where it’s cooled using a combination of
air, previously cooled effluent and a minimal amount of cold water before being
discharged. Premium water-conservation
systems that utilize a building’s recirculated chilled water can lower consumption
by up to 99%. Consumption data from
Consolidated Sterilizer Systems, Boston,
Mass., shows labs can save $100,000 in water
costs over the life a premium sterilizer, with
a two-year typical payback period for the
Superior insulation reduces heat loss to
the room from sterilizers. This equipment
can also be supplied with a calendar feature that shuts off steam supply when the
sterilizer is idle.
COLD STORAGE AND OTHER EQUIPMENT
Water-cooled ice machines run quietly
and are more efficient than air-cooled
models. Water-cooled machines have
two separate water lines: one feeds the
ice-making equipment and the other
removes heat from the refrigerant. Closed-loop systems re-use the building’s chilled
water that cools the equipment.
There is currently no Energy Star rating
for lab-grade refrigerators, freezers and
ultra-low freezers, but the EPA is working
to develop specifications and test methods
for this type of equipment.
For maximum efficiency, choose the
appropriate cabinet size and tempera-
Sustainable lab equipment:
What’s new, what’s possible
continued from page 6
Analysis of water-cooled versus air-cooled compressor technology. Image: SmithGroup JJR
ture setting for cold storage of samples.
Lowering the ambient room temperature
has also been shown to have a significant linear impact (about 4% per degree
Celsius) on energy usage.
Variable speed drive compressors adapt
to a lab’s usage patterns. By maintaining
temperature at the lowest compressor
speed, then increasing speed to restore
temperature quickly when the door is
opened, this technology provides greater
energy efficiency and improved sample
security. Water-cooled compressors can
save up to 17% in energy consumption.
Global Cooling Inc., Athens, Ohio, manufactures Stirling Ultracold freezers, which
utilize free-piston Stirling cooling engines
based on technology originally developed
in the 1800s. According to the company,
these freezers use 50% less power, generate 50% less heat and have more storage
capacity per square foot of floor space than
freezers that use conventional cascade
(compressor) cooling systems, for a lifetime cost that’s 30% less than conventional
Thermoelectric incubators use 75% less
energy than compressor-based refrigerated
incubators, and can reduce room air conditioning loads by 75%, as well. Compressor
efficiency can be improved by installing
electronically commutated evaporator fan
motors in place of standard motors and using
LED door lights in place of fluorescents.
Bottom-mounted evaporative compressors
use the heat of the compressor to evaporate
condensate collected on the refrigeration
coils. This design is more efficient and quieter than top-mounted compressors.
Automatic faucets may reduce water
consumption by discouraging continuous
water usage, but water savings are difficult
to measure because individual usage habits differ greatly. Unless automatic faucets
also feature water-saving aerators, they
don’t qualify as water-reduction measures
under the various green certifications.
These faucets are appropriate for some lab
activities, like hand washing, but not others,
like glassware washing. Consult with users
for suitable locations for faucets. Acceptable
flow rates range from 1.5 to 2. 2 gal/min.
There are t wo types of flow control devices. Aerators add air to the water, making the
flow feel “lighter.” Laminar flow devices
produce a stream comprised only of water,
and tend to make the flow feel “heavier,” for a
perceived higher flow rate to users.
Safety is the first priority in any lab.
Beyond that, efficiency is a matter of balancing user requirements, scientific programs and sustainability goals. Ultimately,
it all has to work. But with the available
technology, a 10% or more reduction in
plug loads is realistic, even in the ener-gy-intensive lab environment.
Victor J. Cardona, AIA, VP and director of
lab planning, and Christopher P. Vanneste,
Associate, are with SmithGroupJJR (www.
smithgroupJJR.com), a 900-person architecture, engineering, interiors and planning firm
with 10 offices worldwide. SmithGroupJJR specializes in the science and technology, healthcare, learning and workplace markets.