The HC2400 cools or warms incoming air from compressed breathing air sources. It is ideally suited for early spring or late fall when the air needs warming in the morning and cooling in the afternoon. When used in the cool mode, the Hot/Cold Tube decreases the incoming air temperature by as much as 17°C (30°F). When warm air is desired, the incoming air temperature may be increased by up to 17°C (30°F). The HC2400 features an adjustable airflow control valve that allows users to regulate the temperature of inco- ming air to a comfortable level. It is simple to convert the HC2400 from cool air to warm air or warm to cool. It takes the worker just seconds to convert from one mode to the other and then resume work activity.