xdxadmin
08-31-2004, 11:20 AM
Field Test and Verification of a Complete Supermarket – XDX® Analysis - Fourth Quarter 2001 through second Quarter 2002 – Independent Verification of Data By Customer, K-Mart Corporation
A chain supermarket has an installed compressor capacity of 257 kW (344.5 HP) distributed unevenly across five parallel compressor systems. This test program consisted of monitoring 134 DX evaporators for performance and 32 of the display cases and unit coolers were fitted auxiliary National Institute of Standards and Technology (NIST) rated temperature sensors in product area locations for control and verification purposes. The store was monitored for case temperature, kW and kWh for a period of four weeks prior to any retrofit of evaporative coils to establish a baseline. The largest three compressor rack systems were independently monitored for power. The supermarket compared its in-house data for the previous eighteen months and verified the baseline data. All refrigeration system work was conducted by the local refrigeration contractor that was most familiar with the facility.
• Rather dramatic results were observed:
o Temperatures were significantly reduce
o Product quality with related quantified savings in soft costs
o Power (kW) and energy usage (kWh) was dramatically reduced.
o Mechanical improvements were experienced
o Defrost frequency was reduced by at least fifty percent (50%) in frequency, while defrost duration was often reduced.
o Oil return from the low temperature systems was reported as significant enough to cause blockage of all of the suction line filter driers on more than one occasion with the debris and residue that had been logging in the evaporators.
o Superheat was reduced
o Supply air temperatures were reported reduced
Key: Supermarkets, Refrigerated Display Cases, Freezer Display Cases, Reach-in Coolers, Deli Counters, Door Freezers, Rack Systems
A chain supermarket has an installed compressor capacity of 257 kW (344.5 HP) distributed unevenly across five parallel compressor systems. This test program consisted of monitoring 134 DX evaporators for performance and 32 of the display cases and unit coolers were fitted auxiliary National Institute of Standards and Technology (NIST) rated temperature sensors in product area locations for control and verification purposes. The store was monitored for case temperature, kW and kWh for a period of four weeks prior to any retrofit of evaporative coils to establish a baseline. The largest three compressor rack systems were independently monitored for power. The supermarket compared its in-house data for the previous eighteen months and verified the baseline data. All refrigeration system work was conducted by the local refrigeration contractor that was most familiar with the facility.
• Rather dramatic results were observed:
o Temperatures were significantly reduce
o Product quality with related quantified savings in soft costs
o Power (kW) and energy usage (kWh) was dramatically reduced.
o Mechanical improvements were experienced
o Defrost frequency was reduced by at least fifty percent (50%) in frequency, while defrost duration was often reduced.
o Oil return from the low temperature systems was reported as significant enough to cause blockage of all of the suction line filter driers on more than one occasion with the debris and residue that had been logging in the evaporators.
o Superheat was reduced
o Supply air temperatures were reported reduced
Key: Supermarkets, Refrigerated Display Cases, Freezer Display Cases, Reach-in Coolers, Deli Counters, Door Freezers, Rack Systems