Effect of Relative Humidity, Temperature and Gaseous and Particulate Contaminations on Information Technology Equipment Reliability

2015 ◽  
Author(s):  
Prabjit Singh ◽  
Levente Klein ◽  
Dereje Agonafer ◽  
Jimil M. Shah ◽  
Kanan D. Pujara
Keyword(s):  
Information Technology ◽  
High Temperature ◽  
Relative Humidity ◽  
Data Center ◽  
Data Centers ◽  
Electronic Equipment ◽  
Worst Case ◽  
Equipment Reliability ◽  
Short Period ◽  
Temperature And Humidity

The energy used by information technology (IT) equipment and the supporting data center equipment keeps rising as data center proliferation continues unabated. In order to contain the rising computing costs, data center administrators are resorting to cost cutting measures such as not tightly controlling the temperature and humidity levels and in many cases installing air side economizers with the associated risk of introducing particulate and gaseous contaminations into their data centers. The ASHRAE TC9.9 subcommittee, on Mission Critical Facilities, Data Centers, Technology Spaces, and Electronic Equipment, has accommodated the data center administrators by allowing short period excursions outside the recommended temperature-humidity range, into allowable classes A1-A3. Under worst case conditions, the ASHRAE A3 envelope allows electronic equipment to operate at temperature and humidity as high as 24°C and 85% relative humidity for short, but undefined periods of time. This paper addresses the IT equipment reliability issues arising from operation in high humidity and high temperature conditions, with particular attention paid to the question of whether it is possible to determine the all-encompassing x-factors that can capture the effects of temperature and relative humidity on equipment reliability. The role of particulate and gaseous contamination and the aggravating effects of high temperature and high relative humidity will be presented and discussed. A method to determine the temperature and humidity x-factors, based on testing in experimental data centers located in polluted geographies, will be proposed.

Data Center Equipment Reliability Concerns—Contamination Issues, Standards Actions, and Case Studies

2013 ◽  
Author(s):  
Chris Muller ◽  
Chuck Arent ◽  
Henry Yu
Keyword(s):  
Case Studies ◽  
Data Center ◽  
Data Centers ◽  
Electronic Equipment ◽  
Circuit Board ◽  
Lead Free ◽  
Reliable Operation ◽  
Contamination Assessment ◽  
Equipment Reliability ◽  
Equipment Failures

Abstract Lead-free manufacturing regulations, reduction in circuit board feature sizes and the miniaturization of components to improve hardware performance have combined to make data center IT equipment more prone to attack by corrosive contaminants. Manufacturers are under pressure to control contamination in the data center environment and maintaining acceptable limits is now critical to the continued reliable operation of datacom and IT equipment. This paper will discuss ongoing reliability issues with electronic equipment in data centers and will present updates on ongoing contamination concerns, standards activities, and case studies from several different locations illustrating the successful application of contamination assessment, control, and monitoring programs to eliminate electronic equipment failures.

Experimental Description of Information Technology Equipment Reliability Exposed to a Data Center Using Airside Economizer Operating in Recommended and Allowable ASHRAE Envelopes in an ANSI/ISA Classified G2 Environment

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Oluwaseun Awe ◽  
Jimil M. Shah ◽  
Dereje Agonafer ◽  
Prabjit Singh ◽  
Naveen Kannan ◽  
...  
Keyword(s):  
Information Technology ◽  
Data Center ◽  
Data Centers ◽  
Operating Cost ◽  
Weather Data ◽  
Air Cooling ◽  
Single Server ◽  
Severity Level ◽  
Equipment Reliability ◽  
Free Air

Abstract Airside economizers lower the operating cost of data centers by reducing or eliminating mechanical cooling. It, however, increases the risk of reliability degradation of information technology (IT) equipment due to contaminants. IT Equipment manufacturers have tested equipment performance and guarantee the reliability of their equipment in environments within ISA 71.04-2013 severity level G1 and the ASHRAE recommended temperature-relative humidity (RH) envelope. IT Equipment manufacturers require data center operators to meet all the specified conditions consistently before fulfilling warranty on equipment failure. To determine the reliability of electronic hardware in higher severity conditions, field data obtained from real data centers are required. In this study, a corrosion classification coupon experiment as per ISA 71.04-2013 was performed to determine the severity level of a research data center (RDC) located in an industrial area of hot and humid Dallas. The temperature-RH excursions were analyzed based on time series and weather data bin analysis using trend data for the duration of operation. After some period, a failure was recorded on two power distribution units (PDUs) located in the hot aisle. The damaged hardware and other hardware were evaluated, and cumulative corrosion damage study was carried out. The hypothetical estimation of the end of life of components is provided to determine free air-cooling hours for the site. There was no failure of even a single server operated with fresh air-cooling shows that using evaporative/free air cooling is not detrimental to IT equipment reliability. This study, however, must be repeated in other geographical locations to determine if the contamination effect is location dependent.

Behavioural aspects of microhabitat segregation of different age stages in the wetland land snail Vertigo moulinsiana (Eupulmonata: Vertiginidae) in the laboratory

2020 ◽  
Vol 86 (3) ◽  
pp. 228-232
Author(s):  
Zofia Książkiewicz-Parulska
Keyword(s):  
High Temperature ◽  
Land Snail ◽  
Snail Species ◽  
High Humidity ◽  
Short Period ◽  
Temperature And Humidity ◽  
In The Wild ◽  
Different Response ◽  
Behavioural Aspects ◽  
Microhabitat Segregation

ABSTRACT This laboratory study investigated behavioural differences between adults and juveniles of the wetland land snail species Vertigo moulinsiana with respect to temperature and humidity. Juveniles of V. moulinsiana, for example, tend to remain within the shaded, humid and cool layer of the litter, while adults usually climb above wet vegetation to a height of over 2 m. Adults are thus exposed to greater variation in temperature and humidity than juveniles. My experiments showed that adults of V. moulinsiana remain active longer than juveniles when subject to high temperature (36 °C) and low relative humidity (RH 30%). Conversely, juveniles stay active longer than adults in high humidity (22 °C, RH 100%). A short period of starvation lengthened the time needed for the juveniles to become active after dormancy, possibly indicating a different response between adults and juveniles to lack of nutritional reserves. These behavioural differences to food availability and the risk of water loss correspond to the microhabitat differences observed between adults and juveniles in the wild.

A New Conception of Load Balancing in Cloud Computing Using Tasks Classification Levels

2018 ◽  
Vol 8 (4) ◽  
pp. 118-133 ◽  
Author(s):  
Fahim Youssef ◽  
Ben Lahmar El Habib ◽  
Rahhali Hamza ◽  
Labriji El Houssine ◽  
Eddaoui Ahmed ◽  
...  
Keyword(s):  
Load Balancing ◽  
Data Center ◽  
Execution Time ◽  
Data Centers ◽  
Virtual Machines ◽  
Service Providers ◽  
Cloud Service ◽  
Mathematical Functions ◽  
Worst Case ◽  
Cloud Users

Cloud users can have access to the service based on “pay as you go.” The daily increase of cloud users may decrease the performance, the availability and the profitability of the material and software resources used in cloud service. These challenges were solved by several load balancing algorithms between the virtual machines of the data centers. In order to determine a new load balancing improvement; this article's discussions will be divided into two research axes. The first, the pre-classification of tasks depending on whether their characteristics are accomplished or not (Notion of Levels). This new technique relies on the modeling of tasks classification based on an ascending order using techniques that calculate the worst-case execution time (WCET). The second, the authors choose distributed datacenters between quasi-similar virtual machines and the modeling of relationship between virtual machines using the pre-scheduling levels is included in the data center in terms of standard mathematical functions that controls this relationship. The key point of the improvement, is considering the current load of the virtual machine of a data center and the pre-estimation of the execution time of a task before any allocation. This contribution allows cloud service providers to improve the performance, availability and maximize the use of virtual machines workload in their data centers.

Achieving Ultra-Low Energy Consumption in Data Center Mechanical Systems Through Indirect Airside Economization

2016 ◽  
Author(s):  
Dan Comperchio ◽  
Sameer Behere
Keyword(s):  
Information Technology ◽  
Energy Consumption ◽  
Data Center ◽  
Energy Use ◽  
Data Centers ◽  
Mechanical Systems ◽  
Electrical Energy ◽  
Vapor Compression ◽  
Ambient Conditions ◽  
Air Temperatures

Data center cooling systems have long been burdened by high levels of redundancy requirements, resulting in inefficient system designs to satisfy a risk-adverse operating environment. As attitudes, technologies, and sustainability awareness change within the industry, data centers are beginning to realize higher levels of energy efficiency without sacrificing operational security. By exploiting the increased temperature and humidity tolerances of the information technology equipment (ITE), data center mechanical systems can leverage ambient conditions to operate in economization mode for increased times during the year. Economization provides one of the largest methodologies for data centers to reduce their energy consumption and carbon footprint. As outside air temperatures and conditions become more favorable for cooling the data center, mechanical cooling through vapor-compression cycles is reduced or entirely eliminated. One favorable method for utilizing low outside air temperatures without sacrificing indoor air quality is through deploying rotary heat wheels to transfer heat between the data center return air and outside air without introducing outside air into the white space. A metal corrugated wheel is rotated through two opposing airstreams with varying thermal gradients to provide a net cooling effect at significantly reduced electrical energy over traditional mechanical cooling topologies. To further extend the impacts of economization, data centers are also able to significantly raise operating temperatures beyond what is traditionally found in comfort cooling applications. The increase in the dry bulb temperature provided to the inlet of the information technology equipment, as well as an elevated temperature rise across the equipment significantly reduces the energy use within a data center.

Development of a Technique to Measure Deliquescent Relative Humidity of Particulate Contaminants and Determination of the Operating Relative Humidity of a Data Center

2019 ◽  
Author(s):  
Jimil M. Shah ◽  
Roshan Anand ◽  
Satyam Saini ◽  
Rawhan Cyriac ◽  
Dereje Agonafer ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Data Center ◽  
Printed Circuit Boards ◽  
Data Centers ◽  
Operating Conditions ◽  
Test Method ◽  
Dust Particles ◽  
Circuit Boards ◽  
Printed Circuit

Abstract A remarkable amount of data center energy is consumed in eliminating the heat generated by the IT equipment to maintain and ensure safe operating conditions and optimum performance. The installation of Airside Economizers, while very energy efficient, bears the risk of particulate contamination in data centers, hence, deteriorating the reliability of IT equipment. When RH in data centers exceeds the deliquescent relative humidity (DRH) of salts or accumulated particulate matter, it absorbs moisture, becomes wet and subsequently leads to electrical short circuiting because of degraded surface insulation resistance between the closely spaced features on printed circuit boards. Another concern with this type of failure is the absence of evidence that hinders the process of evaluation and rectification. Therefore, it is imperative to develop a practical test method to determine the DRH value of the accumulated particulate matter found on PCBs (Printed Circuit Boards). This research is a first attempt to develop an experimental technique to measure the DRH of dust particles by logging the leakage current versus RH% (Relative Humidity percentage) for the particulate matter dispensed on an interdigitated comb coupon. To validate this methodology, the DRH of pure salts like MgCl2, NH4NO3 and NaCl is determined and their results are then compared with their published values. This methodology was therefore implemented to help lay a modus operandi of establishing the limiting value or an effective relative humidity envelope to be maintained at a real-world data center facility situated in Dallas industrial area for its continuous and reliable operation.

scholarly journals Dose uniformity of budesonide Easyhaler® under simulated real-life conditions and with low inspiration flow rates

2017 ◽  
Vol 15 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Jussi Haikarainen ◽  
Paula Rytilä ◽  
Sirkku Roos ◽  
Sirpa Metsärinne ◽  
Anita Happonen
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Real Life ◽  
Dry Powder Inhaler ◽  
Dose Delivery ◽  
Flow Rates ◽  
Life Conditions ◽  
Dose Uniformity ◽  
Temperature And Humidity ◽  
Delivered Dose

Budesonide Easyhaler® multidose dry powder inhaler is approved for the treatment of asthma. Objectives were to determine the delivered dose (DD) uniformity of budesonide Easyhaler® in simulated real-world conditions and with different inspiration flow rates (IFRs). Three dose delivery studies were performed using 100, 200, and 400 µg/dose strengths of budesonide. Dose uniformity was assessed during in-use periods of 4–6 months after exposure to high temperature (30°C) and humidity (60% relative humidity) and after dropping and vibration testing. The influence of various IFRs (31, 43, and 54 L/min) on the DD was also investigated. Acceptable dose uniformity was declared when mean DD were within 80–120% of expected dose; all data reported descriptively. DD was constant (range: 93–109% of expected dose) at all in-use periods and after exposure to high temperature and humidity for a duration of up to 6 months. DD post-dropping and -vibration were unaffected (range 98–105% of expected dose). Similarly, DD was constant and within 10% of expected dose across all IFRs. Results indicate that budesonide Easyhaler® delivers consistently accurate doses in various real-life conditions. Budesonide Easyhaler® can be expected to consistently deliver a uniform dose and improve asthma control regardless of high temperature and humidity or varying IFR.

A Thermo-Mechanical Study on Vertically Split Distribution-Wet Cooling Media Used in Data Centers

2018 ◽  
Author(s):  
Mullaivendhan Varadharasan ◽  
Dereje Agonafer ◽  
Ahmed Al Khazraji ◽  
Jimil Shah ◽  
Ashwin Siddarth ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Flow Rate ◽  
Data Center ◽  
Data Centers ◽  
Air Flow ◽  
Scale Formation ◽  
Flow Rates ◽  
Direct Evaporative Cooling ◽  
The Media ◽  
Cooling Media

Direct evaporative cooling (DEC) is widely used in the data center cooling units to maintain the air condition inside the data centers. Often, the flow rate of the water over the wet cooling media in this DEC process is frequently varied to maintain the air condition inside the data centers based on changing weather conditions. Though the adopted method helps to control the air temperature and relative humidity, the scale formation occurs on the surface of wet cooling media due to the frequent variation of the flow rate and deposition of minerals present in the water at low flow rate values, which increases the total weight of the wet cooling media and it can lead to a wet cooling media collapse. In this paper an alternative and simplified method to control the air condition is presented. A vertically split wet cooling media is designed and tested in a commercial CFD tool to analyze the temperature and relative humidity parameters of the inlet and outlet air to the wet cooling media, in this approach the sections of the media can either be completely wet or completely dry which can potentially avoid the scale formation on the surface of the wet cooling media. In addition to the temperature and relative humidity parameters against the air flow rates, the pressure drop and cooling efficiency values for varied air flow rates are studied. The vertically split wet cooling media configurations are achieved by sectioning the media in to equal and unequal sections. In the equal configuration, media has been tested for 0%, 50% and 100% wetting conditions, and in the unequal configuration, media has been tested for 0%, 33%, 66% and 100% wetting conditions. The test results are used to emphasis the advantage of this staged wetting method and gives a possible solution to the scale formation problem on the wet cooling media during the direct evaporative cooling process in the data center.

Effect of Data Center Layout on Rack Inlet Air Temperatures

2005 ◽  
Author(s):  
Roger Schmidt ◽  
Madhusudan Iyengar
Keyword(s):  
Data Center ◽  
Air Conditioning ◽  
Data Centers ◽  
Floor Tile ◽  
Electronic Equipment ◽  
Macro Level ◽  
Thermal Profile ◽  
Air Temperatures ◽  
Switching Equipment

The heat dissipated by large servers and switching equipment is reaching levels that make it very difficult to cool these systems in data centers or telecommunications rooms. Some of the highest powered systems are dissipating upwards of 4000 watts/ft2(43,000 watts/m2) based on the equipment footprint. When systems dissipate this amount of heat and then are clustered together within a data center significant cooling challenges can result. This paper describes the thermal profile of 3 data center layouts (2 are of the same data center but different points in time with a different layout). Detailed measurements of all three were taken: electronic equipment power usage; perforated floor tile airflow; cable cutout airflow; computer room air conditioning (CRAC) airflow, temperatures and power usage; electronic equipment inlet air temperatures. Although the detailed measurements were recorded this paper will focus at the macro level results of the data center to see if some patterns present themselves that might be helpful for future guidelines of data center layout for optimized cooling. Specifically, areas of the data center where racks have similar inlet air temperatures are examined relative to the rack and CRAC unit layout.

Qualitative Study of Cumulative Corrosion Damage of IT Equipment in a Data Center Utilizing Air-Side Economizer

2016 ◽  
Author(s):  
Jimil M. Shah ◽  
Oluwaseun Awe ◽  
Pavan Agarwal ◽  
Iziren Akhigbe ◽  
Dereje Agonafer ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Data Center ◽  
Data Centers ◽  
Energy Savings ◽  
Evaporative Cooling ◽  
Corrosion Damage ◽  
Air Cooling ◽  
Single Server ◽  
Severity Level ◽  
Particulate Contamination

Deployment of air-side economizers in data centers is rapidly gaining acceptance to reduce the cost of energy by reducing the hours of operation of CRAC units. Use of air-side economizers has the associated risk of introducing gaseous and particulate contamination into data centers, thus, degrading the reliability of Information Technology (IT) equipment. Sulfur-bearing gaseous contamination is of concern because it attacks the copper and silver metallization of the electronic components causing electrical opens and/or shorts. Particulate contamination with low deliquescence relative humidity is of concern because it becomes wet and therefore electrically conductive under normal data center relative humidity conditions. IT equipment manufacturers guarantee the reliability of their equipment operating in environment within ISA 71.04-2013 severity level G1 and within the ASHRAE recommended temperature-relative humidity envelope. The challenge is to determine the reliability degrading effect of contamination severity levels higher than G1 and the temperature and humidity allowable ranges A1–A3 well outside the recommended range. This paper is a first attempt at addressing this challenge by studying the cumulative corrosion damage to IT equipment operated in an experimental data center located in Dallas, known to have contaminated air with ISA 71.04-2013 severity level G2. The data center is cooled using an air-side economizer. This study serves several purposes including: the correlation of equipment reliability to levels of airborne corrosive contaminants and the study of the degree of reliability degradation when the equipment is operated, outside the recommended envelope, in the allowable temperature-relative humidity range in geographies with high levels of gaseous and particulate contamination. The operating and external conditions of a modular data center, located in a Dallas industrial area, using air-side economizer is described. The reliability degradation of servers exposed to outside air via an airside economizer was determined qualitatively examining the corrosion of components in the servers and comparing the results to the corrosion of components in a non-operating server stored in a protective environment. The corrosion-related reliability of the servers over almost the life of the product was related to continuous temperature and relative humidity for the duration of the experiment. This work provides guidance for data center administration for similar environment. From an industry perspective, it should be noted that in the four years of operation in the hot and humid Dallas climate using only evaporative cooling or fresh air cooling, we have not seen a single server failure in our research pod. That performance should highlight an opportunity for significant energy savings for data center operators in a much broader geographic area than currently envisioned with evaporative cooling.

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