The estimated annual drying capacity is based on 40 days' use per year. If the dryers can be used more than 40 days a year, the drying cost per ton decreases. Figure 2.1 shows alternative drying methods for annual drying requirements, based primarily on drying capacity. Any final decision must also consider labor, management, and technical requirements; relation of drying to other factors, such as receiving, conveying, and storage facilities; and investment and operating costs.