How to Make the Most of Your

Computer Room Cooling in 2015

With 2015 plans and goals set, its time to improve both the

effectiveness and efficiency of your computer room cooling.

With 2015 well under way, you’ve got some things to think about for your facility...

Demands continue as high as ever for increased data center efficiency, capacity, and reliability.

Recovering stranded cooling capacity (i.e. reducing bypass airflow) allows for increasing computer room density and or reducing operating cost.

Systems like DCIM and full Containment will continue to be heavily discussed, but first you should consider simple, practical steps that can make a huge difference in your efficiency.

Effectively managing your airflow not only makes your equipment run better, but it also reduces energy usage, which saves money and reduces your carbon footprint. We have found that the average data center could save $32,000 annually by taking some of these simple, easy-to-implement steps.

But First…

Let’s discuss the basics.

What is bypass airflow?

Bypass airflow is any conditioned airflow that does not pass through IT

equipment before returning to a cooling unit.

The most common source of bypass airflow his unsealed cable openings.

To overcome the bypass airflow lost through cable openings, it obviously

requires you to run more fans/cooling units to provide sufficient conditioned

air to IT equipment .

Learn more in our Bypass Airflow White Paper >>

Based on a research study

conducted by Upsite

Technologies of 45 data centers

worldwide, we found that the

average data center has nearly 4

times more rated cooling

capacity than IT load.

The average data center has a cooling capacity

nearly 4 times the IT load!

According to PUE…

As Power Usage Effectiveness (PUE) analysis reveals, the cooling

infrastructure is the largest consumer of power after IT equipment.

Airflow management (AFM) remains the easiest and lowest-cost way to

improve cooling infrastructure efficiency and capacity.

However, even if your site makes strides to improve AFM, you must keep up

the efforts and closely manage them over time.

And Now…

Let’s discuss the metrics.

Are you calculating key AFM metrics

monthly?!

6 Key AFM metrics to include in your monthly report:

What is it?

A metric Upsite developed to estimate the utilization of the cooling infrastructure.

What does it mean?

Calculating the CCF is the quickest and easiest way to determine potential gains to be realized by AFM improvements.

How is it calculated?

By converting the total rated (stated) cooling capacity to kW, and dividing by 110% of the IT critical load (kW).

Metric 1: Cooling Capacity Factor

Total rated cooling capacity (210 tons x 3.52) = 739 kW

110% of the IT critical load = 259 kW

CCF = 2.8 (739/259)

Running cooling capacity is 280% of the load

CCF Rating Interpretation

1.0 to 1.1 There is little to no redundant cooling or room for reducing OpEx.

1.1 to 1.2 The number of running cooling units is very closely coupled to the heat load

in the room.

1.2 to 1.5 There is moderate opportunity for savings from turning off cooling units.

This can often only be done once AFM improvements have been effectively

implemented.

1.5 to 3.0 Most common. These rooms have substantial opportunity to reduce

operating cost, improve the IT environment, and increase the IT load that

can be effectively cooled. Rooms in this range often have significant

stranded cooling capacity that can be freed up by improving AFM.

> 3.0 Have great potential for improvement since the total rated cooling capacity

of running units is at least three times 110% of the IT load.

Metric 1: Cooling Capacity Factor (cont.)

http://www.upsite.com/resources/ccf-sign-up/

Metric 1: Cooling Capacity Factor (cont.)

Calculate your CCF using the free online Cooling Capacity

Factor Calculator:

Perforated tiles and grates should only be located in front of equipment that

requires conditioned air for cooling. The percentage of properly located

perforated tiles and grates should be 100%. Replace all perforated tiles and

grates located in dedicated hot aisles and open spaces with solid tiles.

Metric 2: Perforated Tile & Grate Placement

Helpful Tip: Start with an

infrared temperature survey

(instructions on next slide)

How to conduct an infrared temperature survey

Metric 2: Perforated Tile & Grate Placement

Step 1:

First, use an infrared thermometer to measure the intake air temperatures. If

they are all cool and the ceiling is cool, then there is more conditioned air being

delivered to the aisle than needed.

Step 2:

Add or remove perforated tiles and grates in cold aisles to make all IT

equipment intake air temperatures as low and even as possible.

The primary purpose of a computer room is to provide a stable and

appropriate intake air temperature for IT equipment. As such, computer rooms

are in either of two categories, those with and those without intake air

temperature problems.

Metric 3: IT Equipment Intake Temperatures

Raised floor bypass open area is made up of unsealed cable openings and

penetrations, and perforated tiles placed in hot aisles or open areas. The

percentage of raised floor bypass open area is calculated by dividing the total

bypass open area by the total open area in the raised floor. The percentage of

bypass open area should be less than 10%.

Metric 4: Raised Floor Open Area Percentage

Image courtesy of Tateinc.com

Install blanking panels that seal effectively, with no gaps between panels, in all

open spaces within cabinets. Spaces between cabinets and under cabinets

need to be sealed to retain conditioned air at the IT equipment face and to

prevent hot exhaust air from flowing into the cold aisle. The percentage of

open U spaces filled with blanking panels should be 100%. Close all open

space of the vertical plane of IT equipment intakes. Install blanking panels,

seal under cabinets, and seal between mounting rails and sides of cabinets.

Metric 5: Blanking Panel Utilization

The utilization of rack space is important to understanding how well the

valuable space of a computer room is being utilized. Cooling capacity and

planning are closely related to rack space utilization.

Metric 6: Rack Space Utilization

Something else you need to consider…

In addition to the 6 metrics to monitor regularly, another key aspect of your

overall AFM improvement strategy is to regularly validate your IT cooling

equipment performance. Here’s what to look for:

Calibration of Cooling Unit Return-Air Temperature and Relative

Humidity Sensors

Presence of Latent Cooling

Return Air Temperature vs. Standard Rated Conditions

Manufacturers rate their cooling units on standard return-air

conditions, typically 75 degrees (F) with a 45 percent relative humidity

(RH%). However, since most sites run their cooling units with set

points lower than standard conditions, the rated capacity cannot be

delivered. This results in the very costly condition of more cooling units

running because the cooling unit’s cooling capacity decreases at lower

return-air temperatures.

Return Air Temperature vs. Standard Rated

Conditions

In some configurations, high relative humidity (RH%) and low return

air temperatures can result in condensation forming on cooling unit

coils (i.e. latent cooling). Moisture condensing on cooling unit coils

actually gives off heat that consumes some of a cooling unit’s cooling

capacity, stranding capacity that could otherwise be used to reduce

the air temperature of the supply air to IT equipment.

Presence of Latent Cooling

To accurately assess cooling unit return-air temperatures and latent

cooling conditions, ensure that you regularly calibrate all cooling unit

return-air temperature and relative humidity (RH%) sensors.

Calibration of Cooling Unit Return-Air

Temperature and Relative Humidity Sensors

So now what?

Now it’s time to get started using these steps:

1. Estimate cooling unit utilization with Cooling Capacity Factor (CCF).

2. Assess implementation of airflow management best practices.

3. Calculate airflow management metrics.

4. Implement improvements (in the correct order).

5. Maintain with organizational best practices.

Step 1: Determine Cooling Utilization via

the Cooling Capacity Factor (CCF)

Start with our free online Cooling Capacity Factor Calculator at

http://www.upsite.com/resources/ccf-sign-up/

Step 2: Assess Current AFM Initiatives

Raised Floor The Rack The Row

Step 3: Implement Improvements - In The Correct Order!

Implement airflow management initiatives using our 4 Rs methodology, in

the correct order.

Learn more about our 4 Rs Methodology at

http://www.upsite.com/blog/4-steps-optimizing-computer-room-airflow-management/

Ensure IT and Facilities are coordinated.

Document processes for personnel

working the room.

Implement training protocols.

Clearly state company objectives that

cooling optimization can support.

Schedule regular assessments.

Limit access to computer room.

Centralize decision-making process for changes.

Regular reporting to senior management (e.g. PUE, CCF, utility bill, other related

trends to track).

Appoint a ‘cooling czar’ and give them authority.

Step 4: Maintain with Organizational Best

Practices

Conclusion

A computer room is a dynamic environment, so it’s

unrealistic to expect that these key AFM metrics would

not drift over time. Therefore, closely tracking each

will help assure that your cooling infrastructure will be

operating at maximum capacity, maximum reliability,

and the lowest operating cost (and best PUE) in 2015.

Want to learn more?

Download our free Cooling Capacity Factor white paper to find out

how much you could be saving on cooling costs:

Upsite.com/cooling-capacity-factor-white-paper