Winter is coming for my CO2 laser who is allergic to freezing temperatures

As winter is coming and CO2 laser engravers are allergic to freezing temperatures, I would like to have some help with a bit of a design. I have half a plan but that won’t be enough for a reliable setup with ESPhome. if anyone could push me in the right direction that would be great.

This is the situation: a CO2 laser has water cooling. The space where the laser is can freeze at night. In the laser there a few modules that work to keep the water cool when the laser is on and warm in winter.

  • water chiller to cool the water when the laser is in operation. This is a compressor with proper heat exchanger.
  • DC fish tank heaters to prevent the water from freezing connected with MOSFET on a 5V PSU
  • Heat exchanger with a fan (240V) to cool water when laser is in operation.
  • There will be 3 thermometers to keep track on the water, temp close to the tube and outside of the machine.
  • ESP32 devboard with 4 relays
  • Water pump (240V)
  • Tank with about 1-1,5 l of water

The perfect operation temperature for the laser is 20-25 degrees C.

The operations:

  • Machine off at night
    • When ambient temp is below 5 degrees the water temp set to 5 degrees, water pump is running . Fish tank heaters will keep the temp to 5 degrees.
    • When ambient temperature is above 5 everything is just off.
  • It’s cold and we want to start working with machine. Water temp set to 20 degrees, when temp is at 20 we can start firing up the laser
  • In operation, water pump will be running all the time.
    • if water comes above 21 degrees the heat exchange fan will turn on to keep the water as cool as possible within his range and ambient temp.
    • if water comes above 23 degrees the water chiller will turn on.
    • if ambient temp is above 24 degrees the heat exchange should NOT run as it will warm the water instead of cool.
  • Cool down period after laser work. The fan for the heat exchanger will stop at 20 degrees to prevent the water to cool too much. Depending on ambient temperatures the water will cool back to 5 and come back to first point.
  • if ambient temperature goes below 2 degrees a warning will go out.
  • If sensor close to the laser will go below 2 degrees the set temperature should go up to prevent condensation on the tube.

My thoughts ware to use the climate PID component. Together with the MOSFET it can keep the temperature relative stable. Manually setting it to 20 when we want to do the work. The Fan should be able to be controlled when above 21 and chiller on after 24 degrees. Only thing that bubbles my mind is that the fan should not run below 20 degrees water or above 24 degrees ambient. Also the emergency rise of temp if tube gets too cold. I prefer not to set different climate components, but I am not sure how to do that.

I know, lots of text but could not find another way to explain. If someone can reach out with idea’s that would be fabulous.

How about the simple solution of putting antifreeze in your cooling water?

Which CO2 laser do you have?

I got tired of waiting on my 20W (optical) diode laser. Just put a down payment on a Thunder Laser Bolt. It has an air cooled RF tube, so no freezing risk.

1 Like

Thanks for your reaction.
Antifreeze comes with biting chemicals. Some is OK but too much might damage your tube. There were some serious issues with the ducting if you use the wrong kind damaging the most expensive part of your machine. So i try to stay away from that. but still i am consider this as last resort.

We have a 100W CO2 auto bed leveling CO2 laser with the ruida RD6445… before we had the 10W sculpfun S10.

1 Like


I’m not sure what brand X-Tool use but whatever it is they recommend using it and send it with new lasers.

Anyway, with your relay board, the heater, chiller and temperature from nearest the tube tyou could certainly implement a dual point thermostat in esphome:

You could automate the set points based on your laser’s power state (if you have a way of determining this).