Fluid properties
15 fluids, 12 of them as functions of temperature rather than a single pinned value.
A constant is one number that does not move. A fluid is not that: water at 5 °C and water at 80 °C differ in viscosity by a factor of four, and since Reynolds number scales as 1/µ, the same pipe at the same velocity can be in a different flow regime at the two ends of a building’s temperature range. These pages give every property at whatever temperature you actually have, and hand the whole state to a solver in one click so a density and a viscosity in the same calculation always describe the same fluid.
Treatment chemicals by strength
Specific gravity, density and pounds per gallon of sulfuric acid, caustic, hypochlorite, ferric chloride, alum and more, at the strength on the label.
Water, air & steam 3
Water
ρ = 998.2 kg/m³ at 20 °Cµ = 1.002 mPa·sLiquid water from 0 to 100 °C at 1 atm — density, viscosity, specific heat, thermal conductivity and vapour pressure, all at the same state.
density · dynamic viscosity · specific heat · thermal conductivity · vapour pressure · latent heat of vaporisation
Dry air
ρ = 1.2041 kg/m³ at 20 °Cµ = 0.01813 mPa·sDry air at 1 atm from −50 to 300 °C — the ideal-gas density and Sutherland viscosity behind every duct, fan and drag calculation.
density · dynamic viscosity · specific heat · thermal conductivity
Saturated steam saturated
ρ = 2.5481 kg/m³ at 150 °Cµ = 0.01396 mPa·sDry saturated steam from 100 to 200 °C — saturation pressure, vapour density and latent heat along the boiling line that low and medium pressure steam heating runs on.
density · dynamic viscosity · specific heat · thermal conductivity · vapour pressure · latent heat of vaporisation
Glycol heat transfer fluids 7
Freeze points by concentration
Both chemistries, 0 to 60 % by volume, °C and °F: the classic curve, and a solver that answers “the design day is −25 °C, how much glycol does the loop need?”
Propylene glycol, 20 % by volume
ρ = 1,015.3 kg/m³ at 20 °Cµ = 2.08 mPa·sA 20 % by volume propylene glycol solution, freeze protection to about −7 °C — the corrosion floor: any leaner and the inhibitors are too dilute to trust.
density · dynamic viscosity · specific heat · thermal conductivity
Propylene glycol, 30 % by volume
ρ = 1,024.5 kg/m³ at 20 °Cµ = 3.06 mPa·sA 30 % by volume propylene glycol solution, freeze protection to about −13 °C — the usual charge for a snowmelt or make-up air loop that only has to survive a Canadian shoulder season.
density · dynamic viscosity · specific heat · thermal conductivity
Propylene glycol, 40 % by volume
ρ = 1,033 kg/m³ at 20 °Cµ = 4.54 mPa·sA 40 % by volume propylene glycol solution, freeze protection to about −21 °C — the middle charge — full winter protection at a manageable pumping penalty.
density · dynamic viscosity · specific heat · thermal conductivity
Propylene glycol, 50 % by volume
ρ = 1,039.6 kg/m³ at 20 °Cµ = 6.62 mPa·sA 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.
density · dynamic viscosity · specific heat · thermal conductivity
Propylene glycol, 59 % by volume
ρ = 1,043 kg/m³ at 20 °Cµ = 9.24 mPa·sA 59 % by volume propylene glycol solution, freeze protection to about −50 °C: the deepest charge the open data reach, and viscosity is now the design constraint.
density · dynamic viscosity · specific heat · thermal conductivity
Reference liquids 3
Seawater single state
ρ = 1,025 kg/m³ at 15 °Cµ = 1.19 mPa·sOpen-ocean seawater at 35 g/kg salinity and 15 °C — 1025 kg/m³, the 64 lb/ft³ that separates salt-water from fresh-water load lines.
density · dynamic viscosity · specific heat · thermal conductivity
Refrigerants 2
R-134a (saturated liquid) saturated
ρ = 1,225.3 kg/m³ at 20 °Cµ = 0.2074 mPa·sR-134a saturated liquid from −40 to 60 °C — the single-component HFC whose saturation table underpins most automotive and medium-temperature commercial refrigeration.
density · dynamic viscosity · specific heat · thermal conductivity · vapour pressure · latent heat of vaporisation
R-410A (saturated liquid) saturated
ρ = 1,083.3 kg/m³ at 20 °Cµ = 0.1273 mPa·sR-410A saturated liquid from −40 to 60 °C — the high-pressure blend in most modern split systems and heat pumps, running roughly 60 % above R-134a pressures.
density · dynamic viscosity · specific heat · thermal conductivity · vapour pressure · latent heat of vaporisation