What are some common mistakes to avoid when designing HVAC piping systems?

Some common mistakes to avoid when designing HVAC piping systems include undersizing pipes, ignoring friction loss, and neglecting to consider pipe material and roughness. Other mistakes include failing to account for changes in pipe diameter, not providing adequate pipe support, and neglecting to consider the impact of valves and fittings on friction loss. By avoiding these common mistakes, designers can create efficient and effective HVAC piping systems that minimize friction loss and optimize system performance.