What is the primary purpose of a mixing box in an HVAC system?

The primary purpose of a mixing box in an HVAC system is to combine air streams and regulate temperature. Mixing boxes receive multiple sources of air, often including fresh air from outside and recirculated air from the building. By blending these air streams, the mixing box helps to achieve the desired temperature setpoint for the space being conditioned.

This integration of air is vital for maintaining comfortable indoor environmental conditions and optimizing energy efficiency. Properly regulated air temperatures can prevent overcooling or overheating, ensuring that the HVAC system operates effectively.

While filtering air contaminants is essential for air quality, this function typically falls under the responsibility of air filters rather than the mixing box itself. Similarly, ambient air circulation is achieved through other components of the HVAC system, and while maintaining system pressure is important, it relates more to the overall design and operation of the HVAC system rather than the specific function of the mixing box.