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This paper focuses on the effect on inlet rack air temperatures when rack flowrates are reduced. Reduced flowrates for the same heat loads results in higher air temperature differences across the rack and thereby higher air temperatures exiting the rack. The effect of the higher rack exhaust temperatures on the inlet rack air temperatures is the focus of this investigation. Only the above floor (raised floor) flow and temperature distributions were analyzed for a range of rack flowrates and with various flowrates exhausting from the perforated tiles. A Computational Fluid Dynamic (CFD) model was generated for the room with electronic equipment installed on a raised floor with particular focus on the effects on rack inlet temperatures of these high powered racks. Fourty racks of data processing (DP) equipment were arranged in rows in a data center cooled by chilled air exhausting from perforated floor tiles. The chilled air was provided by four A/C units placed inside a room 12.1 m wide × 13.4 m long. Since the arrangement of the racks in the data center was symmetric only one-half of the data center was modeled. The numerical modeling was performed using a commercially available finite control volume computer code called Flotherm (Trademark of Flomerics, Inc.). The flow was modeled using the k-e turbulence model. Results are displayed to provide some guidance on the design and layout of a data center.Copyright © 2003 by ASME

This paper focuses on the effect on inlet rack air temperatures when adjacent racks are removed. Only the above floor (raised floor) flow and temperature distributions were analyzed for various air flowrates exhausting from the perforated tiles and the rack. A Computational Fluid Dynamic (CFD) model was generated for the room with electronic equipment installed on a raised floor with particular focus on the effects on rack inlet temperatures of these high powered racks. The baseline case was with forty racks of data processing (DP) equipment arranged in rows in a data center cooled by chilled air exhausting from perforated floor tiles. The chilled air was provided by four A/C units placed inside a room 12.1 m wide × 13.4 m long. Since the arrangement of the racks in the data center was symmetric only one-half of the data center was modeled. To see the effect of missing racks adjacent to high powered racks various configurations were analyzed. The numerical modeling was performed using a commercially available finite control volume computer code called Flotherm (Trademark of Flomerics, Inc.). The flow was modeled using the k-e turbulence model. Results are displayed to provide some guidance on the design and layout of a data center.

A technique is presented which allows a data center designer or operator to achieve any desired partitioning of available airflow among the floor tiles of a raised-floor data center without resorting to trial-and-error. The output from the analysis is a tile-by-tile prescription of flow resistance characteristics (e.g., damper settings), which accomplishes the desired partitioning. The technique is derived from an electrical-circuit analogy of the airflow in the data. Each circuit branch represents one path that air may follow from the CRAC unit supply, through a particular floor tile, and ultimately back to the CRAC return. Any desired flow partitioning through tiles can be achieved by proper adjustment of tile resistances in each circuit; however, by itself, the flow network has too many unknowns to be solvable. A CFD simulation of the entire data center, in which the desired flow partitioning is specified, provides the pressure distribution above (in the room) and below (in the plenum) the floor tiles. The method is illustrated in step-by-step fashion with a simple example case.Copyright © 2003 by ASME

This paper focuses on the effect on inlet rack air temperatures as a result of maldistribution of airflows exiting the perforated tiles located adjacent to the fronts of the racks. The flow distribution exiting the perforated tiles was generated from a computational fluid dynamics (CFD) tool called Tileflow (Trademark of Innovative Research, Inc.). Both raised floor heights and perforated tile free area were varied in order to explore the effect on rack inlet temperatures. The flow distribution exiting the perforated tiles was used as boundary conditions to the above floor CFD model. A CFD model was generated for the room with electronic equipment installed on a raised floor. Fourty racks of data processing (DP) equipment were arranged in rows in a data center cooled by chilled air exhausting from perforated floor tiles. The chilled air was provided by four A/C units placed inside a room 12.1 m wide × 13.4 m long. Since the arrangement of the racks in the data center was symmetric only one-half of the data center was modeled. The numerical modeling for above the raised floor was performed using a commercially available finite control volume computer code called Flotherm (Trademark of Flomerics, Inc.). The flow was modeled using the k-e turbulence model. Results are displayed to provide some guidance on the design and layout of a data center.

In raised-floor data centers, the airflow rates through the perforated tiles must meet the cooling requirements of the computer servers placed next to the tiles. The data centers house a wide range of equipment, and the heat load pattern on the floor can be quite arbitrary and changes as the data center evolves. To achieve optimum utilization of the floor space and the flexibility for rearrangement and retrofitting, the designers and managers of data centers must be able to modify the airflow rates through the perforated tiles. The airflow rates through the perforated tiles are governed primarily by the pressure distribution under the raised floor. Thus, the key to modifying the flow rates is to influence the flow field in the plenum. This paper discusses a number of techniques that can be used for controlling airflow distribution. These techniques involve changing the plenum height and open area of perforated tiles, and installing thin (solid and perforated) partitions in the plenum. A number of case studies, using a mathematical model, are presented to demonstrate the effectiveness of these techniques.

This paper describes a highly efficient and highly reliable air conditioning system suitable for use in telecommunications and information processing equipment rooms, a power supply system for this air conditioning system, and an air conditioning system for improving office amenity. The air conditioning system for telecommunications and information processing equipment rooms can be used in rooms with a high heat density (a mean density of 1 kW/m/sup 2/) for natural-convection cooled equipment. A new control method enables the air conditioner to operate economically when the outdoor air temperatures are low. The inverter back-up system is shown to be the most suitable power source for a highly reliable air conditioning system. The air conditioning system for offices with multimedia equipment uses a raised floor to provide a supply and return air space and wiring space. The air flows, very slowly, from floor to ceiling in winter and from ceiling to floor in summer, thus keeping office workers comfortable. >

A high efficiency air conditioning system has been developed for application to telecommunications equipment rooms. The design specifically addresses the cooling characteristics of natural cooling equipment and the uneven distribution of heat in equipment rooms. The system can also flexibly accommodate different equipment layouts in the room. Excellent efficiency of natural cooling equipment is achieved through the use of chambers under a raised floor for air supply and above a suspended ceiling for air return to the cooling unit. A method of calculating the air supply/return distribution is presented to optimize the airflow distribution. It is shown that rearranging the perforated raised floor panels is a practical and economical way of delivering the exact required air volume to the room. Installing the system in some actual equipment rooms, measurements were taken of the room temperature distribution and performance of the cooling system. Satisfactory results were obtained for the volume and temperature distributions. It is further found that the volume of air circulated by the cooling unit fans can be substantially reduced compared to a conventional cooling system. >

Plug-and-Play is the dream of the process tool installation in the wafer fab. One day hookup is the first step or objective towards this dream. The ProMOS project proved that this objective could be achieved through the well-organized and good coordinated efforts, as well as strong support of the contractors. The successful pre-hookup made the dreams come true. Three methods were used for different kind of tools to do the correct pre-hookup. Models or templates made of steel bars were used to determine the utility connections three dimensionally for CVD and RIE equipment. Real size layout drawings were put on the raised floor for chemical stations. For furnaces, the header with take-offs for each group of furnaces was made based on the detailed hookup micro layout and process equipment layout. All the works were followed by the daily meeting of facility engineers, process equipment engineers and contractors, which made the hookup interface clear, the schedule on time and the cost under budget. The good management has minimized the hookup time of the utilities. The best results we achieved were 0.9 day for furnaces and CVD equipment, 1.2 days for wet stations and 1.9 days for sputters after tool assembly (10 working hours per day).

Data centers are used to house multiple servers, mainframes, supercomputer systems, and storage systems used in business data processing and scientific analysis. Typically, data processing (DP) equipment is cooled using forced flow of air. Modular chillers are commonly used to cool the hot air exhausted from the DP equipment and a raised floor to recirculate the conditioned air back into the room. Therefore, data centers need well-designed ventilation systems, appropriate placement of the DP equipment, and modular chillers to ensure that the air used for cooling the processing equipment is within the desired temperature range. An important aspect of the design of data centers involves sizing of the perforated floor tiles for return of cold air, the size of the space under the raised floor, and placement of the DP equipment and modular chillers. The flow through individual perforated tiles needs to fulfil the cooling requirements of the computer equipment placed adjacent to them. The novelty of the paper lies in the treatment of the volume under the raised floor as a uniformly pressurized plenum. The accuracy of the Pressurized Plenum model is demonstrated with reference to a Computational Fluid Dynamics (CFD) analysis of the recirculating flow under the raised floor and the limits of its validity are also identified. The simple model of the volume under the raised floor enables use of the technique of Flow Network Modeling (FNM) for the prediction of the distribution of flow rates exiting from the various tiles. An inverse design method is proposed for one-step design of the perforated tiles and flow balancing plates for individual chillers. Subsequent use of the FNM technique enables assessment of the performance of the actual system. Further, modifications to an existing system design needed to accommodate the changes in the cooling requirements can also be evaluated using the FNM analysis in a simple, quick, and accurate manner. The resulting design approach is very simple and efficient, and is well suited for the design of modern data centers.

This paper focuses on the effect on inlet rack air temperatures when high-powered racks are situated amongst lower powered racks in a raised floor data center. Only the above floor (raised floor) flow and temperature distributions were analyzed for various flowrates exhausting from the perforated tiles and with one or two high powered racks placed at various locations amongst the lower powered racks. A Computational Fluid Dynamic (CFD) model was generated for the room with electronic equipment installed on a raised floor with particular focus on the effects on rack inlet temperatures of these high powered racks. Forty racks of data processing (DP) equipment were arranged in rows in a data center cooled by chilled air exhausting from perforated floor tiles. The chilled air was provided by four A/C units placed inside a room 12.1 m wide × 13.4 m long. Since the arrangement of the racks in the data center was symmetric only one-half of the data center was modeled. The numerical modeling was performed using a commercially available finite control volume computer code called Flotherm (Trademark of Flomerics, Inc.). The flow was modeled using the k-e turbulence model. Results are displayed to provide some guidance on the design and layout of a data center.Copyright © 2002 by ASME

RHIC & ATLAS Computing Facility (RACF) at BNL is a 15000 sq. ft. facility hosting the IT equipment of the BNL ATLAS WLCG Tier-1 site, offline farms for the STAR and PHENIX experiments operating at the Relativistic Heavy Ion Collider (RHIC), the BNL Cloud installation, various Open Science Grid (OSG) resources, and many other small physics research oriented IT installations. The facility originated in 1990 and grew steadily up to the present configuration with 4 physically isolated IT areas with the maximum rack capacity of about 1000 racks and the total peak power consumption of 1.5 MW. In June 2012 a project was initiated with the primary goal to replace several environmental monitoring systems deployed earlier within RACF with a single commercial hardware and software solution by SynapSense Corporation based on wireless sensor groups and proprietary SynapSense™ MapSense™ software that offers a unified solution for monitoring the temperature and humidity within the rack/CRAC units as well as pressure distribution underneath the raised floor across the entire facility. The deployment was completed successfully in 2013. The new system also supports a set of additional features such as capacity planning based on measurements of total heat load, power consumption monitoring and control, CRAC unit power consumption optimization based on feedback from the temperature measurements and overall power usage efficiency estimations that are not currently implemented within RACF but may be deployed in the future.

The Act on the Promotion Wood for Public building was enforced in October, 2010 in Japan. According to this act, a public building in a low layer assumes a wooden construction as a rule or positively uses wood. Moreover, it is expected that the building such as apartment houses comes to be made from wooden. However, the floor impact sound insulation performance of the wooden constructions is low compared with that of the concrete constructions. This paper presents the effect of floating floor (dry double system floor) and raised floor (free access floor) on floor impact sound insulation performance in wooden construction. A reference floor constructed with the wood-frame construction was installed in the floor opening of the reverberation chamber, and the floating floors or the raised floor were built on it. Then, the reductions of transmitted floor impact sound level of them were measured. The results showed that the density of the surface material influences the floor impact sound interception performance in the case of the floating floor. In addition, the reductions of transmitted floor impact sound level in wooden construction were compared with them in concrete construction in the case of the raised floor.

PIC, the Port d'Informacio Cientifica in Barcelona, Spain has provisioned a compact, highly efficient Data Centre Module in order to expand its CPU servers at a minimal energy cost. The design aims are to build an enclosure of 30 square meters or less and equip it with commodity data centre components (for example, standard gas expansion air conditioners) which can host 80 KW of CPU servers with a PUE less than 1.7 (to be compared with PIC's legacy computer room with an estimated PUE of 2.3). Forcing the use of commodity components has lead to an interesting design, where for example a raised floor is used more as an air duct rather than to install cables, resulting in an "air conditioner which computes". The module is instrumented with many thermometers whose data will be used to compare to computer room simulation programs. Also, each electrical circuit has an electric meter, yielding detailed data on power consumption. The paper will present the first experience from operating the module. Although the module has a slightly different geometry from a "container", the results can be directly applied to them.

A LEED‐Gold certified government building includes six floors of open‐plan office space that are equipped with electronic sound masking delivered from a raised floor having under‐floor air distribution (UFAD). Results of user polling show mixed results for acoustic satisfaction, with significant complaints about speech privacy, and noise from the systems interfering with users’ ability to work. This research focuses on this dissatisfaction, the general conflict between speech privacy ease of verbal communication, and acceptance of noise‐generating treatments. Little research has been done on masking delivered via UFAD, so it was also desired to further the understanding of this design as part of a larger research program by the Federal government on Green Buildings. Specific objectives were to develop and test possible remedies for this system, and improve planning of future facilities that may have masking via UFAD. On‐site measurements of masking and HVAC spectra, as well as noise reduction and observations for various conditions, were made. Post‐measurement data analysis was conducted, and experimental remedies were developed and tested. The results and recommendations will be presented.

A sound insulating floor structure comprises an underlying floor layer of a raised floor constructed by supporting a plurality of underlying floor panels at a predetermined height by means of a group of supporting legs installed on a foundation floor via elastic pedestals attached to the lower ends of the supporting legs, floor covering materials laid over the underlying floor layer, and intermediate materials laid between the underlying floor layer and the floor covering materials. The intermediate material is a hardboard or a high density fiberboard having the flexural strength of 35-50 [N/mm2], Young's modulus in flexure of 4,000-5,000 [N/mm2] and the density of 0.8-1.2 [g/cm3].

Presentation and discussion of the acoustical transmission and voice privacy issues associated with raised floor office fit out construction. Many new LEED office fit out projects are using raised floor constructions for future flexibilty and use of underfloor plenum for HVAC systems and/or technology cable plant. Issues of user expectations of privacy versus capabilities of the system are becoming more common. Case study office fit out was completed with raised floor and the extent of voice transmission due to various construction conditions limited voice privacy and created noise disruption from offices, workrooms, and conference rooms. Case study involves a law office where privacy concerns are heightened due to sensitive discussions. Measurements of noise isolation and privacy were made both before and after modifications, and results will be presented and discussed and conclusions for practitioners will be discussed.

Both laboratory component tests and field system evaluations were conducted to screen architectural designs relative to sound quality performance within a classroom, and noise intrusion between classrooms. Recognized standards such as ANSI S12.60 for Acoustics in Schools and other rating systems such as LEED for Schools and CHPS provide guidance on performance/design needs for K‐12 schools. But what about postsecondary schools and especially those designed with reconfigurable architectural elements such as relocatable walls and raised floor system—can these be made to work? Initial results from this ongoing research will be discussed, including wall performance, ceiling/plenum effects, and sound system effects.

Fire tests were performed for various cable types and layouts under practical conditions. Surveys were carried out in a number of dataprocessing centers to determine a cable layout that meets the requirements of data-processing installations. The following tests were carried out: Flaming of cables outside the raised floor, flaming of cables under the raised floor and flaming of a cable support with cables under the raised floor. One litre of n-hexane, which was electrically ignited, served as ignition source. Thermocouples were used to measure the temperature course at many measuring points and the course of the fire was documented photographically. When the cables were flamed outside the space under the raised floor, the fire did not spread. When the cables were flamed under the raised floor, fire damage to the cables were more extensive, the cables spread the fire from the space under the raised floor into the test room. When only coaxial cables with improved fire-resistant characteristics were used, the extent of the damage was restricted to the area of the ignition vessel. The conclusions are briefly discussed with respect to fire protection measures.

Commercial straight-run broilers were reared on raised flooring in two experiments to study the effects on broiler performance and carcass quality of padded roosts and four raised floor types – wire, wood slats, plastic inserts over wire (Experiment 1) and plastic-coated expanded metal – and added dietary zinc bacitracin (Zb) at a level of 40 g per ton (909 kg) of feed (Experiment 2). In both experiments mean body weights, feed conversion ratios, percentages of mortality, and percentages of deformed legs were not significantly different among floor types. Floor types did not affect incidence of foot pad dermatitis or percent of body fat in Experiment 1 or folliculitis in Experiment 2. Feather soilage and folliculitis were significantly greater (P

A recent report, commissioned by Vigers Chartered Surveyors and carried out by the Building Performance Unit at Liverpool Polytechnic, has collected extensive evidence of defects in raised floors. One of its central themes is to provide guidelines for facilities managers wishing to obtain value for money from their raised floor installations. This article provides advice to managers who wish to extend the life cycle of raised floors in their care and in doing so reduce the scale of defects in use.

The paper includes the description of the functional features of the often used raised floor systems and the factors affecting their seismic performance. After describing some practical methods to support their frameworks and cabinets, considerations for the design of earthquake-resistant raised floor systems are suggested. Attention is given to the concept and design of the isolation system for the entire raised floor. Practical and economically feasible methods to provide such an isolation are recommended. The concept of a new nested isolation system and some preliminary test results indicate the practical merits of such a system.

Raised floor can be found in many traditional buildings throughout Indonesia, however this element currently disappears from Indonesia modern architecture. One of possible reason is limited study conducted on raised floor house, therefore the benefits of raised floor element; especially its application in tropical climatic is never exposed. Minahasa Traditional House is a traditional raised floor house that still exists today. This paper will investigate thermal comfort conditions particularly wind velocity inside of Minahasa Traditional House using Computational Fluid Dynamic (CFD) analysis. Simulation on several variations of openings and stilts height is conducted to measure its effectiveness in creating thermal comfort. The result of the study will become a reference for modern architect to design modern house that incorporate design features from vernacular architecture.

Access floor are raised floor systems consisting of modular panels supported by posts at a certain height to create a gap below the floor surface. Electrical wires and pipes can be placed inside the gap in order to avoid exposed installations and to simplify operations involving the inspection, repair, changing, or adding of system elements. This paper presents the results of the measurement campaign carried out on seven different access floor configurations, obtained by changing different floor elements: panels, surface finishes, damping materials under the posts base. Impact sound insulating properties of access floors combined with false ceilings were also tested and are reported in the paper. The tests were executed in two overlapping reverberating rooms available at the Acoustics Laboratory of the University of Perugia using the procedures given by ISO 140‐6 Standard. The results are expressed in terms of normalized sound impact pressure level Ln and of the corresponding single number index Ln,W.

In data centers, efficient cooling systems are required to both keep the energy consumption as low as possible and to fulfill the temperature requirements. The aim of this work is to numerically investigate the effects of using partial aisle containment between the server racks for hard and raised floor configurations. The computational fluid dynamics (CFD) software ANSYS CFX was used together with the Reynolds stress turbulence model to perform the simulations. Velocity measurements in a server room were used for validation. Boundary conditions and the load of each rack were also retrieved from the experimental facility, implying an uneven load between the racks. A combination of the performance metrics Rack Cooling Index (RCI), Return Temperature Index (RTI) and Capture Index (CI) were used to evaluate the performance of the cooling systems for two supply flow rates at a 100% and 50% of operating condition. Based on the combination of performance metrics, the airflow management was improved in the raised floor configurations. With the supply flow rate set to operating conditions, the RCI was 100% for both raised floor and hard floor setups. The top- or side-cover fully prevented recirculation for the raised floor configuration, while it reduced the recirculation for the hard floor configuration. However, the RTI was low, close to 40% in the hard floor case, indicating poor energy efficiency. With the supply flow rate decreasing with 50%, the RTI increased to above 80%. Recirculation of hot air was indicated for all the containments when the supply rate was 50%, but the values of RCI still indicated an acceptable performance of the cooling system.

The ‘biscuit tin’ floor box with its piano‐hinged lid has become the standard vehicle for connecting the cable which is fed below the raised floor to the desk equipment. Sometimes the unit has been specially developed — at what one can only presume to be considerable cost in the case of prestigious buildings like the Norman Foster Hong Kong & Shanghai Bank headquarters. In most installations, they are more mundane derivatives of the floor box which was housed in the floor screed and provided on a design module of something between 1.5 and 2m. Despite the greater flexibility supposedly inherent in a raised floor solution, the reality is that the floor box in the raised floor copes no better with the transition between the ‘secondary’ and the ‘tertiary’ wiring than it did in the screeded floor.