Low Flow Fume Hoods - Qualifying and Quantifying
the Current State-of-the-Art
David W. Frenze, PE
John W. Chan, M.S. REHYS, REA, CIH, University
of California, Irvine
Debbie M. Decker, University of California,
Davis
The Challenge:
The challenge was to qualify the viability of utilizing Low Flow/High
Performance Chemical Fume Hoods (LF/HP-CFH). As part of this qualification
process, four key data streams were simultaneously recorded to verify
that safe operating conditions were maintained. The team's objectives
are related to reducing air system capacity/energy use requirements.
The University of California, EH&S team, in conjunction with
third party consultants, endeavored to objectively evaluate the
current "state of the art" in LF/HP-CFH design offerings
currently available in the marketplace. In the course of the study,
we challenged widely published and marketed de-facto Chemical Fume
Hood (CFH) performance standards, to verify their ability to adequately
model common real-world CFH unit operations. Intended results included
comprehensive testing and reporting by an objective third party
testing agency that would substantiate a new and potentially more
useful protocol for LF/HP-CFH and CFH performance evaluation that
goes beyond traditional static ASHRAE 110 testing and that may better
support the Owner/User/Procurement stakeholders in the R&D marketplace.
The Study:
The University of California and their selected team first developed
a project approach and selected the appropriate dynamic testing
protocols after reviewing various published and recognized standards.
The use of ASHRAE 110 testing was also engaged for "test-to-fail"
testing in static mode and conventional tracer gas testing at "normal"
operating conditions to create a statistical backdrop to facilitate
evaluation of dynamic testing results. Sash positions evaluated
include 18 inches above work surface and full open sash.
Objective third party testing using veteran service providers with
NIST certified instrumentation and multi-channel data loggers began
in the field on two research sites. Data was collected for 26 conventional
CFHs. Subsequent testing in a controlled environment on a neutral
site added data sets for one conventional and five LF/HP-CFHs. Testing
personnel, testing equipment and man-as-manikin subject were identical
for each data set taken. Dynamic testing collected tracer gas concentration
data via human-as-maniken mounted sensors for "walk-bys"
and various "unit operations". Data reduction and evaluation
focuses on LF/HP-CFH performance and also compares and contrasts
LF/HP-CFH data with conventional CFH data.
Presentation of Findings and Materials:
Materials include dynamic testing protocol and graphical performance
data for all hood types (blinded with respect to manufacturer).
Findings on containment effectiveness will focus on LF/HP-CFH designs
but also will offer comparison and contrast to conventional CFH
performance. Discussion of findings will quantify potential annual
CFM throughput reductions and highlight variations in performance
based upon the selected control sequence (e.g. CAV, VAV with lower
CAV threshold, mid-range VAV with lower and upper CAV thresholds,
and two position CAV).
Labs21 Connection:
The underlying value of this presentation is to qualify the opportunities,
advantages and disadvantages of using LF/HP-CFHs in building designs
that are focused on improving building efficiency by "optimizing
supply air/exhaust air distribution and lowering energy consumption
for a lower initial central plant requirement and the coupled impact
or lowering life cycle cost.
Biographies:
David Frenze, PE, has over 20 years of business leadership,
senior project management, and mechanical engineering experience,
primarily in the chempharma, biopharma and university research marketplace.
He maintains that delivering value in design and construction begins
with dialogue-rich programming and planning sessions. Guiding principles
include communication, accountability, project pre-planning, defined
outcomes and genuine teamwork. Frenze, a strong believer in being
a life long learner as well as educator, maintains active membership
and committee involvement with ISPE, ASHRAE, PMI and Labs21. His
credentials include a BSME from The Ohio State University and the
LEED™ Accredited Professional Designer designation.
John Chan is the Manager of Industrial
Hygiene/Biosafety at the University of California, Irvine. Chan
has over 25 years of experience in Environmental Health and Safety
with an emphasis in industrial hygiene. He maintains a keen interest
in safety issues within the research laboratory environment and
was a key contributor to this most recent fume hood performance
study. John holds a Masters of Public Health degree with emphasis
in Occupational Health from the University of Southern California.
Debbie Decker is the campus Chemical
Hygiene Officer for the University of California, Davis. Decker
has over ten years of experience in health and safety at academic
institutions, focusing primarily on laboratory and chemical safety.
She is a Safety Advisor to the Veterinary School and lead trainer
for laboratory safety. She also liaisons on behalf of the Office
of Environmental Health and Safety with campus Architects and Engineers
for plan review of new construction and major renovation projects.
Her particular interest and expertise is in laboratory airflow control
systems. Prior to her academic experience, Decker worked as lead
chemist for an aerospace firm that manufactured explosive actuated
devices. She holds a degree in Chemistry from UCDavis and is an
active member of the Executive Board of the Division of Chemical
Health and Safety, American Chemical Safety.
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