ASHRAE Journal - October 2010 - 57

mental set up was funded by the AIR Distribution Institute and can be used directly for the ASHRAE project. This data will be used for the Fundamentals Handbook and to extend ASHRAE’s Duct Fitting Data Base (printed and electronic). Computational Fluid Dynamics, using Fluent, calculations and graphics are part of the ADI project and will be made available to ASHRAE.

1335-RP	 Effects of Typical Inlet Conditions on Air Outlet Performance
April	1,	2009	–	March 31, 2011; 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	–	March	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 feet and nearly 700 (15%) above 2000 feet. 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 feet 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: a. The expected moisture removal capacity (MRC) performance of a standard desiccant unit as a function of altitude. b. Equipment design features and sizing issues (regeneration heat capacity, pressure drop, air temperature rise, fan selection).

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-thanideal 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: a. quantify the difference (if any) in fouling rates between brazed plate heat exchangers and tube types b. experimental determination of fouling on brazed plate heat exchangers using simulated cooling tower water c. correlation of fouling data with water quality for brazed plate heat exchangers d. correlation of fouling data with plate aspect ratio, chevron design & flux within the scope of this project e. 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 Flooded Corrugated Plate 1352-RP	 Evaporation inAmmonia/Miscible Oil Heat Exchangers With Ammonia and
September	2006	–	August	2010; Ghulam Ishaq Khan Institute; Principal	Investigator, Sultan Khan; TC	 1.3,	Heat Transfer and Fluid Flow; $10,000 co-funder	International Institute of Ammonia Refrigeration (IIAR)

1344-RP	 and Validation of Minimum Pressure Differentials for Basic
Configurations and Applications
April	2009	–	March	2011; Engsysco, Inc.; Principal	Investigator, Wei Sun; TC	9.11,	Clean Spaces

Cleanroom Pressurization Strategy Update – Quantification

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 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.

The issues of ozone depletion and global warming have propelled interest in the use of natural refrigerants in the air conditioning and refrigeration industry. For decades, ammonia has played a prominent role in the industry, particularly in the field of food, beverage, and marine refrigeration. The United States food industry mainly uses ammonia as the refrigerant of choice. Ammonia is natural, ozone-friendly, inexpensive, and has four to six fold higher heat transfer characteristics when compared to halocarbon refrigerants. However, its toxicity seems to act as a stumbling block for its wider use. This aspect could be addressed by utilizing compact heat transfer equipment that can result in an order of magnitude reduction in the operating charge. In the last decade, plate heat exchangers have rapidly replaced the conventional shell and tube evaporators. However, there is very limited information available in the open literature regarding the use of plate heat exchangers as evaporators. Engineers, designers, and end users have no information available with respect to the thermal-hydraulic issues of using plate heat exchangers as evaporators. The basic objective of this project will be to perform evaporation heat transfer and pressure drop tests on plate-type heat exchangers, with ammonia and ammonia/miscible oil mixtures at various temperature and pressure conditions of interest to the AC&R industry. The tests will not be manufacturer-specific, but rather geometry-specific so that universal correlations and/or charts can be developed for the general benefit of the stakeholders. The investigator is expected to present the results of the study in a manner that clearly and quantitatively shows the enhancement factors achieved by plate exchangers when compared to conventional evaporators.

1353-RP	 Stability and Accuracy of VAV Box Control at Low Flows

September	2007	–	February	2011; Drexel University; Principal	Investigator, Jin Wen; TC	1.4, Control Theory and Application

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

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. • Perform field test to validate low flow stability of installed VAV boxes.

The fouling characteristics and cleanability of 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

1356-RP	 Methodology to Measure Thermal Performance of Pipe Insulation at Below-Ambient Temperatures
August	2008	–	July	2011; 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

October 2010

ASHRAE Journal

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ASHRAE Journal - October 2010

Table of Contents for the Digital Edition of ASHRAE Journal - October 2010
