UPGRADES FOR ENERGY EFFICIENCY Vali Sorell, PE Vice President National CF Chief HVAC Engineer Syska Hennessy Group AFCOM NC Chapter, November 12, 2014

Agenda – Non-Capital Upgrades Improvements in Air Flow Improvements in Setpoints Improvements in IT Operations – Capital Upgrades CRAH Unit Upgrades Economizers New Build Improvements – Reduction of Impact to Utilities Importance of Reducing kW Demand 2Syska Hennessy Group / Upgrades for Energy Efficiency

Agenda – Non-Capital Upgrades Improvements in Air Flow Improvements in Setpoints Improvements in IT Operations – Capital Upgrades CRAH Unit Upgrades Economizers New Build Improvements – Reduction of Impact to Utilities Importance of Reducing kW Demand 3Syska Hennessy Group / Upgrades for Energy Efficiency

Improvements in Air Flow – Biggest mistake owners make is not managing air flow This leads to orphaned capacity Which leads to wasted energy – To manage air flow, must MIND THE GAP! Minimize “recirculation” and “bypass” (or use containment) Monitor load per cold aisle Adjust air flow per cold aisle for the load in that cold aisle 4Syska Hennessy Group / Upgrades for Energy Efficiency

Improvements in Air Flow 5Syska Hennessy Group / Upgrades for Energy Efficiency Not so good… Much better!

Improvements in Air Flow – Don’t forget to look in the less obvious places! – These blatant gaps can rob 25% - 50% of actual cooling capacity! 6Syska Hennessy Group / Upgrades for Energy Efficiency

Improvements in Air Flow 7Syska Hennessy Group / Upgrades for Energy Efficiency Both of these lead to orphaned capacity

Improvements in Air Flow – Do not install tiles where they are not needed – When CRACs/ CRAHs can modulate, they should adjust based on the amount of tiles installed 8Syska Hennessy Group / Upgrades for Energy Efficiency

Agenda – Non-Capital Upgrades Improvements in Air Flow Improvements in Setpoints Improvements in IT Operations – Capital Upgrades CRAH Unit Upgrades Economizers New Build Improvements – Reduction of Impact to Utilities Importance of Reducing kW Demand 9Syska Hennessy Group / Upgrades for Energy Efficiency

Improvements in Setpoints 10Syska Hennessy Group / Upgrades for Energy Efficiency

Improvements in Setpoints – Use the thermal envelope – Use the highest temperature possible – THIS SINGLE DESIGN DECISION MAKES THE BIGGEST IMPACT ON ENERGY 11Syska Hennessy Group / Upgrades for Energy Efficiency

Improvements in Setpoints – The reason users use 65 deg F in the cold aisle rather than 80 deg F: Fear that high points in the cabinets will overheat – Follow the best practices and this stratification will not occur – How much difference is there between these two setpoints? 12Syska Hennessy Group / Upgrades for Energy Efficiency

Improvements in Setpoints – When staying within “Recommended Range” 13Syska Hennessy Group / Upgrades for Energy Efficiency At 65 deg F SAT (Charlotte) At 80 deg F SAT (Charlotte)

Improvements in Setpoints – With excursions into “Allowable Range” 14Syska Hennessy Group / Upgrades for Energy Efficiency At 65 deg F SAT (Charlotte) At 80 deg F SAT (Charlotte) Up to 90 deg F SAT (Charlotte)

Agenda – Non-Capital Upgrades Improvements in Air Flow Improvements in Setpoints Improvements in IT Operations – Capital Upgrades CRAH Unit Upgrades Economizers New Build Improvements – Reduction of Impact to Utilities Importance of Reducing kW Demand 15Syska Hennessy Group / Upgrades for Energy Efficiency

Improvements in IT Operations – Too often, design decisions are made to minimize PUE – only to be overridden when the owner sees how much the facility will cost. – PUE is a BAD metric to use for design decision making. PUE = annual energy into facility / annual energy consumed by IT equipment PUE does not address IT energy It is not a good decision-making tool in selecting the most suitable design It does not include use of other resources, such as – KW demand (yes, this is a resource separate from energy) – gallons of water – Therms of gas 16Syska Hennessy Group / Upgrades for Energy Efficiency

Improvements in IT Operations 17Syska Hennessy Group / Upgrades for Energy Efficiency 131 million kWH/year 105 million kWH/year 110 million kWH/year

Improvements in IT Operations – It is important to consider: More efficient servers Refresh when new technologies are available Virtualize Consider use of Cloud Computing Remove unused (comatose) servers New technologies – Liquid immersion cooling – Air-Liquid hybrid cooling – Scope of potential IT energy savings is greater than the entire infrastructure energy 18Syska Hennessy Group / Upgrades for Energy Efficiency

Agenda – Non-Capital Upgrades Improvements in Air Flow Improvements in Setpoints Improvements in IT Operations – Capital Upgrades CRAH Unit Upgrades Economizers New Build Improvements – Reduction of Impact to Utilities Importance of Reducing kW Demand 19Syska Hennessy Group / Upgrades for Energy Efficiency

CRAH Unit Upgrades – For DCs with old CRAC units: Upgrade to CRAH units, if feasible Energy supporting CRAC units is ~2X energy for CRAH (chilled water) units If conversion to chiller water is not feasible, consider pumped refrigerant units – For DCs with old CRAH units: Upgrade to VFD – Modify controls sequences to reduce speed to just meet the load – System performance is improved and operation is more stable – Can be added to existing CRAHs Upgrade to ECM (electronically commutated motors) – Similar in concept to VFD control, but slightly more efficient – Requires more upgrades – Can easily be rolled into economizer upgrade 20Syska Hennessy Group / Upgrades for Energy Efficiency

Agenda – Non-Capital Upgrades Improvements in Air Flow Improvements in Setpoints Improvements in IT Operations – Capital Upgrades CRAH Unit Upgrades Economizers New Build Improvements – Reduction of Impact to Utilities Importance of Reducing kW Demand 21Syska Hennessy Group / Upgrades for Energy Efficiency

Economizers – Airside Uses outside air to cool the data hall Usually implements direct evaporative coolers to cool when hot and dry / humidify when cold Very efficient Requires significant space and cost If high SAT is selected, and/or if no cooling is required, this option is very attractive – Waterside Uses cooling tower water to provide cooling when outdoor wet bulb temperature is low Not as efficient as Airside, but extremely cost effective when coupled with existing CRAH units No extra humidification and filtration required This option usually has the best TCO due to low capital expense – Indirect Evaporative Coolers Outside air is cooled by evaporating water into it; this outside air then to cools the air for the data hall air through a heat exchanger Very efficient Requires significant space and cost No extra humidification and filtration required This options usually has the highest TCO unless the design outdoor is dry. Under those conditions, the plant size can be reduced, making the TCO more favorable 22Syska Hennessy Group / Upgrades for Energy Efficiency

Economizers – All buildings are required to incorporate an economizer (ASHRAE 90.1) – The selection of the type of economizer is not a straightforward decision; TCO, convenience, and risk become major considerations – Very dependent on cost of energy and hours of available free cooling – Hours of available free cooling is very dependent on the selection of supply air temperature 23Syska Hennessy Group / Upgrades for Energy Efficiency

Economizers – But is there risk to the critical load when using an economizer? – Risk can be mitigated by: Proper controls and sequencing of valves, motors, and other equipment Commissioning Increasing the hours of available free cooling! – Consider this: The fewer the hours required of the mechanical plant (the least reliable portion of the infrastructure), the more reliable becomes the operation of the infrastructure 24Syska Hennessy Group / Upgrades for Energy Efficiency

Agenda – Non-Capital Upgrades Improvements in Air Flow Improvements in Setpoints Improvements in IT Operations – Capital Upgrades CRAH Unit Upgrades Economizers New Build Improvements – Reduction of Impact to Utilities Importance of Reducing kW Demand 25Syska Hennessy Group / Upgrades for Energy Efficiency

New Build Improvements – A facility starting from scratch will look very different from one that is upgraded over its life – Accommodations can be made to incorporate a more energy efficient design right from the start. This may include: Extra yard space – E.g. dry coolers may be required if liquid cooling is used Extra fan gallery or air handling unit gallery space – E.g. indirect evaporative coolers may require twice the space compared to conventional air handlers Roof penetrations for rooftop equipment – E.g. indirect evaporative coolers are well suited for rooftop installation Wall penetrations for outside air and exhaust air – E.g. airside economizers require wall space or roof space for intake/exhaust 26Syska Hennessy Group / Upgrades for Energy Efficiency

New Build Improvements – New technologies can be incorporated at the design phase Liquid immersion cooling (which may change the look and feel of the data hall) – Can eliminate mechanical cooling – High temperature cooling (this is not an oxymoron!) opens the possibility of heat reclaim Elimination of cooling – Today’s servers are designed for higher inlet temperatures (>90 deg F) and lower air flow (i.e. higher delta T) – Simply ventilating the data hall should be sufficient – If a data hall is ventilated only (no cooling, no humidification) the ideal infrastructure efficiency would be achieved. Only fan energy would be utilized. 27Syska Hennessy Group / Upgrades for Energy Efficiency

Agenda – Non-Capital Upgrades Improvements in Air Flow Improvements in Setpoints Improvements in IT Operations – Capital Upgrades CRAH Unit Upgrades Economizers New Build Improvements – Reduction of Impact to Utilities Importance of Reducing kW Demand 28Syska Hennessy Group / Upgrades for Energy Efficiency

The Importance of Reducing kW Demand – Most data center metrics focus on energy PUE is an energy term TCO analyses look at $’s in the life of the facility, which is proportional to the energy use (it also includes capital costs and other owning costs) USGBC’s LEED energy modeling requirement looks at operating cost/year, which is a surrogate for energy use 29Syska Hennessy Group / Upgrades for Energy Efficiency

The Importance of Reducing kW Demand – How does kW Demand fit in? End users have expectation of availability of full capacity from the grid, even if it’s a transient need for a few hours in the year When that capacity cannot be met, rolling brownouts and blackouts begin This is bad for business and troublesome for the end user with a need for continuous uptime Deficiencies are usually met by running generating capacity, and risk is increased proportionately 30Syska Hennessy Group / Upgrades for Energy Efficiency

The Importance of Reducing kW Demand – There is a general misconception about the need to save energy: It’s not just about energy; saving on demand may have a bigger role! – The EPA/DOE/US-State-Local Governments have an interest in conserving energy – The end user has an interest in conserving energy (actually, the end user wants to save $$) – The utility that sells the energy to the end user has an interest in NOT building new generating capacity or NOT running peaking plants » Building new capacity is extremely expensive, complex, and time consuming » Running peaking plants to meet the occasional demand is not cost effective to the utilities 31Syska Hennessy Group / Upgrades for Energy Efficiency

The Importance of Reducing kW Demand – The end user has several options: Load curtailment/demand response – i.e. reduce load during high demand peaks – In exchange, utility gives reduced rates to the end users – This may require running generators – this may be risky and may violate state and local ordinances for air quality Load shedding – i.e. design a cooling system with extended thermal storage (beyond what a typical data center would need) – The capital expenses for this type of system usually exceed other options – The controls for load shedding are complicated – Increased risk of failure – e.g. one event when load shedding doesn’t work may negate cost savings for month or year – Will use more energy – Not recommended for critical facilities 32Syska Hennessy Group / Upgrades for Energy Efficiency

The Importance of Reducing kW Demand – For cooling technologies, some options that reduce the peak demand: DX CRAC units/remote condensers Chilled water CRAH units with air-cooled chillers Chilled water CRAH units with water-cooled chillers Built-up air handling units with water-cooled chillers Indirect evaporative coolers with DX coils/remote condensers (but only if a credit for reduced cooling capacity is taken) Immersion liquid-cooling Ventilated-only spaces 33Syska Hennessy Group / Upgrades for Energy Efficiency BETTER WORSE

The Importance of Reducing kW Demand – Economizers DO NOT affect the peak demand But utilities will incentivize for better economizers to save energy – The utilities will also incentivize to reduce the annual peak demand through innovative technologies This usually provides the bigger bang for the buck, for the reasons already stated The incentive programs are often published and socialized to the many end users that would need them, but there are cases where this program can be negotiated 34Syska Hennessy Group / Upgrades for Energy Efficiency

Parting thoughts… – Reduction of ITE kW demand is the biggest piece of the energy AND demand pie – End users must consider how to reduce IT energy/demand, and how to quantify this reduction (through virtualization, improved IT equipment selection/design, equipment refresh, etc.) so that its value, in terms of incentives and rebates, can be calculated. 35Syska Hennessy Group / Upgrades for Energy Efficiency

Questions, comments, thoughts, complaints ??? 36Syska Hennessy Group / Upgrades for Energy Efficiency Vali Sorell, PE Syska Hennessy Group 201 S. Tryon St., Suite 1400 Charlotte, NC