Life-cycle cost and benefit analysis of utilizing hoods for light-duty cooking appliances in commercial kitchens (RP-1631, part 2)

The objective of this study was to compare the life-cycle cost of using a dedicated hood exhaust and replacement air system versus the cost of removing heat and moisture by the kitchen's general HVAC system. With measured sensible and latent heat generation data from Part I of the RP-1631, whole-building energy performance simulations and cost–benefit analysis were conducted for a generic prototype model of restaurants/cafeteria that included a dining and kitchen zone. Simulations were performed for 12 climate zones in the United States and different amounts of transfer air from the dining to the cooking zone. For most of the climates simulated, the hooded cases resulted in an increase in energy consumption, particularly for the heating-dominated regions, since the heat from the appliance was not used for space heating. In the cooling dominated regions, the hooded cases had about the same or less energy consumption due to reduced cooling loads. However, after integrating the initial cost, maintenance cost, and operating cost in a 10-year lifespan, utilizing a hood with 100% TR always gave the lowest life-cycle cost. This is a result of the lower operating cost compared to the unhooded case and no need for a makeup air system, saving in both equipment and operating cost, compared to the other hooded cases. The study fills a knowledge gap on the impact of commercial kitchen HVAC system design on the energy consumption and life-cycle-cost with realistically measured data of heat and moisture generation from electric counter-top cooking appliances. Also, the potential impact of the hood's capture efficiency on the thermal comfort and indoor air quality was analyzed.