research Roadmap***

## IT equipment load intensity

## Overall power use in Data Centers

- Courtesy of Michael Patterson, Intel Corporation

## Data Center performance differences

## Performance varies

- The relative percentages of the energy actually doing computing varied considerably.

## IT equipment percentage to total

**Ave. 0.49**

- Higher is better

## HVAC system effectiveness

- We observed a wide variation in HVAC performance

## Benchmarking leads to best practices

- 	The ratio of IT equipment power to the total is an indicator of relative overall efficiency.
- 	Examination of individual systems and components in the centers that performed well helped to identify best practices.

## Best practice topics

## Design guidelines for 10 “Best Practices” were developed in collaboration with PG&E 

- Guides available through PG&E’s Energy Design Resources Website

## Design guidance

- A web-based training resource is available

- http://hightech.lbl.gov/dctraining/TOP.html

## Late night top 10 opportunities

- 	Staying up late worrying about your data center’s energy use?
- 	Lets see what David Letterman would come up with.

## Number 10:

**Efficient Lighting/ Lighting Controls**
** **
- Lighting represents a small % of power use in a data center
- Lights are typically on 24x7
- Staff is rarely present in data centers

-   Reducing lighting intensity also 	saves HVAC energy
-   Lighting controls are well proven

## punch line

**Computers don’t need lights!**

## Number 9:  	

- Data center systems operate 24x7
- Premium efficiency motors can save several % over less efficient models
- Newer motors are even more efficient than premium motors of several years ago

***Use Premium Efficiency Motors***

## Check motor efficiency

- MotorMaster is a good resource

## Punch line

**A penny saved is a penny earned!**

## Number 8

- Power and flow related by cube law
- Small reductions in flow result in large energy savings
- No data center needs full capability all the time
- Operating multiple fans or pumps at slower speeds is often a good strategy

*** ******Variable Speed Everything***

## punch line		

**Thank you cube law!**

## Number 7

- Chiller efficiency dominates but pumps, fans, system effects contribute
- kW/ton

***Efficient chilled water plant***

## punch line

**How low can you go?**

## Number 6

- Many power conversions take place in a data center from end to end
- Each conversion loses some power – converted to heat
- Optimizing or eliminating conversions has a short pay back

***Electrical power conversion***

## Data Center power conversions

***Data Center power conversions***

- PDU

## Research into power conversion losses

***Uninterruptible Power Supplies (UPS)***

***Power Supplies in IT equipment***

## punch line

- AC – DC – AC – AC – DC – DC

## Number 5

- Typical servers’ processors are busy 10% or less on average
- Consolidating can eliminate many servers
- Older less efficient equipment can be removed
- Immediate *decrease *in electrical and HVAC load
- Quick pay back

***Virtualization***

## punch line		

**Take your IT person to lunch!**

## Number 4

- Air management – a huge opportunity
- Efficiency of air handlers varies
- W/cfm a key metric
- ΔT is also a key metric
- Avoid mixing of cold and hot airstreams
- Eliminate simultaneous humidification/dehumidification

***Air side efficiency***

## Fan energy savings – 75%

**If there is no mixing of cold supply air with hot return air -**
**fan speed can be reduced**

## punch line

- 	**Just like oil and water, air shouldn’t be mixed**

## Number 3

- In many climates, compressor-less or reduced use of compressors is possible for much of the year
- Air economizers are feared because of contamination or loss of humidity control
- Some jurisdictions are requiring air economizers in data centers
- Water side economizers (heat exchange with cooling tower) is a good option

***Free cooling***

## Air economizer study

- Eight centers were monitored with particle counters
- Three were successfully using air economizers
- Measurements taken inside and outside the centers
- Humidity was monitored

## Air Quality Guidelines

- Limited literature connecting pollutants to equipment failure
- ASHRAE
- Design Considerations for Data/Com Equipment Centers
- Guidelines for particles, gases, humidity
- Industry Sources: Telcordia GR-63-CORE/IEC 60721-3-3
- Designed for telephone switching centers
- Based on research over 20 years old
- Primary concern: current leakage caused by particle bridging – hydroscopic salts in combination with high humidity

**Notes:**
Currently I’m interested in testing that belief on data centers:
These are buildings house rows and rows of servers

Common in California
Growing
Because of all the heat for the servers, lots of energy to cool equipment

Use lots of energy, so have a pretty big environmental impact...

So what’s the air quality connections here?

## Contamination limits

**IBM Standard**

**EPA 24-Hour Health Standard**

**EPA Annual Health Standard and ASHRAE Standard**

## Outdoor measurements

***Outdoor measurements***

**IBM Standard**

**EPA Annual Health Standard**

**EPA 24-Hour Health Standard**

***and***** ASHRAE Standard**

## Indoor measurements

***Indoor measurements***

**IBM Standard**

**EPA Annual Health Standard**

**EPA 24-Hour Health Standard**

***and***** ASHRAE Standard**

## Indoor measurements

***Indoor measurements***

## Data center w/economizer

***Data center w/economizer***

## Humidity measurements

***Humidity measurements***

**ASHRAE Recommended Upper Limit**

**ASHRAE Recommended Lower Limit**

**ASHRAE Allowable Lower Limit**

**ASHRAE Allowable Upper Limit**

## Findings

- High concentration of water soluble salts in combination with high humidity can cause failures
- ASHRAE guidance is drastically lower than one manufacturer’s standard
- Particle concentration in data centers is typically  an order of magnitude lower than ASHRAE limits
- Economizer use can increase particle concentration to ASHRAE limits
- A modest improvement in filtration would provide equal conditions to centers not using economizers
- Humidity control is easily attainable

## Punch line

**What part of free is not appealing?**

## Number 2

- ASHRAE Thermal Guidelines define conditions at the inlet to the IT equipment
- Often, operating temperatures are much less than recommended
- Often humidity is more tightly controlled than recommended

***Environmental****** ******conditions***

## Temperature guidelines – at the inlet to IT equipment

- ASHRAE Allowable Maximum

- ASHRAE Allowable Minimum

- ASHRAE Recommended Maximum

- ASHRAE Recommended Minimum

## Humidity guidelines – at the inlet to IT equipment

- ASHRAE Allowable Maximum

- ASHRAE Allowable Minimum

- ASHRAE Recommended Maximum

- ASHRAE Recommended Minimum

## Air Isolation Concepts

- Better isolation of hot and cold aisles will improve temperature control and allow air system optimization
- Airflow (fan energy) can be reduced if air is delivered without mixing
- Air system and chilled water systems operate more efficiently at higher temperature differences
- Temperatures in entire center can be raised if mixing is eliminated.  It may be possible to cool with tower water rather than use of chillers.

## Isolation scheme – cold aisle isolation

## Isolation scheme – hot aisle isolation

## Better temperature control allows raising the temperature in the entire data center

- ASHRAE Recommended Range

- Ranges with aisles isolated

## Punch line

**It’s not nice to fool Mother Nature**
**(think about it)**

## Number 1	

**Liquid Cooling**

-   Rising heat intensity will lead to liquid cooling
-   Water can hold approximately 3500 times the 	amount of heat that air can hold
- Liquid cooling is already taking many forms
-  Rack level solutions
-  Chip level solutions
-  Building level solutions

## Moving to liquid cooling

-  Hybrid solutions as an interim step
-  Integrating liquid solutions all the way out of the building
-   Liquid doesn’t have to mean water
-  35-50% reduction in HVAC energy is possible by going liquid

## Punch Line

**Sometimes it pays to be all wet!**

## Recapping the Top 10

**10 ****	****Lighting controls**
**9 ****	****	****Premium efficiency motors**
**8 ****	****	****Variable speed everything**
**7 ****	****	****Efficient chilled water plant****	****	**
**6 ****	****	****Power conversion efficiency****	****	**
**5 ****	****	****Virtualization**
**4 ****	****	****Air side efficiency****	****	**
**3 ****	****	****Free cooling**
**2 ****	****	****Appropriate environmental conditions**
**1****	****	****Liquid cooling**

## Conclusion	

**Thank you..... Questions?**