Laser Winter Protection Guide: Tips for Protecting Lasers

Introduction

As temperatures gradually drop, winter anti-freeze measures become a most easily overlooked, yet extremely critical, aspect of safe laser equipment operation. Especially for equipment like fiber laser cutting machines, welding machines, and marking machines, the laser internally uses a precision water-cooling system. Once the coolant freezes, it can directly cause serious damage to fiber interfaces, piping, and even laser modules. To ensure stable equipment operation and avoid high repair costs, this article details the anti-freeze principles, temperature requirements, specific measures, and coolant selection methods for lasers in winter, helping you easily cope with cold, low-temperature environments.

Basic Principles of Anti-Freeze

Lasers typically rely on a chiller circulating coolant to remove operational heat and maintain stable optical output. In winter, when the ambient temperature drops below 0°C, the coolant may freeze and expand, leading to the following issues:

• Water pipes or connectors cracking;

• Laser module cooling cavity damage;

• Fiber connection ends being damaged by freeze expansion;

• Chiller pump body or heat exchanger freezing and cracking.

Therefore, the fundamental goal of anti-freeze is to prevent the coolant from freezing within the system. This can be achieved by maintaining the ambient temperature, draining the coolant, or using anti-freeze fluid.

Laser Operating Temperature Requirements

Lasers are precision equipment extremely sensitive to temperature. The recommended operating environment temperature for lasers is between 10°C and 40°C. In winter, the chiller's low-temperature water setting should be 20°C, and the high-temperature water setting should be between 28°C and 30°C.

When the temperature is too low, the internal temperature control of the chiller cannot heat up promptly. After the laser starts, it is prone to alarms and unstable output due to condensation or freezing. Therefore, before operating the laser in winter, the chiller must run for more than 20 minutes to ensure the coolant actually reaches the set temperature and avoid low-temperature shock.

Winter Anti-Freeze Solutions

1. Maintain a Constant Ambient Temperature
Where conditions permit, place the laser and chiller in an enclosed room or install heating facilities to keep the working environment temperature stable within 10–40°C.

2. Keep the Chiller Running
In cases where local power outages are unlikely, if the equipment will be idle for extended periods, keep the chiller running, setting both the low-temperature and normal-temperature water to around 5°C (ensuring the coolant remains above freezing while saving energy).

3. Drain the Coolant from the Machine

After each use, drain the coolant from the laser.

Disconnect the water inlet pipe from the laser, then use compressed gas to blow through the inlet (WATER IN) until the residual water in the laser's water cooling channels is expelled from the outlet. Then close the valves and plug the inlet and outlet ports with rubber stoppers to prevent foreign objects from entering the water lines.

Disconnect the water inlet pipe from the laser, then use compressed gas to ventilate through the inlet (WATER IN) until the residual water in the laser's water cooling channels is expelled from the outlet. Then plug the inlet and outlet ports with rubber stoppers to prevent foreign objects from entering the water lines.

4. Use Anti-Freeze Fluid Mixed with Coolant
When the usage environment experiences temperatures below 0°C, frequent power outages, or if draining the coolant daily is not feasible, adding anti-freeze fluid is essential.

Selection of Anti-Freeze Fluid

1. Choose an anti-freeze fluid with a suitable freezing point based on the local temperature. The selection is not about the lower the freezing point the better; simply choose one with a freezing point slightly below the local minimum temperature.
2. The recommended brand for chiller anti-freeze fluid is Clarinet. 

Special Notes:

(1) After adding anti-freeze fluid, the heat transfer capacity and flow rate of the coolant will decrease, and the overall heat dissipation of the laser will worsen. If your laser displays any temperature alarm, do not frequently restart and use it.

(2) No anti-freeze fluid can completely replace deionized water or distilled water. It is not recommended for prolonged use year-round. When temperatures rise, be sure to flush the system and resume using deionized water or distilled water as the coolant.

(3) For long-term shutdowns (e.g., during work stoppages, before laser transport), the coolant inside the equipment must be drained, and compressed air should be used to blow out residual water from inside the equipment (including the laser and chiller) to prevent internal freezing and component damage.