Basic Documentation

Page 2 of 14 Siemens Industry, Inc.
Document No. 149-488
The American Society of Heating, Refrigeration and
Air-Conditio
ning Engineers (ASHRAE) drafted a
Standard for the Design of High-Performance Green
Buildings Except Low-Rise Residential Buildings. (At
the time of this publication, ASHRAE’s document is
a draft, not an approved standard.) In contrast to the
rating systems that let a design team select which
measures to employ, this document specifies
requirements. It is intended for adoption into building
codes. The influence of LEED on the proposed
standard is clear. The five subject areas in the draft
line up closely with the five categories of LEED
credits.
Some institutions have digested the available
guidelines and drafted their own sustainability policy.
The California State University system is an
example. Their policy defines sustainable design
with a set of seven attributes, including efficient use
of water and energy, optimized indoor environment
and procedures to monitor performance.
2
Others use the LEED guide, but choose not to apply
for certification. Ultimately, it’s up to a building owner
or a design team to decide how they will apply the
published guidance.
The following pages refer to credits and
prerequisites of the Labs21 scorecard, to LEED-NC
and to requirements of the proposed ASHRAE
standard.
Innovation in Design and
Operation
The USGBC created a general category of credits in
addition to the five more specific categories.
Sometimes a team executes an idea that doesn’t fit
in the scorecard, but contributes to sustainability.
This technology report suggests a few of them. In
such cases, points may be awarded for Innovation
and Design (ID).
Energy and Atmosphere
HVAC systems serving laboratories often use a
great deal more energy than systems for other kinds
of buildings. That’s because laboratories are
ventilated at high rates, typically with 100% outside
air. This means we need energy to move the air into
2. The California State University, Executive Order No. 987,
"Policy Statement on Energy Conservation, Sustainability
Building Practices, and Physical Plant Management for the
California State University" (August 2, 2006).
the room, energy to pull it out, and energy to heat,
cool, humidify or dehumidify the outdoor air to
conditions required in the lab.
The Labs21 team communicates the scale of this
problem by comparing the energy needed to operate
one fume hood (6-foot, vertical sash, vertical hood)
to the consumption of three single-family homes.
3
There are engineering strategies to address each of
those energy loads; you can increase the efficiency
of the air supply and exhaust systems; you can
recover heat to reduce the air conditioning load.
These are important and useful, but the most
important strategy addresses both loads directly:
airflow reduction!
Reducing Airflow
In a typical chemistry or biology laboratory, the
airflow rate for the room is set by one of three
drivers:
 The exhaust devices in the room
 The cooling load
 Ventilation needed to dilute and remove
contaminants in the air
In some labs, one of these drivers is always in
control. In others, it changes dynamically with
activity in the space.
A Green Team, seeking to save energy usually has
to pay attention to all three drivers. Effective action
against one load is likely to push another one into
the critical position. At that point, the team needs to
shift the focus to continue its progress.
Each of the following airflow reduction strategies
attack one driver. A successful team is likely to need
more than one tactic.
VAV and Occupancy
Historically, many laboratories were ventilated at a
constant rate, all day, everyday. This practice is
almost completely obsolete in new designs (there
are special exceptions), but there are still many old
facilities that have not been upgraded.
There are two approaches to dynamic airflow
reduction. One is called Variable Air Volume (VAV)
because it gradually adjusts airflow rates up and
3. Evan Mills and Dale Sartor, "Energy Use and Savings
Potential for Laboratory Fume Hoods", Energy Volume 30,
Issue 10 (2005): 1859–1864.