What is the required minimum flash point for the heat transfer fluid used in a solar system?

The required minimum flash point for heat transfer fluids used in a solar system is critical for safety and performance. Heat transfer fluids must have a sufficiently high flash point to prevent ignition during normal operating conditions, particularly given that these systems may be exposed to sunlight and varying temperatures.

A flash point of 50°F (28°C) ensures that the fluid remains safe under typical operating conditions and accidental exposure to heat sources. This temperature is chosen to minimize the risk of fire incidents and to meet safety regulations established in the mechanical code. Fluids with flash points below this threshold could pose a fire hazard, especially in systems that may experience fluctuations in temperature or pressure.

In contrast, lower flash points, such as 30°F (−1°C) or 40°F (4°C), do not provide the necessary safety margin to protect against the risk of ignition from potential heat sources in the solar system. Maintaining a flash point of at least 50°F helps to ensure that the system operates safely and effectively.