HARRIS TEETER TO TEST NATURAL GAS POWERED AIR CONDITIONING

LINDA PURPURA

CHARLOTTE, N.C. -- Harris Teeter here is investigating new ways to save on electricity, including a test this summer of a natural gas-driven air conditioning system in one of its stores here.

This relatively new type of technology can run on either electricity or natural gas, to take advantage of electric rate variations at different times of day.

The retailer is also using antisweat controls on reach-in frozen food cases in 15 of its stores. One store's return on investment for the technology, which saves energy and prevents condensation on the units' glass doors, took less than a year, according to Howard Price, manager of mechanical systems at Harris Teeter.

The new air conditioning system was installed late last summer, so it was not tested for any significant length of time before cooler weather set in.

This summer, Harris Teeter will be able to fully test the system to determine if it provides energy savings and is a viable alternative to electric power during peak times, said Price.

"We hope to see some savings over straight electricity, and that the unit will pay for itself out of energy savings in two to three years," he said.

The savings would be derived from running the system on natural gas when that form of energy is most economical, during the day when electric power is at peak rates. The system would be powered by electricity when that form of energy is cheapest, at night during off-peak rates.

Price said natural gas-driven air conditioning systems are very new technology and are not widely used in the supermarket industry. The test results will help determine whether Harris Teeter will use the technology in new stores or major remodelings of existing stores, he added.

The retailer has also installed antisweat controls on reach-in frozen-food cases in about 15 of its stores as they have been remodeled, according to Price.

"We saw about a nine-month payback in one store in Charlotte, N.C.," Price said. While the antisweat technology itself is not new, it has recently improved in reliability, he noted.

An antisweat control on reach-in frozen food cases senses the humidity in the building. To prevent excess use of energy, the control turns heaters located around the door frames and on the glass on and off as needed.

These heaters are designed to raise the dew point temperature in the case to prevent condensation. Without the heaters, the door frames and glass get very cold and condensation forms on them.