Which option lists the chiller coolant solution?

• A. Pure water
• B. A mixture of Ethaline glycol and water
• C. Ethylene glycol and water
• D. Propylene glycol and water

Answer: (B)

Chiller coolant needs to work across a wide temperature range, so the liquid must resist freezing while still transferring heat effectively. A glycol–water mixture does exactly that: glycol lowers the freezing point, preventing the coolant from solidifying in cold environments, and with proper additives it protects against corrosion and maintains good heat transfer. Pure water would freeze and cause flow problems, especially in cooling conditions below freezing, while pure glycol can be unnecessarily viscous and costly and may not optimize heat transfer. So a glycol–water blend (often ethylene glycol–water) is the practical, effective choice for chillers.