Fluids / Propylene glycol, 50 % by volume
Dynamic viscosity of propylene glycol, 50 % by volume vs temperature
A 50 % by volume propylene glycol solution, freeze protection to about −33 °C — full winter protection, and the concentration where the pumping penalty stops being ignorable.
Dynamic viscosity in mPa·s, from -30 to 100 °C. The chart and the table below are the same numbers; the table is the one you can copy.
| Density | 1,041 kg/m³ |
| Specific heat | 3.54 kJ/(kg·K) |
| Thermal conductivity | 0.388 W/(m·K) |
| Temperature (°C) | Dynamic viscosity (mPa·s) | Row |
|---|---|---|
| -30 | 130 | published |
| -20 | 62 | published |
| -10 | 33 | published |
| 0 | 19.5 | published |
| 10 | 11.904 | interpolated |
| 20 | 7.6 | published |
| 30 | 5.2427 | interpolated |
| 40 | 3.8 | published |
| 50 | 2.8359 | interpolated |
| 60 | 2.2 | published |
| 70 | 1.7952 | interpolated |
| 80 | 1.5 | published |
| 90 | 1.2529 | interpolated |
| 100 | 1.05 | published |
Rows marked published land exactly on a source anchor and are the tabulated figure. The rest are this library’s interpolation between the two anchors either side — good enough to design with, and said out loud so you can decide that for yourself.
ASHRAE Handbook—Fundamentals, Ch. 31 (Secondary Coolants), interpolated from published tables · validated -30 to 100 °C · interpolated between 9 published anchors (values held, not extrapolated, past the ends)