The advantages of this system are that air does not need to be protected from
freezing or boiling, is non-corrosive, does not suffer from heat transfer fluid degradation, and is free. Additionally, the system is more cost effective because no
safety values or expansion vessels are required. The disadvantages are that airhandling equipment (ducts and fans) needs more space than piping and pumps,
air leaks are difficult to detect, and parasitic power consumption (electricity used
to drive the fans) is generally higher than that of liquid systems.