Midwest HVAC News
Air Curtains and Other
Green Tech Makes Chicago Supermarket Chain One of Nation's
Pete's Fresh Market's progressive energy strategy includes air
curtains, outdoor air dehumidification, CO2 refrigeration and
CHICAGO--Pete's Fresh Market is one of the greenest supermarket
retailers in the U.S., but there's one difference between the
Chicago-based nine-store operation's green mission and other chains.
Pete's records energy data and uses only equipment with a proven
energy efficiency track record at previous stores.
Consequently, each new store becomes more energy efficient than its
predecessor. For example, the new 62,000-square-foot, suburban
Chicago Oakbrook Terrace, Ill. store uses air curtains, dedicated
outdoor air dehumidification, high-efficiency rooftop HVAC units,
CO2 refrigeration systems, a green roof and energy recovery
equipment that were successfully tested in previous stores.
For Eugene Grzynkowicz, senior project development executive of
Pete's Fresh Market, going green is environmental, but it is also a
long term solution to reducing supermarket operational costs. "With
all the federal money available and utility incentives, we're trying
to take advantage of today's green technology, as long as it works,"
Air curtains, for example, appear on all nine of Pete's stores. Air
curtains are best known as chemical-free sanitation alternatives to
eliminating flying insect infiltration through foodservice back
entrance pedestrian and shipping doors, especially in California
which has a state health code mandating them.
Like many supermarkets, Pete's has back entrance air curtains, but
takes the technology one step further. The Oakbrook Terrace store
has Mark II Series air curtains manufactured by Berner
International, New Castle, Pa., above the front entrance's automatic
double sliding doors on an entry and exit vestibules.
Grzynkowicz says the air curtains target flying insect infiltration,
but are equally important in conserving energy and keeping employees
and customers comfortable at check-out during the winter months. The
air curtains keep indoor and outdoor environments separate by
"sealing" the doorways with a strong airstream, especially since all
vestibules become energy losing wind tunnels when both doors open
simultaneously. Furthermore, nearby employees and customers get
supplemental heating with an onboard, thermostatically-controlled
20-kW electric heating coil.
Installed by mechanical contractor, B and N Sheet Metal Co.,
Chicago, the three-speed air curtains include an onboard
programmable control package. When the door opens, a low-voltage
magnetic read switch simultaneously activates the air curtain's
highest programmed speed and electric heater, the latter only if
needed for surrounding indoor air comfort. After closing, the
control package automatically switches the motor to a low speed and
the thermostat delays the shutoff of the air curtain and electric
heater shutoff until the surrounding area's set-point temperature is
continues below ↓
Berner's custom metal shop also extended the front entrance's
six-foot-wide air curtains with a three-foot-long false panel on
each end to span past the door opening and reach each end of the
12-foot-wide aluminum and glass entrance frame, according to
Scott Williamson, vice president, R. Williamson & Associates,
LLC, a Skokie, Ill.-based manufacturer's representative that
specializes in exhaust fans, air handlers and air curtains. The
air curtains are ceiling-hung with thin diameter aircraft cables
that virtually disappear visually from a distance. "Pete's is a
very high-end space and the air curtains are custom-designed and
installed to maintain that appearance," Williamson said.
Besides air curtains, Pete's is saving energy with dedicated
outdoor air dehumidifiers by Munters, Selma, Texas, to reduce
the air conditioning loads, equipment sizes and number of
rooftop units on each store.
Pete's also recovers heat from its 22-foot-high ceilings with
1,600-cfm space heaters by Modine Manufacturing, Racine, Wis.,
that supplement 55,000-Btu modulating condensing boilers by
Buderus--div. of Bosch Group, Londonderry, N.H., to warm-up the
frozen food and dairy aisles for customer and employee air
comfort. The space heaters and boilers were installed by United
Mechanical, Bensenville, Ill.
Pete's other green measures include Air Pear fan systems by
Airius LLC, Longmont, Colo.; refrigeration rack and HVAC
refrigerant management with UltraSite Control System by Emerson
Climate Technologies, St. Louis, Mo.; cold cathode lighting;
shade trees for asphalt coverage; hot water reclaim; sensor
light controls; and recycled building materials.
Now with several stores with energy-saving equipment track
records, Pete's plans to combine many of those technologies in
its 10th store, which is scheduled for late 2013 completion.
It's destined for a Leadership in Energy and Environmental
Design (LEED®) certification and will be one of the most energy
efficient supermarkets in the country.
SIDEBAR: Specify Air Curtains for Velocity, Volume and
Velocity, volume and uniformity work together to create the
ideal air curtain performance, therefore relying on only one or
two of three could skew performance results.
Velocity: To properly design an air curtain installation, the airstream must hit the floor with enough velocity to create a
split. The split, which creates stability, strength and
direction for the air entrained on each side of the airstream,
should occur right at the doorway’s threshold. An installation
with a weak airstream, one that barely splits for example, is
only viable for applications involving temperature differential
without wind, such as internal doorways. They’re capable of
stopping infiltration or cross contamination of environments due
to airflow caused by the temperature differential, but they
become ineffective once wind is introduced. Few external
doorways are not affected by wind loads.
Volume: Volume, on the other hand, is the building block that
allows a properly designed and pressurized discharge plenum to
generate a high velocity laminar jet stream. The taller the
opening, the more volume that is required to generate a thicker,
higher velocity airstream to resist wind loads of four to five
mph. Obviously an air curtain for a fast food restaurant’s
drive-through window doesn’t need as strong a volume as a
16-foot high door in a shipping area. Once an air curtain
activates and creates a split, it creates a “skin” over the
building’s volume of indoor air and uses this internal pressure
to resist wind. The split then rolls the entrained conditioned
and unconditioned air back to their respective areas.
Uniformity: Another important factor to consider in air curtain
performance and selection is uniformity, which only impacts the airstream effectiveness when it drops below 75-percent. An air
curtain that focuses too much energy on generating a high
uniformity loses velocity, therefore reducing its effective wind
About Berner: Berner International Corporation is North
America's original air curtain manufacturer since 1956 and
remains a leader in the air door/air curtain equipment
manufacturing industry. Berner is a member of the U.S. Green
Building Council (USGBC), The Green Building Alliance (GBA), the
Air Movement & Control Association (AMCA), the American Society
of Heating, Refrigerating & Air Conditioning Engineers (ASHRAE)
and also a certified Women’s Business Enterprise National
Council member (WBENC). For more information on Berner and its
products, please call (724)-658-3551 x403 or visit