scholarly journals Impact of Fan Airflow of IT Equipment on Thermal Environment and Energy Consumption of a Data Center

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6166
Author(s):  
Naoki Futawatari ◽  
Yosuke Udagawa ◽  
Taro Mori ◽  
Hirofumi Hayama
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Data Center ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Operating Efficiency ◽  
Inlet Temperature ◽  
Total Energy Consumption ◽  
Air Supply ◽  
Machine Room

Energy-saving in regard to heating, ventilation, and air-conditioning (HVAC) in data centers is strongly required. Therefore, to improve the operating efficiency of the cooling equipment and extend the usage time of the economizer used for cooling information-technology equipment (ITE) in a data center, it is often the case that a high air-supply temperature within the range in which the ITE can be sufficiently cooled is selected. In the meantime, it is known that when the ambient temperature of the ITE rises, the speed of the built-in cooling fan increases. Acceleration of the built-in fan is thought to affect the cooling performance and energy consumption of the data center. Therefore, a method for predicting the temperature of a data center—which simply correlates supply-air temperature with ITE inlet temperature by utilizing existing indicators, such as air-segregation efficiency (ASE)—is proposed in this study. Moreover, a method for optimizing the total energy consumption of a data center is proposed. According to the prediction results obtained under the assumption of certain computer-room air-conditioning (CRAC) conditions, by lowering the ITE inlet temperature from 27 °C to 18 °C, the total energy consumption of the machine room is reduced by about 10%.

Design of Passive Two-Phase Thermosyphons for Server Cooling

2019 ◽  
Author(s):  
Raffaele L. Amalfi ◽  
Jackson B. Marcinichen ◽  
John R. Thome ◽  
Filippo Cataldo
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Efficient ◽  
High Efficiency ◽  
Cooling System ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Annual Growth Rate ◽  
Total Energy Consumption ◽  
Two Phase

Abstract The main objective of this paper is to utilize an improved version of the simulator presented at InterPACK 2017 to design a thermosyphon system for energy-efficient heat removal from 2-U servers used in high-power datacenters. Currently, between 25% and 45% of the total energy consumption of a datacenter (this number does not include the energy required to drive the fans at the server-level) is dedicated to cooling, and with a predicted annual growth rate of about 15% (or higher) coupled with the plan of building numerous new datacenters to handle the “big data” storage and processing demands of emerging 5G networks, artificial intelligence, electrical vehicles, etc., the development of novel, high efficiency cooling technologies becomes extremely important for curbing the use of energy in datacenters. Notably, going from air cooling to two-phase cooling, not only enables the possibility to handle the ever higher heat fluxes and heat loads of new servers, but it also provides an energy-efficient solution to be implemented for all servers of a datacenter to reduce the total energy consumption of the entire cooling system. In that light, a pseudo-chip with a footprint area of 4 × 4 cm2 and a maximum power dissipation of 300 W (corresponding heat flux of about 19 W/cm2), will be assumed as a target design for our novel thermosyphon-based cooling system. The simulator will be first validated against an independent database and then used to find the optimal design of the chip’s thermosyphon. The results demonstrate the capability of this simulator to model all of the thermosyphon’s components (evaporator, condenser, riser and downcomer) together with overall thermal performance and creation of operational maps. Additionally, the simulator is used here to design two types of passive two-phase systems, an air- and a liquid-cooled thermosyphon, which will be compared in terms of thermal-hydraulic performance. Finally, the simulator will be used to perform a sensitivity analysis on the secondary coolant side conditions (inlet temperature and mass flow rate) to evaluate their effect on the system performance.

Dynamic Control of Airflow Balance in Data Centers

2019 ◽  
Author(s):  
Stephen Paul Linder ◽  
Jim Van Gilder ◽  
Yan Zhang ◽  
Enda Barrett
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Pressure Sensor ◽  
Data Center ◽  
Data Centers ◽  
Dynamic Control ◽  
Air Pressure ◽  
Cooling Efficiency ◽  
Total Energy Consumption ◽  
Flow Network

Abstract Efficient cooling of data center infrastructure is an important way to reduce total energy consumption. Containment, with separation of hot and cold airflows has allowed significant increase in efficiencies. However, balancing the airflow, so that IT equipment in an aisle only receives the cooling airflow that that aisle needs is still often not done. We propose a new architecture where IT racks are clustered together with shared hot aisles ducted to a common ceiling plenum. Each aisle has an actively controlled damper used to balance the airflow to the cooling infrastructure. Using a differential air pressure sensor in each aisle and an algorithm designed to balance the flow network, we minimize the cooling airflow and maximize cooling efficiency.

scholarly journals Impact Analysis of Window-Wall Ratio on Heating and Cooling Energy Consumption of Residential Buildings in Hot Summer and Cold Winter Zone in China

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Qiaoxia Yang ◽  
Meng Liu ◽  
Chang Shu ◽  
Daniel Mmereki ◽  
Md. Uzzal Hossain ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Demand ◽  
Air Conditioning ◽  
Impact Analysis ◽  
Residential Buildings ◽  
Operation Mode ◽  
Cold Winter ◽  
Total Energy Consumption ◽  
Air Conditioning System

In order to assess the optimal window-wall ratio and the proper glazing type in different air conditioning system operation modes of residential buildings for each orientation in three typical cities in hot summer and cold winter zone: Chongqing, Shanghai, and Wuhan simulation models were built and analyzed using Designer’s Simulation Toolkit (DeST). The study analyzed the variation of annual heating energy demand, annual cooling energy demand, and the annual total energy consumption in different conditions, including different orientations, patterns of utilization of air conditioning system, window-wall ratio, and types of windows. The results show that the total energy consumption increased when the window-wall ratio is also increased. It appears more obvious when the window orientation is east or west. Furthermore, in terms of energy efficiency, low-emissivity (Low-E) glass performs better than hollow glass. From this study, it can be concluded that the influence and sensitivity of window-wall ratio on the total energy consumption are related to the operation mode of air conditioning system, the orientation of outside window, and the glazing types of window. The influence of the factors can be regarded as reference mode for the window-wall ratio when designing residential buildings.

Energy Modeling of Air-Cooled Data Centers: Part I—The Optimization of Enclosed Aisle Configurations

2011 ◽  
Author(s):  
Dustin W. Demetriou ◽  
H. Ezzat Khalifa
Keyword(s):  
Energy Consumption ◽  
Power Consumption ◽  
Temperature Rise ◽  
Data Center ◽  
Data Centers ◽  
Total Power ◽  
Optimum Operating ◽  
Cooling Power ◽  
Inlet Temperature ◽  
Total Energy Consumption

The work presented in this paper describes a simplified thermodynamic model that can be used for exploring optimization possibilities in air-cooled data centers. The model is used to parametrically evaluate the total energy consumption of the data center cooling infrastructure for data centers that utilize aisle containment. The analysis highlights the importance of reducing the total power required for moving the air within the CRACs, the plenum, and the servers, rather than focusing primarily or exclusively on reducing the refrigeration system’s power consumption and shows the benefits of bypass recirculation in enclosed aisle configurations. The analysis shows a potential for as much as a 57% savings in cooling infrastructure energy consumption by utilizing an optimized enclosed aisle configuration with bypass recirculation, instead of a traditional enclosed aisle, where all the data center exhaust is forced to flow through the computer room air conditioners (CRACs), for racks with a modest temperature rise (∼10°C). However, for racks with larger temperature rise (> ∼20°C), the saving are less than 5%. Furthermore, for servers whose fan speed (flow rate) varies as a function of inlet temperature, the analysis shows that the optimum operating regime for enclosed aisle data centers falls within a very narrow band and that power reductions are possible by lowering the uniform server inlet temperature in the enclosed aisle from 27°C to 22°C. However, the optimum CRAC exit temperature over the 22-to-27°C range of enclosed cold aisle temperature falls between ∼16 and 20°C because a significant reduction in the power consumption is possible through the use of bypass recirculation. Without bypass recirculation, the power consumption for a server inlet temperature of 22°C enclosed aisle case with a server temperature rise of 10°C would be a whopping 43% higher than with bypass recirculation. It is worth noting that, without bypass recirculation maintaining the enclosed cold aisle at 22°C instead of 27°C would reduce power consumption by 48%. It is also shown that enclosing the aisles together with bypass recirculation (when beneficial) also reduces the dependence of the optimum cooling power on server temperature rise.

scholarly journals Energy Audit: A Case Study in FTK Building Universiti Malaysia Pahang

2018 ◽  
Vol 5 (2) ◽  
pp. 91-101
Author(s):  
Roziah Zailan ◽  
Mohd Tarmizy Che Kar
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Total Energy ◽  
Energy Saving ◽  
Air Conditioning ◽  
Building Energy ◽  
Energy Index ◽  
Energy Audit ◽  
Total Energy Consumption ◽  
Energy Conservation Measures

The energy audit program was carried out for Faculty of Engineering Technology (FTK), University Malaysia Pahang by internal energy audit team. This paper presented annual energy consumption trend for FTK building, measurement finding for room data survey (air conditioning temperature and humidity comfort performance & CO2 level for air quality) and lighting, Building Energy Index (BEI) value and appropriate recommendation in regards of energy saving practice and technological solution. According to those analysis, value for Building Energy Index (BEI) in FTK building is 98.035 kWh/m2/year, Air Conditioning Energy Index (ACEI) is 73.254 kWh/m2/year while for Lighting Energy Index (LEI) is 11.402 kWh/m2/year. Total energy consumption estimated for 2017 is 31, 7951.375 kWh per year. The implementation of the proposed energy conservation measures were expected to give positive results where the total cost saving per year is estimated about RM 48,551.20. Finally, it was recommended to implement three major energy conservation measures (ECMs) in specific: implementation of Sustainable energy management system (SEMS), maintenance of air conditioning system and retrofitting of LED lighting. As a result, FTK is targeted to achieve 30% annual energy saving about from the total energy consumption.

Energy savings potential of new aeration system: Full scale trials

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
A. Lazić ◽  
V. Larsson ◽  
Å. Nordenborg
Keyword(s):  
Control System ◽  
Energy Consumption ◽  
Total Energy ◽  
Energy Savings ◽  
Treatment Plant ◽  
Full Scale ◽  
Total Energy Consumption ◽  
Aeration System ◽  
Fine Bubble ◽  
Aeration Control

The objective of this work is to decrease energy consumption of the aeration system at a mid-size conventional wastewater treatment plant in the south of Sweden where aeration consumes 44% of the total energy consumption of the plant. By designing an energy optimised aeration system (with aeration grids, blowers, controlling valves) and then operating it with a new aeration control system (dissolved oxygen cascade control and most open valve logic) one can save energy. The concept has been tested in full scale by comparing two treatment lines: a reference line (consisting of old fine bubble tube diffusers, old lobe blowers, simple DO control) with a test line (consisting of new Sanitaire Silver Series Low Pressure fine bubble diffusers, a new screw blower and the Flygt aeration control system). Energy savings with the new aeration system measured as Aeration Efficiency was 65%. Furthermore, 13% of the total energy consumption of the whole plant, or 21 000 €/year, could be saved when the tested line was operated with the new aeration system.

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