Ethylene Glycol / Water Mixture Properties

Ethylene Glycol / Water Mixture Properties

Mixtures of Ethylene Glycol and water are commonly used as an antifreeze or heat transfer fluid, such as in our GlycoChill+ E-series Heat Transfer Fluids. Here are the chemical and physical properties of Ethylene Glycol/water mixtures.

 

Appearance / Odor

Ethylene Glycol and water are both naturally clear and liquid in appearance. However, if the mixture is a heat transfer fluid dyed to industry standards, such as GlycoChill+ ‘E’ Series, it will be pink. A slight, sweet odor may be present.

 

Ethylene Glycol/Water Mixture Properties

Chemical Properties

Ethylene Glycol is completely miscible in water at all concentrations. An Ethylene Glycol / Water mixture will never separate, unless it is freezing, at which point ice crystals will form into a “slushy-like” solution before freezing solid which is known as burst point. This is the reason that the burst point is always lower than the freeze point in a glycol/water solution. Ethylene is a marine pollutant and has a high toxicity if ingested; otherwise, it outperforms its cousin, propylene glycol, on viscosity, specific heat, freeze point & thermal conductivity.

 

Density

The density (ρ) values of an ethylene glycol/water mixture are shown in the table below. This is displayed in kilograms per cubic meter (kg/m3) .

Mass Fraction of E.G. in Solution -48°C (-54.4°F) -35°C (-31°F) -25°C (-13°F) -14°C (6.8°F) -8°C (17.6°F) -4°C (24.8°F) 0°C (32°F) 20°C (68°F) 40°C (104°F) 60°C (140°F) 80°C (176°F) 100°C (212°F)
0 1000 998 992 983 972 958
0.1 1019 1018 1014 1008 1000 992 984
0.2 1038 1037 1036 1030 1022 1014 1005 995
0.3 1058 1056 1055 1054 1046 1037 1027 1017 1007
0.4 1080 1077 1075 1073 1072 1063 1052 1041 1030 1018
0.5 1103 1100 1096 1093 1092 1090 1079 1067 1055 1042 1030
0.6 1127 1124 1120 1115 1112 1110 1107 1095 1082 1068 1055 1042

 

Freezing Point / Boiling Point

Freeze points and boiling points may be found on the freeze point charts for our GlycoChill+ ‘E’ Series product line: Freeze Point Chart – GlycoChill+ Ethylene Glycol Heat Transfer Fluid. As a mixture gets close to the freezing point, slush may begin to form and the mixture should not be used.

 

pH 

pH is the measure of how acid or alkaline (basic) a substance is. For more information on pH, see What is pH? Acids & Bases Explained. The typical pH values of our GlycoChill+ ‘E’ Series Heat Transfer Fluids vary between 9.25 – 10.75, meaning that the solution is basic in nature. View the product data sheet for the specified range for a particular product.

 

Reserve Alkalinity 

Reserve Alkalinity (RA) is measured in millilitres (ml). The values indicate the amount of alkaline components present in the product, or how resistant a fluid is to becoming acidic. Generally, the more Ethylene Glycol in a solution, the higher the Reserve Alkalinity is. Over time, as the useful lifespan of the product is used up, and the product becomes ‘spent’, the Reserve Alkalinity is diminished. A 30 – 40% solution may have an RA in the 4.5 – 6.0 ml range, while an 80% solution may have an RA in the 15 – 20 ml range. Reserve Alkalinity specifications for our GlycoChill+ products may be found on the product data sheet.

 

Specific Gravity 

The Specific Gravity of a solution is the ratio of its density compared to the density of water. Refer to the product data sheet of our heat transfer fluid products for a specified range for a particular product at 20°C.

E.G. Solution, Vol.% -40°C (-40°F) -17.8°C (0°F) 4.4°C (40°F) 26.7°C (80°F) 48.9°C (120°F) 71.1°C (160°F) 93.3°C (200°F)
25 1.048 1.04 1.03 1.018 1.005
30 1.057 1.048 1.038 1.025 1.013
40 1.08 1.07 1.06 1.05 1.038 1.026
50 1.10 1.088 1.077 1.064 1.05 1.038
60 1.12 1.11 1.1 1.09 1.077 1.062 1.049
100 1.16 1.145 1.13 1.115 1.1 1.084

 

Specific Heat 

Specific Heat, or Specific Heat Capacity (cp), is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. The amount of heat required is expressed as BTU’s; the chart below shows the Specific Heat values of an ethylene glycol/water mixture expressed as BTU’s per pound per degree Fahrenheit (Btu/lb oF).

E.G. Solution, wt.% -50°C (-58°F) -40°C (-40°F) -30°C (-22°F) -20°C (-4°F) -10°C (14°F) 0°C (32°F) 10°C (50°F) 20°C (68°F) 30°C (86°F) 40°C (104°F) 50°C (122°F) 60°C (140°F) 70°C (158°F) 80°C (176°F) 90°C (194°F) 100°C (212°F)
0 1.0038 1.0018 1.0004 0.99943 0.99902 0.99913 0.99978 1.0009 1.0026 1.0049 1.0076
10 0.97236 0.97422 0.97619 0.97827 0.98047 0.98279 0.98521 0.98776 0.99041 0.99318 0.99607
20 0.93576 0.93976 0.94375 0.94775 0.95175 0.95574 0.95974 0.96373 0.96773 0.97173 0.97572
30 0.89373 0.89889 0.90405 0.90920 0.91436 0.91951 0.92467 0.92982 0.93498 0.94013 0.94529 0.95044
40 0.84605 0.85232 0.85858 0.86484 0.87111 0.87737 0.88364 0.88990 0.89616 0.90243 0.90869 0.91496 0.92122
50 0.79288 0.80021 0.80753 0.81485 0.82217 0.82949 0.83682 0.84414 0.85146 0.85878 0.86610 0.87343 0.88075 0.88807
60 0.72603 0.73436 0.74269 0.75102 0.75935 0.76768 0.77601 0.78434 0.79267 0.80100 0.80933 0.81766 0.82599 0.83431 0.84264 0.85097
70 0.67064 0.67992 0.68921 0.69850 0.70778 0.71707 0.72636 0.73564 0.74493 0.75422 0.76350 0.77279 0.78207 0.79136 0.80065 0.80993
80 0.61208 0.62227 0.63246 0.64265 0.65285 0.66304 0.67323 0.68343 0.69362 0.70381 0.71401 0.72420 0.73439 0.74458 0.75478 0.76497
90 0.58347 0.59452 0.60557 0.61662 0.62767 0.63872 0.64977 0.66082 0.67186 0.68291 0.69396 0.70501 0.71606
100 0.53282 0.54467 0.55652 0.56838 0.58023 0.59209 0.60394 0.61579 0.62765 0.63950 0.65136 0.66321

 

Thermal Conductivity 

Thermal conductivity is the rate at which heat passes through a material i.e., ethylene glycol & water mixture. Since water is seen as the “golden standard” in thermal conductivity, higher concentrations of ethylene glycol in a water solution will cause heat to pass through it slower, therefore, the lower the amount of ethylene glycol in the mixture, the more efficient it is at conducting heat.

 

Viscosity, Dynamic

An ethylene glycol/water mixture will be slightly viscous, though viscosity will vary depending on temperature and volume. The lower the temperature, the thicker and more viscous the solution will become, meaning it will be harder to pump and handle and may require larger pumps. However, note that solutions of ethylene glycol are less viscous at lower temperatures than solutions containing propylene glycol. Dynamic viscosity is useful to know when designing pumping systems. Here are values of dynamic viscosity for ethylene glycol/water mixtures.

E.G. Solution, Vol.% -17.8°C (0°F) 4.4°C (40°F) 26.7°C (80°F) 48.9°C (120°F) 71.1°C (160°F) 93.3°C (200°F)
25 3 1.5 0.9 0.65 0.48
30 3.5 1.7 1 0.7 0.5
40 15 4.8 2.2 1.3 0.8 0.6
50 22 6.5 2.8 1.5 0.95 0.7
60 35 9 3.8 2 1.3 0.88
100 310 48 15.5 7 3.8 2.4