Taco Tower for Food Service Applications

It is common for major players in the food service industry to use custom-designed cooking and refrigeration equipment. Often times, the absence of baseline performance data or test standards does not allow food service operators to have access to their equipment’s performance data under realistic operating conditions. One of Southern California Edison’s (SCE’s) major fast food customers was interested in understanding the energy impacts of a potential retrofit of a piece of existing kitchen equipment called the “Taco Tower”. Concurrently, Customer was experiencing Heating, Ventilating, and Air Conditioning (HVAC) sizing issues resulting in uncomfortable work environments in the kitchen space. Testing of this equipment was conducted in TTC’s new Calorimeter Controlled Environment Laboratory (CCEL). The CCEL is a walk-in cooler with a sophisticated climate control system and the ability to measure the amount of cooling, heating, or humidity provided to maintain conditions. From these measurements, it is possible to determine the amount of energy directly consumed by a piece of equipment as well as its impact on surrounding space conditioning systems. Each piece of equipment was operated inside the CCEL for a two-hour test period with temperature maintained at 75°F. Testing replicated realistic operating patterns found in the field for each piece of equipment. Food product was only introduced for three pieces of equipment. Readings from 142 channels of data were collected every 20 seconds and analyzed to determine energy consumption and cooling load impacts. Twenty-six test scenarios were conducted. Heated air curtain Taco Towers from two different manufacturers were compared to the existing Taco Towers used in two different kitchen configurations (I Line / Dual Line). The new Taco Tower is envisioned to replace multiple pieces of existing equipment, not just the existing Taco Tower. On a strictly energy basis, only one of the new Taco Towers provided benefit over the existing equipment, and only in one kitchen configuration (I Line). In other cases, the energy consumption nearly doubled. However, there may be non-energy benefits to Customer from implementing the new technology. A study of the HVAC cooling loads imposed by each piece of equipment revealed that the major load contributors are the Line components, including the Taco Towers (Figure 1). Latent loads were dominated by the Power Soak sink, though additional load may be attributed to other sources, including food products that were not present for this testing.