What is the range of the difference of air temperature at inlet and outlet?

In the context of HVAC (Heating, Ventilation, and Air Conditioning) systems or various industrial processes, the difference in air temperature between the inlet and outlet, often referred to as the temperature rise or delta T (ΔT), varies widely depending on the application, system design, and operating conditions.

1. For HVAC Systems: The typical range of temperature difference for heating might be between 20°F to 50°F (-6.67°C to 10°C). For cooling applications, the desired outlet temperature is often closer to indoor comfort levels, with systems designed to achieve a temperature drop that maintains indoor conditions within a desirable range, typically aiming for a ΔT of 15°F to 20°F (-9.44°C to -6.67°C).

2. For Industrial Processes: The range can be significantly broader. Industrial heat exchangers, coolers, or heaters might have a ΔT from a few degrees to over 100°F (37.78°C), depending on the process requirements, the medium being cooled or heated, and the efficiency of the system.

The specific range for any given application depends on the goals of the system (e.g., achieving a particular temperature, maximizing energy efficiency), the properties of the fluids or gases being heated or cooled, and the capacity of the equipment used.