Dowtherm A

Physical properties of Dowtherm A heat transfer fluid. DOWTHERM™ A is a eutectic mixture of biphenyl and diphenyl oxide, suitable for non-pressurized liquid phase systems with a maximum temperature of 550 °F (288 °C).

Dowtherm A Properties

DOWTHERM™ A is a eutectic mixture of:

  • Biphenyl (C₁₂H₁₀)
  • Diphenyl oxide (C₁₂H₁₀O)

Operating Range

  • Liquid phase: 15 °C to 400 °C (60 °F to 750 °F)
  • Vapor phase: 257 °C to 400 °C (495 °F to 750 °F)

Key Physical Properties

  • Freeze point: 12 °C (56.6 °F)
  • Boiling point (atmospheric): 257 °C (494.8 °F)
  • Flash point (SETA): 113 °C (236 °F)
  • Fire point (C.O.C): 118 °C (245 °F)
  • Autoignition temperature: 599 °C (1110 °F)
  • Density (at 25 °C/75 °F): 1056 kg/m³ (66 lb/ft³)
Calculator

Inputs

Results

Temperature-- °F
Estimated Density-- kg/m³
Estimated Density-- lb/ft³
Temperature (°C)Temperature (°F)Typical Density (kg/m³)Typical Density (lb/ft³)Application
1559107066.8Minimum liquid phase
2577105666Reference temperature
100212101063.1Moderate temperature
20039294559.1Higher temperature
25749590056.3Boiling point
40075280050.1Maximum operating
Dowtherm A | MEPKit Engineering Tools | MEPKit