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| A 16% savings in electricity was
experienced by a Sheetz Inc. convenience store in Altoona, Pa., as measured by local power
company GPU Energy, from the use of a new refrigeration system applying a
"unique" counter flow defrost design. The measured savings were on top of an
approximately 30% additional power savings already being realized from other new
refrigeration system design features.
All those savings were in addition to improved freezer dryness and temperature
stability advantages gained from the extremely rapid defrost of the new system. |
"This is certainly the refrigeration
system equipment we’ll in all of our new stores and retrofits," said George
(Skip) Trostle, equipment buyer and installation supervisor for Sheetz. "This is
the driest freezer we ever had, it holds temperatures to closer tolerances, and saves us
money to boot."
"Sierra" refrigeration systems, patented and available only from Russell, are
designed specifically for the ½ through 5 hp needs of convenience stores and fast food
outlets. The systems move the function of the receiver from a separate tank to the
condenser coil. This provides a larger condensing surface, saving approximately 10% in
power consumption, the company says. |
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| COMMERCIAL REFRIGERATION The
system design also requires 20% less refrigerant, which provides one-time savings of
roughly $180. And since the system design also uses floating head technology, it can offer
up to 30% additional power savings as the outside ambient temperature drops.
With the various valves, controls, and accessories factory installed and no need for
electric heater wiring, contractors save time and approximately $150 on equipment
installation, the company says.
The design may even offer additional savings through a need for a slightly smaller-hp
system for the identical application.
STILL GREATER EFFICENCIES
Russells new "High Sierra" design adds a counterflow defrost to the Sierra
design. This variation on a two-pipe, hot gas defrost requires much less power than
traditional electric defrost, and is only possible because of the basic Sierra design, the
company says. |
With no melting frost falling on heating
elements, the design also eliminates steaming, thus helping avoid the unsafe build-ups
common in many freezers. Since the defrost is extremely rapid, taking 3 to 5 min in most
applications, less heat is introduced into the freezer and temperatures are maintained
very closely.
Walk-in freezer in the Sheetz convience store that's experiencing the many
savings of Russell's High Sierra
The new counter-flow defrost requires only the standard liquid and suction lines, with
no special piping or control lines, so it’s simpler to install.
The advantages of a dryer freezer and close maintenance of product temperature may,
together, be of greater value than the savings.
All together, based on a conservative 10-year equipment life,
Russell computes that the savings of High Sierra systems can actually pay for themselves. |
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George (Skip) Trostle, equipment buyer and installation
supervisor, Sheetz Inc., says, "Defrost is so quick it's the way we're going in the
future."
GPU energy figures show that the Beal Ave. Sheetz store freezer used 241.82 kWh during the
study, while the Galleria store cooler used 288.96, for a savings of 16%, or $29.44 in a
month. This study compared a 3 hp High Sierra system in the Beal store with a 3 hp Sierra
system in the Galleria store.The monitoring also showed a significantly lower peak
amperage (61 to 245) with accompanying advantages. The stores are both located in the
Altoona area, so ambient temperature differences were minimal.
QUICK DEFROST
"This freezer goes in and out of defrost so quick, the product doesn’t have a
chance to warm up," adds Trostle. |
"We were concerned about any new
design and did every thing we could to make it fail. But it passed every test with no
problems. We’re ordering these on a regular basis from now on." Russell
computed some figures based on a 5-hp High Sierra system located in a cold climate, such
as Minnesota (45 degree average annual temperature) and power costs of $0.10/kWh. These
show an annual energy savings of $234 from the shorter defrost cycle, $140 from the larger
condenser-subcooler surface, and $280 from the floating-head technology, for annual
savings of $654.
There also would be $180 installation savings from the smaller refrigerant charge, and
$150 savings from the factory piped accessories and reduced electrical wiring. Over 10
years, this would add up to $6,540 (10x$654) plus $330 (installation savings of $180 and
$150), for total savings over a 10 year equipment life of $6,870.
That’s much more than the equipment cost to begin with.
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| Russell High Sierra refrigeration
systems are available with hermetic, semi-hermetic, or discus compressors in the
"Micon" design condensing units. The systems use AllTempB Series evaporators and
can be ordered compatible with R-404A or -22, in low-, medium-, or high-temp designs.
Contact the company at P.O. Box 1030, Brea, Calif. 92822-1030; 714-529-1935;714-529-7203
(fax). |
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|
221 S. Berry St.
Brea, CA 92821
(714) 529-1935
FAX (714) 529-7203 |
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