A geothermal heat pump system is the heating and cooling center piece of a new Phillips 66 Gas Station and convenience store in Prairie Village, Kansas.
What really sets the station apart is its novel and highly efficient integration of convenience store coolers and freezers into the system. The success of this system and two others in Oklahoma City and Dallas prompted Phillips 66 to adopt geothermal heat pumps as the standard for new station construction.
The system uses a closed-loop heat exchanger installed in ten 325-foot deep wells located around the perimeter of the station. A five-ton geothermal heat pump connected to this loop provides cooling in the summer and heating in the winter.
In addition, the station's four-ton walk-in cooler, freezer, and ice maker (all of which reject a substantial amount of heat that would ordinarily be wasted) have been tied into the system and contribute to a very high overall efficiency. Future stations will also include or incorporate geothermal heat pump water heating for the car wash and its floor ice melting system.
At a conventional station, there are several pieces of heating, cooling and refrigeration equipment installed on the roof. Quite often, the hot air exhaust from one unit is pulled into the cold air intake of another, greatly reducing the efficiency of the equipment.
The design of this station puts all the equipment inside the store, which eliminates this short circuiting and allows us to reduce cooler and freezer compressor sizes.
The Prairie Village station's heat pump has done an excellent job of keeping the store warm and comfortable. By connecting the water-cooled ice makers to the system, the station saves approximately 1,500 gallons of water per day at an average cost of more than $4 per 1,000 gallons of city water, while at the same time using 40 percent less electricity than comparable air-cooled models.
Because all of the equipment is located inside the store, there are fewer dirt, debris, and weather-related maintenance problems. It's easier to get at the equipment for regular maintenance, plus the store has a cleaner more appealing look with less potential for vandalism.
The decision by Phillips Petroleum can be traced in large part to the persistence of Joe Brown, (who designed service stations for the company) who has a geothermal heat pump in his home. Brown worked with Phil Shane and Florida Heat Pump to develop a design for applying the same technology to a service station.
The Prairie Village station saves about $800 a month on its electricity and water bills compared to a similarly sized Phillips 66 Store across town that uses conventional systems.