Freeze protection for dry coolers at -20°C?

Freeze protection for dry coolers at -20°C?

Short answer

At -20°C, freeze protection comes from ethylene glycol-based antifreeze plus VFD fan control. Electric or electromagnetic heating modules are not mandatory — they serve only as auxiliary de-icing tools. A closed-loop system with properly concentrated glycol provides full protection.

  • Ethylene glycol is the primary defense
  • VFD fan control manages cold operation
  • Heating modules are auxiliary only
  • Closed loop keeps protection complete

How the three layers work together

Containers with dry coolers operating outdoors in cold conditions
Outdoor dry cooler loop — the part that needs antifreeze protection.
  • Glycol concentration does the real work. A properly concentrated ethylene glycol mixture keeps the loop liquid at -20°C.
  • VFD fan control adapts the reject rate. Fans slow or stop as conditions allow, protecting the loop and recovering energy.
  • Heating modules are optional. They de-ice as an auxiliary measure — the design does not depend on them.
  • Closed-loop design closes the gap. With the right concentration, the system is protected without auxiliary heat.
Coolant loop hoses and manifold inside a container
The loop that carries the glycol mixture.
Container paired with a dry cooling tower
The outdoor coil circuit protected against freezing.

Related questions

What type of coolant is required for the SR40 V3 system? Purified water vs. glycol: How do ratios affect cooling? How does the SR40 V3 perform in extreme ambient temperatures?

Engineering coolant concentration for a cold site? Talk to a CoolSpace engineer