ASHRAE Journal - October 2011 - 64

human perception of background noise for individuals exposed to: 1) discrete tones and 2) time-varying ﬂuctuations in background noise spectra. Phase I of the study will ﬁrst determine the effect of exposure time and test type. Phase II will then use the optimal exposure time and productivity test to complete the main study. The goal is to determine how the current noise criteria systems correlate to productivity and psychoacoustic perception under the variety of systems-induced indoor noise situations. Based on the results, suggestions or modiﬁcations to noise criteria systems may be proposed to allow the rating systems to account better for the subjective results.

The objective is to develop, test, validate and establish a recommended minimum Pressure Differential Table (PD Table) which lists a “group” of pressure differential values as criteria for various conditions. This table is intended to replace the existing “single” pressure differential criterion. The establishment of the PD Table should be based on the conclusions of the experiment identiﬁed under the section of “SCOPE” rather than educated guesses. This research must be conducted in a manner such that the reduction of pressure differential in the clean room will not result in an increase of particles.

1327-RP Flow Regime and Pressure Drop Determination for Two-Phase Ammonia Upward Flow in Various Riser Sizes
April 2007 – June 2012; Teknologisk Institut (DTI); Principal Investigator, Thomas Lund; TC 10.3, Refrigerant Piping

1345-RP

Waterside Fouling Performance of Brazed-Plate Type Condensers in Cooling Tower Applications

April 2008 – October 2011; Oklahoma State University; Principal Investigator, Lorenzo Cremaschi; TC 8.5, Liquid-to-Refrigerant Heat Transfer; AHRTI $47,000 co-funder

This ASHRAE research project will have a signiﬁcant worldwide energy impact and an annual monetary savings that is far in excess of the project cost. The advancement to the state of the art will be the publication in the ASHRAE handbooks a set of design curves that will deﬁne the optimal suction riser velocity for a range of pipe diameters and temperatures. This information will be the only data of its type available in the public domain at these pipe size ranges and with ammonia. It will be used by industrial refrigeration system design engineers and plant operating engineers worldwide. The objective of this research project is to determine the minimum vapor velocity required to sustain vertical upward ﬂow of liquid anhydrous ammonia when transported by vapor anhydrous ammonia in the same pipe. This velocity shall be determined for a range of pipe diameters, overfeed rates, and temperatures. The pressure drop per foot of pipe as a function of velocity, temperature, and overfeed rate will also be determined.

1335-RP Effects of Typical Inlet Conditions on Air Outlet Performance

April 2009 – June 2011 (P); University Nevada – Las Vegas; Principal Investigator, Brian J. Landsberger; TC 5.3, Room Air Distribution

The objective of this project is to develop guidelines that will relate manufacturers’ air outlet cataloged data that has been obtained using ASHRAE Standard 70 to ﬁeld installed “application conditions.” The intent of this project is to obtain base performance data using ASHRAE standard 70 and to obtain and compare application test data of diffusers with “real life” inlet conditions. Correction factors are to be obtained for inlet conditions that represent actual installed conditions including elbows and close coupling and volume control dampers.

1339-RP Selection of Desiccant Equipment at Altitude

April 2010 – August 2011; Mississippi State University; Principal Investigator, Nelson Fumo; TC 8.12, Desiccant Dehumidification Equipment and Components

The results of this project would have immediate usefulness to consulting engineers and anyone else involved in the selection of desiccant based equipment for non-standard altitudes. Without proven procedures to follow, the industry practice has been to add safety factors to sea level selections roughly based on air density changes. Of the 4422 locations listed in Chapter 28, over 1200 (27%) are at elevations above 1000 ft and nearly 700 (15%) above 2000 ft. Preliminary data shows that this could result in signiﬁcant over sizing of equipment and excessive operating costs. It is estimated that 30% of the desiccant equipment sold for operation above 2000 ft is now oversized which represents more than $5 million in US equipment sales and nearly $15 million world wide. The objective of this project is to develop and to validate a set of procedures (guidelines) to be used to restate the catalog (sea level) performance of a desiccant dehumidiﬁer that will operate at altitude. The outcomes of the project should be used to predict the performance of desiccant equipment at altitude and to inform designers, building owners and managers, and equipment operators as to: The expected moisture removal capacity (MRC) performance of a standard desiccant unit as a function of altitude. Equipment design features and sizing issues (regeneration heat capacity, pressure drop, air temperature rise, fan selection).

The fouling characteristics and the ability to clean brazed-plate heat exchangers are not generally known - only basic guidelines for chemical cleaning are available from the brazed plate heat exchanger manufacturers. However the effectiveness of this cleaning method is undocumented for AC&R applications and in some cases the cleaning is not possible because of installation constraints. Thus, for critical service applications, brazed-plate heat exchangers are less-likely to be speciﬁed than other heat exchangers for which the fouling characteristics are better known. For high-pressure refrigerant applications, such as with R-410A which is gaining widespread industry acceptance, brazed-plate heat exchangers generally offer lower ﬁrst-costs than other heat exchanger types, require smaller refrigerant charges, and reduce overall system footprints than tubular types. This is because the internal structural design of the brazed-plate type heat exchangers allows for the use of thinner metal sections than in tubular heat exchanger designs. The resulting smaller system package sizes then require less mechanical room ﬂoor space and offer reduced ﬂoor and roof loadings in comparison to system packages that utilize tubular type heat exchangers for these applications. Successful determination of the fouling characteristics of brazed plate heat exchangers and the subsequent incorporation of the results into the ASHRAE Handbook and ARI Guideline E will allow AC&R system designers to properly select these heat exchangers for use in less-than-ideal ﬂuid situations and to provide proper maintenance recommendations. This will lead to more ﬂexibility in system design with high-pressure refrigerants, lower overall unit ﬁrst cost and reduced condenser refrigerant operating charges on the order of 50%. The speciﬁc objectives of this project are as follows: •	 Quantify the difference (if any) in fouling rates between brazed plate heat exchangers and tube types; •	 Experimental determination of fouling on brazed plate heat exchangers using simulated cooling tower water; •	 Correlation of fouling data with water quality for brazed plate heat exchangers; •	 Correlation of fouling data with plate aspect ratio, chevron design & ﬂux within the scope of this project; and •	 Update information contained in ASHRAE Handbook, HVAC Systems & Equipment Volume, Chapter 35 – Condensers and possibly ARI Guideline E– Fouling Factors: A Survey of Their Application in Today’s Air Conditioning and Refrigeration Industry.

1353-RP

Stability and Accuracy of VAV Box Control at Low Flows

September 2007 – February 2012; Drexel University; Principal Investigator, Jin Wen; TC 1.4, Control Theory and Application

1344-RP Cleanroom Pressurization Strategy Update – Quantification and Validation of Minimum Pressure Differentials for Basic
Configurations and Applications
April 2009 – January 2012 (P); Engsysco, Inc.; Principal Investigator, Wei Sun; TC 9.11, Clean Spaces

Enhancement of cleanroom pressurization technology requires multi-discipline efforts with applications of the latest techniques in airborne particle counting, air leakage, room ﬂow/pressure simulation, network ﬂow modeling, CFD, ﬂow visualization, precision pressure and ﬂow measurements and HVAC controls, these requirements make ASHRAE in a unique position with necessary expertise. The potential results from this research project will affect a broad range of facilities and applications including pharmaceuticals, food processing, healthcare, museums and others. The industry currently has limited scientiﬁc research in this area, which is causing various codes and standards to reference incomplete or inaccurate data in order to have something as a value. The recommendations from the potential results will not only beneﬁt cleanroom engineers in design, facilities, validation and manufacturing ﬁelds, but also provide a good reference to engineers in industrial ventilation, bio-safety laboratory, healthcare, smoke management and other related areas. ASHRAE will deﬁnitely beneﬁt from the potential results for the future handbook inclusion, revision, design guides, and related code updates.

The reliable control of airﬂow rates in VAV systems is important for a number of reasons, most signiﬁcantly: acoustics, ventilation, energy management and occupant comfort. Stability and accuracy of VAV boxes rely on the performance of four main components: the velocity pressure sensor (traditionally provided with the box by the box manufacturer or the controls vendor); the zone controller (typically provided by the controls vendor); the box damper or air valve (integral to the terminal unit), and the modulating actuator (integral with the controller or ﬁeld installed). The objectives of this project are to isolate, evaluate, and relate the performance of these components individually and as a “system” to a range of typical operating conditions. Other project objectives include: •	 Develop practical recommendations for engineers and contractors in order to successfully achieve low air ﬂow control; •	 Recommend methods of test (MOTs) for rating air ﬂow sensors at low ﬂow (e.g., k-factor) and for controller minimum signal; and •	 Perform ﬁeld test to validate low ﬂow stability of installed VAV boxes.

1356-RP

Methodology to Measure Thermal Performance of Pipe Insulation at Below-Ambient Temperatures

August 2008 – January 2012 (P); Oklahoma State University; Principal Investigator, Lorenzo Cremaschi; TC 1.8, Mechanical Insulation Systems

The overall objective of the proposed research is to design an experimental apparatus capable of measuring the effective thermal conductivity of pipe insulation systems at below-ambient temperature. The end loss, energy metering, temperature measurement, equilibration criteria, and other operational issues will be conform to the requirements of Standard ASTM C 335 and the design will be discussed with the Project Monitoring Subcommittee (PMS) for approval prior to the initiation of work on any subsequent task. The PIs will produce a set of shop drawings and a parts list for the test apparatus. Certain physical limitations are proposed for this apparatus. Firstly, the apparatus will

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ASHRAE Journal

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October 2011
ASHRAE Journal - October 2011

Table of Contents for the Digital Edition of ASHRAE Journal - October 2011
