Hot-Holding Load, Demand, and Kitchen Heat Gain

Connected load, diversified demand, feeder amps, and kitchen heat gain from a line of hot-holding equipment, printed from one input list. Steam tables, holding cabinets, heat lamps, and soup wells are thermostatically cycling resistance heat. Connected load is the sum of the nameplates and is the wrong number to size anything by, because the units are never all in their on-cycle at the same moment; diversified demand, typically 0.6 to 0.75 for a mixed holding line, is what the feeder actually sees. The same demand number then does double duty, and that is the whole point: every watt a holding cabinet draws comes back out as sensible heat into the kitchen, so demand kilowatts convert directly to cooling load at 3412 BTU/hr per kilowatt with no efficiency to discount. Kitchens are routinely designed with the electrical load counted and the same load forgotten on the cooling side. Three 1.5 kW steam tables, two 0.5 kW heat lamps, and one 2.0 kW holding cabinet total 7.5 kW connected; at a 0.65 diversity that is 4.875 kW of demand, which on a 208 V three-phase service is 13.5 A and 16,634 BTU/hr, or 1.39 tons. Thirteen and a half amps is a modest feeder; nearly a ton and a half of cooling from six pieces nobody thinks of as heat sources is not, and that is before the fryers, the range, and the dish machine. Note that the exhaust hood captures only the fraction that rises into it, and the holding cabinet's share stays in the room. A load estimate; NEC Article 220 kitchen-equipment demand factors and the equipment nameplates govern the feeder, and the mechanical engineer's load calculation governs the cooling.

connected_kw = sum of (unit kW x quantity); demand_kw = connected_kw x diversity_factor; demand_amps = demand_kw x 1000 / (voltage x sqrt(3)) three-phase or / voltage single-phase; sensible_btuh = demand_kw x 3412; tons = sensible_btuh / 12000.

Diversified demand on a hot-holding line and its sensible heat gain, with the exact electrical-to-thermal conversion of 3,412 BTU/hr per kilowatt; NEC Article 220 kitchen-equipment demand factors and the equipment nameplates govern the feeder, and the mechanical engineer's load calculation governs the cooling.

The load arithmetic is public and the NEC demand factors are cited by article rather than reproduced. The equipment list, diversity factor, voltage, and phase are the designer's own values.

Estimate. AHJ and licensed professional govern.

Field names used by the API: equipment, diversity_factor, voltage, phase, connected_kw, demand_kw, demand_amps, sensible_btuh, tons

• Diversity factor typically 0.6 to 0.75 for a mixed holding line; connected load is not what the feeder seesfood-service electrical design practice
• Electrical to thermal 3,412 BTU/hr per kilowatt, exact for resistance heat with no efficiency to discountunit conversion
• Governing authority NEC Article 220 kitchen-equipment demand factors and the nameplates govern the feeder; the mechanical load calculation governs the coolingNFPA 70 (NEC) Article 220