What must solid fuel-burning appliances comply with for combustion air requirements?

Solid fuel-burning appliances must comply with the appliance manufacturer's installation instructions concerning combustion air requirements because these instructions are specifically designed to ensure safe and efficient operation of the appliance. The manufacturer has tested the unit under defined conditions and has provided guidelines that consider various factors such as the design, materials used, and intended application of the appliance. Following these instructions helps to ensure adequate combustion air supply, which is crucial for proper fuel burning, minimizing emissions, and preventing hazardous conditions like backdrafting or incomplete combustion.

While local building codes and general HVAC guidelines provide overarching regulations and best practices, they may not account for the specifics of individual appliances. International standards could offer broader context as well, but the direct compliance with manufacturer instructions takes precedence as they are tailored to the specific operational characteristics needed for safety and efficiency.