What type of water is commonly used to cool a coil that is part of an HVAC system?

The type of water commonly used to cool a coil in an HVAC system is often treated water, not typically the options provided. However, misunderstanding can arise from other contexts where water sources are substituted in various applications. Pool water may be used in some specific cooling applications due to its availability and temperature control features, especially in systems designed to utilize thermal mass.

In HVAC systems, cooling coils primarily rely on chilled water, which is specifically cooled by a chiller and recirculated through the system. The most common type of water used for cooling in building HVAC systems is usually treated municipal water or chilled water from a dedicated cooling system.

While tap water is also a form of municipal water, it usually becomes part of the overall system strategy, incorporating temperature control, filtration, and chemical treatment, making it more applicable than simply using regular pool, rain, or seawater. Rainwater can also be used in some installations but typically requires more treatment processes to ensure water quality and system efficiency. Seawater is generally unsuitable for typical HVAC cooling due to its salinity, which can cause corrosion and scale buildup in cooling systems.

Using pool water in this context suggests a method of exploring alternative cooling solutions, although for conventional HVAC applications, treated chilled water remains standard. Therefore