Glycol & Heat Transfer Fluid Calculators
Four quick engineering tools for glycol coolants and thermal oils: freeze and burst protection, how much concentrate to buy or add, which ESSELTHERM fluid fits your temperature range, and how much your fluid expands when hot. Results are typical values for inhibited glycol-water solutions and the published ESSELTHERM data; always confirm with the TDS and, for glycol, a refractometer reading.
Glycol freeze point & burst protection
Enter a concentration to see the freeze point and burst point, or enter the lowest temperature you must protect against to get the concentration you need.
Freeze protection = no ice crystals form. Burst protection = ice slush forms but the fluid stays flowable and pipes do not burst, provided expansion volume is available. Industry practice: size for at least 5°F below the lowest expected ambient. Do not exceed 60% by volume — above that, freeze protection stops improving and heat transfer drops.
Glycol fill & top-up calculator
How much 100% concentrate to add to a new system, or how much to drain and replace in a system that is already running at a lower concentration.
Heat transfer fluid selector
Enter your operating envelope and we will list the ESSELTHERM grades that cover it. Minimum temperatures for thermal oils are the published pour points; keep a margin for pumpability.
Thermal expansion & expansion tank sizing
Thermal oils expand roughly 5–6% per 100°F. Use this to size the expansion tank and avoid overflow on start-up.
Expansion tank guidance: the tank should hold the full expansion volume with a 25–50% margin, be ¼ full cold and no more than ¾ full at operating temperature. Check the TDS and your system designer's requirements.
Freeze and burst data are typical published values for inhibited propylene and ethylene glycol solutions (Dow DOWFROST™ and DOWTHERM™ SR-1 engineering data; trademarks of their owners, used for reference only). Thermal oil data are from ESSELTHERM technical data sheets. SDI Chemicals provides these tools for guidance; final selection and concentration are the responsibility of the system owner.