The final reports for the following research projects are
available for free for ASHRAE members. Visit www.ashrae.org/research and log in
to gain access. The ASHRAE Transactions papers are available for $5 for
ASHRAE members at www.ashrae.org/bookstore.
Variable air volume (VAV) systems with direct digital
controllers (DDC) have been widely adopted in HVAC systems as they can provide
better energy efficiency and occupant comfort. However, engineers do not have
the complete set of tools to determine how low of a flow VAV boxes can stably
control. This low flow instability can result in problems including under
ventilation, uneven control, reduced damper and operator life, and energy
waste. 1353-RP, “Stability and Accuracy of VAV Box Control at Low Flows,”
studied the source of these VAV inaccuracy and instability to better understand
and design for the low flow issue. Two papers on this project have been
submitted for future publication in ASHRAE HVAC&R Research Journal.
1353-RP, “Stability and Accuracy of VAV Box Control at Low Flows,” was
sponsored by TC 1.4, Control Theory and Application. The principal investigator
was Dr. Jin Wen with Drexel University.
1493-RP, “CFD Shootout Contest – Predication of Duct
Fitting Losses,” involved a contest to determine duct fitting loss coefficients
using a commercially available CFD modeling tool. The research evaluated the feasibility
and accuracy of using CFD techniques to numerically determine the loss
coefficients for duct fittings. Results are presented in the report. Technical
papers on this project were published in ASHRAE Transactions (Vol. 119
(2), DE-13-030) and HVAC&R Research Journal (Vol. 18(6), Dec. 2012)
are now available. 1493-RP, “CFD Shootout Contest—Predication of Duct Fitting
Losses,” was sponsored by TC 5.2, Duct Design. The principal investigators were
Dr. Ahmad Sleiti with University of North Carolina-Charlotte and Dr. John Zhai
with the University of Colorado.
1522-RP, “Establishment of Design Procedures to Predict
Room Airflow Requirements in Partially Mixed Room Air Distribution Systems,”
developed a design guideline and design tool with graphical interface for
Underfloor Air Distribution (UFAD) systems to help predict thermal
stratification provided by these partially mixed room air distribution systems.
These tools, described in the final report, can be used to estimate supply
airflow requirements of UFAD systems not currently available in the UFAD Guide:
Design, Construction and Operation of Underfloor Air Distribution Systems or
the ASHRAE Handbook. Engineers will be able to have a quick and reasonable
estimation of airflow and room temperature using this design tool. Two
technical papers were published in ASHRAE HVAC&R Research Journal (Vol.
18(6), Dec. 2012) and are now available. 1522-RP, “Establishment of Design
Procedures to Predict Room Airflow Requirements in Partially Mixed Room Air
Distribution Systems,” was sponsored by TC 5.3, Room Air Distribution. The
principal investigator was Zheng Jiang with Building Energy and Environmental
1583-RP, “Assessment of Burning Velocity Test Methods,”
compared the two burning velocity test methods referenced in ASHRAE Standard 34
to determine if they were appropriate for the mildly flammable refrigerants
classified as “subclass 2L.” The two flammability tests (vertical-tube &
Schlieren) were originally developed for highly flammable fuels and not
intended to be applied to mildly flammable refrigerants. The research evaluated
the precision and accuracy of each test method and to seek potential for test
method simplification and cost reductions without sacrificing quality. The
results of the research project and proposed changes to the test methods for 2L
refrigerants are described in the final report. Two technical papers on this
project were published in ASHRAE Transactions (Vol. 119 (2), DE-13-022,
DE-13-023) and are now available.
1583-RP, “Assessment of Burning Velocity Test Methods,” was
sponsored by TC 3.1, Refrigerants and Secondary Coolants. The principal
investigator was Dr. Kenji Takizawa with National Institute of Advanced
Industrial Science Technology.
ASHRAE Standard 15 includes a formula for mechanical
ventilation required to exhaust refrigerant from a refrigeration machinery room
in the event of a leak. Major model building codes have adopted ventilation
requirements based on the equation in this Standard which only considers the
mass of the refrigerant in the room. This equation dates back to the 1930s and
the engineering basis is not clear. 1448-RP, “Ventilation Requirements for
Refrigerating Machinery Rooms,” developed a new exhaust ventilation calculation
based on factors including the size of the space, the refrigerant mass,
refrigerant properties, accident scenarios and additional factors. A technical
paper on this project was published in ASHRAE Transactions (Vol. 118
(2), SA-12-014) and is now available. 1448-RP, “Ventilation Requirements for
Refrigerating Machinery Rooms,” was sponsored by TC 4.3, Ventilation
Requirements and Infiltration. The principal investigator was Dr. Ron Petersen
with CPP Inc.
Data to help designers accurately predicting the
aerodynamic and acoustical response of centrifugal fans with airfoil (AF) and
backward inclined (BI) blades to common appurtenances and cabinet design at the
fan inlet is limited. To better understand the real world performance of these
fans, 1216-RP, “Inlet Installation Effects on Bi/Airfoil Centrifugal Fans, Air
and Sound,” studied the effect of various appurtenances including various
bearings, bearing supports, inlet guide vanes at various angular positions,
inlet boxes, inlet duct elbows at various angles and distances from the inlet,
inlet duct contractions, walls perpendicular to the fan axis at various
distances from the inlet, cabinet enclosures of various configurations, flex
duct connections, inlet and belt guards and bird screens. The results will
serve as a guide to those designing or specifying AF and BI fan systems for
office and commercial buildings. A technical paper has been submitted for
future publication in ASHRAE Transactions. 1216-RP, “Inlet Installation Effects
on Bi/Airfoil Centrifugal Fans, Air and Sound,” was sponsored by TC 5.1, Fans.
The principal investigators were Mr. Mark Stevens with AMCA and Mr. Alain
Guedel with CETIAT.
devices (TDD) have emerged as alternative to conventional skylights. However,
prediction of the thermal and lighting performance of TDDs is difficult as reliable
and accurate calculation methods and design tools are not available. Such tools
would allow designers to predict the energy performance of installed TDDs, to
show compliance with building energy codes, and to rate existing and/or
innovative products. 1415-RP, “Thermal and Lighting Performance Metrics of
Tubular Daylighting Devices,” presents some computational algorithms and
metrics for the lighting and thermal performance of TDDs to fill this need.
Technical papers on this project were published in ASHRAE Transactions
(Vol. 117(2), MT-11-021) and HVAC&R Research Journal (Vol. 19(1),
Jan.2013 & Vol. 19(3), Apr.2013) and are now available. 1415-RP, “Thermal
and Lighting Performance Metrics of Tubular Daylighting Devices,” was sponsored
by TC 4.5, Fenestration. The principal investigator was Dr. Aziz Laouadi with
Comprehensive risk assessments of 2L refrigerants are
needed to evaluate their use in residential and small commercial applications.
1580-RP, “Study of Parameters for Risk Assessment of 2L Flammable Refrigerants
in Residential Air Conditioning and Small Commercial Refrigeration
Applications,” performed CFD simulations, concentration mapping tests, and
ignition tests to determine leak scenarios for selected 2L refrigerants that
may result in flammable concentrations. 1580-RP, “Study of Parameters for Risk
Assessment of 2L Flammable Refrigerants in Residential Air Conditioning and
Small Commercial Refrigeration Applications,” was sponsored by TC 3.1,
Refrigerants and Secondary Coolants. The principal investigator was William
Goetzler with Navigant Consulting.
ASHRAE advances the arts and sciences of heating, ventilation, air conditioning and refrigeration to serve humanity and promote a sustainable world. With more than 53,000 members from over 132 nations, ASHRAE is a diverse organization representing building system design and industrial processes professionals around the world.