What is the most common unit for measuring pressure in HVAC systems?

The most common unit for measuring pressure in HVAC systems is pounds per square inch. This measurement is widely used in the industry due to its practicality and historical usage in the United States. PSI provides a clear and intuitive way to express pressure levels in refrigerant systems and air handling processes, making it easier for technicians and engineers to communicate system performance and requirements.

While other units like Pascals or feet of water can be used in specific applications or regions, PSI remains the standard in many HVAC contexts, particularly in North America. Degrees Fahrenheit, on the other hand, measures temperature rather than pressure, making it irrelevant in this context.