Two heating systems were investigated to evaluate the potential curing costs savings with the additional benefit of minimizing tobacco-specific nitrosamines (TSNA) levels in the cured leaf. One system utilized a woodchip fired hot water system to generate heat for the curing process. The boiler is centrally located and hot water was circulated to the curing barns. Utilization of a woodchip fired hot water system reduces curing cost by utilizing a lower cost fuel than LP gas and it removes all combustion products from the barn. Thermal energy cost for curing was approximately $0.02 to $0.04 per pound of cured leaf based on woodchip prices ranging $25 to $30 per ton. The high initial cost is prohibitive for some growers and the pay-back period can be reduced if the system is utilized for more applications throughout the year. The second system utilized a variable firing rate gas burner to reduce thermal cycling and potentially extend the life of the heat exchanger. Thermal cycling of the indirect-fired heat exchangers causes material fatigue which results in cracks allowing combustion gases to enter the curing environment. Typical burner duty cycles range approximately 4 minutes on and 1 1/2 minutes off during leaf drying, which is the point in the curing process that requires the most heat. The variable firing rate (VFR) burner can automatically adjust the heat output based on the barn thermal load. As a result, the burner operates continuously during parts of the curing process and minimizes thermal cycling. The number of cycles can be reduced from 7% to 72% with a VFR burner compared to a conventional burner. Fuel savings varied from location, but the thermal cycling was reduced at all locations. (Reprinted with permission)